Utils (Spark 3.4.0 JavaDoc)

Object
- org.apache.spark.util.Utils

```
public class Utils
extends Object
```
Various utility methods used by Spark.

Constructor Summary

Constructors
Constructor and Description

Utils()

Constructors
Constructor and Description
`Utils()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static String`	`BACKUP_STANDALONE_MASTER_PREFIX()` An identifier that backup masters use in their responses.
`static String`	`buildLocationMetadata(scala.collection.Seq<org.apache.hadoop.fs.Path> paths, int stopAppendingThreshold)` Convert a sequence of `Path`s to a metadata string.
`static String`	`bytesToString(scala.math.BigInt size)`
`static String`	`bytesToString(long size)` Convert a quantity in bytes to a human-readable string such as "4.0 MiB".
`static long`	`byteStringAsBytes(String str)` Convert a passed byte string (e.g.
`static long`	`byteStringAsGb(String str)` Convert a passed byte string (e.g.
`static long`	`byteStringAsKb(String str)` Convert a passed byte string (e.g.
`static long`	`byteStringAsMb(String str)` Convert a passed byte string (e.g.
`static String`	`checkAndGetK8sMasterUrl(String rawMasterURL)` Check the validity of the given Kubernetes master URL and return the resolved URL.
`static void`	`checkHost(String host)` Checks if the host contains only valid hostname/ip without port NOTE: Incase of IPV6 ip it should be enclosed inside []
`static void`	`checkHostPort(String hostPort)`
`static long`	`checkOffHeapEnabled(SparkConf sparkConf, long offHeapSize)` return 0 if MEMORY_OFFHEAP_ENABLED is false.
`static boolean`	`chmod700(java.io.File file)` JDK equivalent of `chmod 700 file`.
`static <C> Class<C>`	`classForName(String className, boolean initialize, boolean noSparkClassLoader)` Preferred alternative to Class.forName(className), as well as Class.forName(className, initialize, loader) with current thread's ContextClassLoader.
`static boolean`	`classIsLoadable(String clazz)` Determines whether the provided class is loadable in the current thread.
`static <T> T`	`clone(T value, SerializerInstance serializer, scala.reflect.ClassTag<T> evidence$2)` Clone an object using a Spark serializer.
`static java.util.Properties`	`cloneProperties(java.util.Properties props)` Create a new properties object with the same values as `props`
`static void`	`copyFileStreamNIO(java.nio.channels.FileChannel input, java.nio.channels.WritableByteChannel output, long startPosition, long bytesToCopy)`
`static long`	`copyStream(java.io.InputStream in, java.io.OutputStream out, boolean closeStreams, boolean transferToEnabled)` Copy all data from an InputStream to an OutputStream.
`static java.io.InputStream`	`copyStreamUpTo(java.io.InputStream in, long maxSize)` Copy the first `maxSize` bytes of data from the InputStream to an in-memory buffer, primarily to check for corruption.
`static boolean`	`createDirectory(java.io.File dir)` Create a directory given the abstract pathname
`static java.io.File`	`createDirectory(String root, String namePrefix)` Create a directory inside the given parent directory.
`static String`	`createFailedToGetTokenMessage(String serviceName, Throwable e)` Returns a string message about delegation token generation failure
`static String`	`createSecret(SparkConf conf)`
`static java.io.File`	`createTempDir()` Create a temporary directory inside the `java.io.tmpdir` prefixed with `spark`.
`static java.io.File`	`createTempDir(String root, String namePrefix)` Create a temporary directory inside the given parent directory.
`static String`	`decodeFileNameInURI(java.net.URI uri)` Get the file name from uri's raw path and decode it.
`static int`	`DEFAULT_DRIVER_MEM_MB()` Define a default value for driver memory here since this value is referenced across the code base and nearly all files already use Utils.scala
`static void`	`deleteRecursively(java.io.File file)` Delete a file or directory and its contents recursively.
`static <T> T`	`deserialize(byte[] bytes)` Deserialize an object using Java serialization
`static <T> T`	`deserialize(byte[] bytes, ClassLoader loader)` Deserialize an object using Java serialization and the given ClassLoader
`static long`	`deserializeLongValue(byte[] bytes)` Deserialize a Long value (used for `org.apache.spark.api.python.PythonPartitioner`)
`static void`	`deserializeViaNestedStream(java.io.InputStream is, SerializerInstance ser, scala.Function1<DeserializationStream,scala.runtime.BoxedUnit> f)` Deserialize via nested stream using specific serializer
`static boolean`	`doesDirectoryContainAnyNewFiles(java.io.File dir, long cutoff)` Determines if a directory contains any files newer than cutoff seconds.
`static java.io.File`	`doFetchFile(String url, java.io.File targetDir, String filename, SparkConf conf, org.apache.hadoop.conf.Configuration hadoopConf)` Download a file or directory to target directory.
`static scala.collection.immutable.Set<String>`	`EMPTY_USER_GROUPS()`
`static String`	`encodeFileNameToURIRawPath(String fileName)` A file name may contain some invalid URI characters, such as " ".
`static String`	`exceptionString(Throwable e)` Return a nice string representation of the exception.
`static String`	`executeAndGetOutput(scala.collection.Seq<String> command, java.io.File workingDir, scala.collection.Map<String,String> extraEnvironment, boolean redirectStderr)` Execute a command and get its output, throwing an exception if it yields a code other than 0.
`static Process`	`executeCommand(scala.collection.Seq<String> command, java.io.File workingDir, scala.collection.Map<String,String> extraEnvironment, boolean redirectStderr)` Execute a command and return the process running the command.
`static int`	`executorOffHeapMemorySizeAsMb(SparkConf sparkConf)` Convert MEMORY_OFFHEAP_SIZE to MB Unit, return 0 if MEMORY_OFFHEAP_ENABLED is false.
`static scala.Tuple2<String,Object>`	`extractHostPortFromSparkUrl(String sparkUrl)` Return a pair of host and port extracted from the `sparkUrl`.
`static java.io.File`	`fetchFile(String url, java.io.File targetDir, SparkConf conf, org.apache.hadoop.conf.Configuration hadoopConf, long timestamp, boolean useCache, boolean shouldUntar)` Download a file or directory to target directory.
`static org.apache.spark.util.CallSite`	`getCallSite(scala.Function1<String,Object> skipClass)` When called inside a class in the spark package, returns the name of the user code class (outside the spark package) that called into Spark, as well as which Spark method they called.
`static String[]`	`getConfiguredLocalDirs(SparkConf conf)` Return the configured local directories where Spark can write files.
`static ClassLoader`	`getContextOrSparkClassLoader()` Get the Context ClassLoader on this thread or, if not present, the ClassLoader that loaded Spark.
`static scala.collection.immutable.Set<String>`	`getCurrentUserGroups(SparkConf sparkConf, String username)`
`static String`	`getCurrentUserName()` Returns the current user name.
`static String`	`getDefaultPropertiesFile(scala.collection.Map<String,String> env)` Return the path of the default Spark properties file.
`static int`	`getDynamicAllocationInitialExecutors(SparkConf conf)` Return the initial number of executors for dynamic allocation.
`static long`	`getFileLength(java.io.File file, SparkConf workConf)` Return the file length, if the file is compressed it returns the uncompressed file length.
`static String`	`getFormattedClassName(Object obj)` Return the class name of the given object, removing all dollar signs
`static org.apache.hadoop.fs.FileSystem`	`getHadoopFileSystem(String path, org.apache.hadoop.conf.Configuration conf)` Return a Hadoop FileSystem with the scheme encoded in the given path.
`static org.apache.hadoop.fs.FileSystem`	`getHadoopFileSystem(java.net.URI path, org.apache.hadoop.conf.Configuration conf)` Return a Hadoop FileSystem with the scheme encoded in the given path.
`static long`	`getIteratorSize(scala.collection.Iterator<?> iterator)` Counts the number of elements of an iterator.
`static <T> scala.collection.Iterator<scala.Tuple2<T,Object>>`	`getIteratorZipWithIndex(scala.collection.Iterator<T> iter, long startIndex)` Generate a zipWithIndex iterator, avoid index value overflowing problem in scala's zipWithIndex
`static String`	`getLocalDir(SparkConf conf)` Get the path of a temporary directory.
`static scala.collection.Seq<String>`	`getLocalUserJarsForShell(SparkConf conf)` Return the local jar files which will be added to REPL's classpath.
`static String`	`getProcessName()` Returns the name of this JVM process.
`static scala.collection.Map<String,String>`	`getPropertiesFromFile(String filename)` Load properties present in the given file.
`static String`	`getSimpleName(Class<?> cls)` Safer than Class obj's getSimpleName which may throw Malformed class name error in scala.
`static ClassLoader`	`getSparkClassLoader()` Get the ClassLoader which loaded Spark.
`static String`	`getSparkOrYarnConfig(SparkConf conf, String key, String default_)` Return the value of a config either through the SparkConf or the Hadoop configuration.
`static scala.Option<String>`	`getStderr(Process process, long timeoutMs)` Return the stderr of a process after waiting for the process to terminate.
`static scala.collection.Map<String,String>`	`getSystemProperties()` Returns the system properties map that is thread-safe to iterator over.
`static ThreadStackTrace[]`	`getThreadDump()` Return a thread dump of all threads' stacktraces.
`static scala.Option<ThreadStackTrace>`	`getThreadDumpForThread(long threadId)`
`static String`	`getUsedTimeNs(long startTimeNs)` Return the string to tell how long has passed in milliseconds.
`static scala.collection.Seq<String>`	`getUserJars(SparkConf conf)` Return the jar files pointed by the "spark.jars" property.
`static void`	`initDaemon(org.slf4j.Logger log)` Utility function that should be called early in `main()` for daemons to set up some common diagnostic state.
`static <T> T`	`instantiateSerializerFromConf(org.apache.spark.internal.config.ConfigEntry<String> propertyName, SparkConf conf, boolean isDriver)`
`static <T> T`	`instantiateSerializerOrShuffleManager(String className, SparkConf conf, boolean isDriver)`
`static boolean`	`isAbsoluteURI(String path)` Check whether a path is an absolute URI.
`static boolean`	`isBindCollision(Throwable exception)` Return whether the exception is caused by an address-port collision when binding.
`static boolean`	`isClientMode(SparkConf conf)`
`static boolean`	`isDynamicAllocationEnabled(SparkConf conf)` Return whether dynamic allocation is enabled in the given conf.
`static boolean`	`isFatalError(Throwable e)` Returns true if the given exception was fatal.
`static boolean`	`isFileSplittable(org.apache.hadoop.fs.Path path, org.apache.hadoop.io.compress.CompressionCodecFactory codecFactory)` Check whether the file of the path is splittable.
`static boolean`	`isG1GC()`
`static boolean`	`isInDirectory(java.io.File parent, java.io.File child)` Return whether the specified file is a parent directory of the child file.
`static boolean`	`isInRunningSparkTask()` Returns if the current codes are running in a Spark task, e.g., in executors.
`static boolean`	`isLocalMaster(SparkConf conf)`
`static boolean`	`isLocalUri(String uri)` Returns whether the URI is a "local:" URI.
`static boolean`	`isMac()` Whether the underlying operating system is Mac OS X.
`static boolean`	`isMacOnAppleSilicon()` Whether the underlying operating system is Mac OS X and processor is Apple Silicon.
`static boolean`	`isMemberClass(Class<?> cls)` Returns true if and only if the underlying class is a member class.
`static boolean`	`isPushBasedShuffleEnabled(SparkConf conf, boolean isDriver, boolean checkSerializer)` Push based shuffle can only be enabled when below conditions are met: - the application is submitted to run in YARN mode - external shuffle service enabled - IO encryption disabled - serializer(such as KryoSerializer) supports relocation of serialized objects
`static boolean`	`isStreamingDynamicAllocationEnabled(SparkConf conf)`
`static boolean`	`isTesting()` Indicates whether Spark is currently running unit tests.
`static boolean`	`isWindows()` Whether the underlying operating system is Windows.
`static String`	`libraryPathEnvName()` Return the current system LD_LIBRARY_PATH name
`static String`	`libraryPathEnvPrefix(scala.collection.Seq<String> libraryPaths)` Return the prefix of a command that appends the given library paths to the system-specific library path environment variable.
`static String`	`loadDefaultSparkProperties(SparkConf conf, String filePath)` Load default Spark properties from the given file.
`static <T> scala.collection.Seq<T>`	`loadExtensions(Class<T> extClass, scala.collection.Seq<String> classes, SparkConf conf)` Create instances of extension classes.
`static String`	`LOCAL_SCHEME()` Scheme used for files that are locally available on worker nodes in the cluster.
`static String`	`localCanonicalHostName()` Get the local machine's FQDN.
`static String`	`localHostName()` Get the local machine's hostname.
`static String`	`localHostNameForURI()` Get the local machine's URI.
`static <T> T`	`logUncaughtExceptions(scala.Function0<T> f)` Execute the given block, logging and re-throwing any uncaught exception.
`static int`	`MAX_DIR_CREATION_ATTEMPTS()`
`static long`	`median(long[] sizes, boolean alreadySorted)` Return the median number of a long array
`static String`	`megabytesToString(long megabytes)` Convert a quantity in megabytes to a human-readable string such as "4.0 MiB".
`static int`	`memoryStringToMb(String str)` Convert a Java memory parameter passed to -Xmx (such as 300m or 1g) to a number of mebibytes.
`static String`	`msDurationToString(long ms)` Returns a human-readable string representing a duration such as "35ms"
`static String[]`	`nonLocalPaths(String paths, boolean testWindows)` Return all non-local paths from a comma-separated list of paths.
`static int`	`nonNegativeHash(Object obj)`
`static int`	`nonNegativeMod(int x, int mod)`
`static String`	`offsetBytes(scala.collection.Seq<java.io.File> files, scala.collection.Seq<Object> fileLengths, long start, long end)` Return a string containing data across a set of files.
`static String`	`offsetBytes(String path, long length, long start, long end)` Return a string containing part of a file from byte 'start' to 'end'.
`static void`	`org$apache$spark$internal$Logging$$log__$eq(org.slf4j.Logger x$1)`
`static org.slf4j.Logger`	`org$apache$spark$internal$Logging$$log_()`
`static scala.Tuple2<String,Object>`	`parseHostPort(String hostPort)`
`static String[]`	`parseStandaloneMasterUrls(String masterUrls)` Split the comma delimited string of master URLs into a list.
`static int`	`portMaxRetries(SparkConf conf)` Maximum number of retries when binding to a port before giving up.
`static boolean`	`preferIPv6()` Whether the underlying JVM prefer IPv6 addresses.
`static Thread`	`processStreamByLine(String threadName, java.io.InputStream inputStream, scala.Function1<String,scala.runtime.BoxedUnit> processLine)` Return and start a daemon thread that processes the content of the input stream line by line.
`static java.util.Random`	`random()`
`static <T> scala.collection.Seq<T>`	`randomize(scala.collection.TraversableOnce<T> seq, scala.reflect.ClassTag<T> evidence$1)` Shuffle the elements of a collection into a random order, returning the result in a new collection.
`static <T> Object`	`randomizeInPlace(Object arr, java.util.Random rand)` Shuffle the elements of an array into a random order, modifying the original array.
`static java.io.File[]`	`recursiveList(java.io.File f)` Lists files recursively.
`static scala.collection.Seq<scala.Tuple2<String,String>>`	`redact(scala.collection.Map<String,String> kvs)` Looks up the redaction regex from within the key value pairs and uses it to redact the rest of the key value pairs.
`static <K,V> scala.collection.Seq<scala.Tuple2<K,V>>`	`redact(scala.Option<scala.util.matching.Regex> regex, scala.collection.Seq<scala.Tuple2<K,V>> kvs)` Redact the sensitive values in the given map.
`static String`	`redact(scala.Option<scala.util.matching.Regex> regex, String text)` Redact the sensitive information in the given string.
`static scala.collection.Seq<scala.Tuple2<String,String>>`	`redact(SparkConf conf, scala.collection.Seq<scala.Tuple2<String,String>> kvs)` Redact the sensitive values in the given map.
`static scala.collection.Seq<String>`	`redactCommandLineArgs(SparkConf conf, scala.collection.Seq<String> commands)`
`static java.net.URI`	`resolveURI(String path)` Return a well-formed URI for the file described by a user input string.
`static String`	`resolveURIs(String paths)` Resolve a comma-separated list of paths.
`static boolean`	`responseFromBackup(String msg)` Return true if the response message is sent from a backup Master on standby.
`static String`	`sanitizeDirName(String str)`
`static <T> byte[]`	`serialize(T o)` Serialize an object using Java serialization
`static void`	`serializeViaNestedStream(java.io.OutputStream os, SerializerInstance ser, scala.Function1<SerializationStream,scala.runtime.BoxedUnit> f)` Serialize via nested stream using specific serializer
`static void`	`setCustomHostname(String hostname)` Allow setting a custom host name because when we run on Mesos we need to use the same hostname it reports to the master.
`static void`	`setLogLevel(org.apache.logging.log4j.Level l)` configure a new log4j level
`static scala.collection.Seq<String>`	`sparkJavaOpts(SparkConf conf, scala.Function1<String,Object> filterKey)` Convert all spark properties set in the given SparkConf to a sequence of java options.
`static scala.collection.Seq<String>`	`splitCommandString(String s)` Split a string of potentially quoted arguments from the command line the way that a shell would do it to determine arguments to a command.
`static <T> scala.Tuple2<T,Object>`	`startServiceOnPort(int startPort, scala.Function1<Object,scala.Tuple2<T,Object>> startService, SparkConf conf, String serviceName)` Attempt to start a service on the given port, or fail after a number of attempts.
`static int`	`stringHalfWidth(String str)` Return the number of half widths in a given string.
`static scala.collection.Seq<String>`	`stringToSeq(String str)`
`static String`	`stripDollars(String s)` Remove trailing dollar signs from qualified class name, and return the trailing part after the last dollar sign in the middle
`static String`	`substituteAppId(String opt, String appId)` Replaces all the {{APP_ID}} occurrences with the App Id.
`static String`	`substituteAppNExecIds(String opt, String appId, String execId)` Replaces all the {{EXECUTOR_ID}} occurrences with the Executor Id and {{APP_ID}} occurrences with the App Id.
`static void`	`symlink(java.io.File src, java.io.File dst)` Creates a symlink.
`static java.io.File`	`tempFileWith(java.io.File path)` Returns a path of temporary file which is in the same directory with `path`.
`static scala.Option<Object>`	`terminateProcess(Process process, long timeoutMs)` Terminates a process waiting for at most the specified duration.
`static long`	`timeIt(int numIters, scala.Function0<scala.runtime.BoxedUnit> f, scala.Option<scala.Function0<scala.runtime.BoxedUnit>> prepare)` Timing method based on iterations that permit JVM JIT optimization.
`static void`	`times(int numIters, scala.Function0<scala.runtime.BoxedUnit> f)` Method executed for repeating a task for side effects.
`static long`	`timeStringAsMs(String str)` Convert a time parameter such as (50s, 100ms, or 250us) to milliseconds for internal use.
`static long`	`timeStringAsSeconds(String str)` Convert a time parameter such as (50s, 100ms, or 250us) to seconds for internal use.
`static <T> scala.Tuple2<T,Object>`	`timeTakenMs(scala.Function0<T> body)` Records the duration of running `body`.
`static <T> scala.util.Try<T>`	`tryLog(scala.Function0<T> f)` Executes the given block in a Try, logging any uncaught exceptions.
`static void`	`tryLogNonFatalError(scala.Function0<scala.runtime.BoxedUnit> block)` Executes the given block.
`static void`	`tryOrExit(scala.Function0<scala.runtime.BoxedUnit> block)` Execute a block of code that evaluates to Unit, forwarding any uncaught exceptions to the default UncaughtExceptionHandler
`static <T> T`	`tryOrIOException(scala.Function0<T> block)` Execute a block of code that returns a value, re-throwing any non-fatal uncaught exceptions as IOException.
`static void`	`tryOrStopSparkContext(SparkContext sc, scala.Function0<scala.runtime.BoxedUnit> block)` Execute a block of code that evaluates to Unit, stop SparkContext if there is any uncaught exception
`static <R extends java.io.Closeable,T> T`	`tryWithResource(scala.Function0<R> createResource, scala.Function1<R,T> f)`
`static <T> T`	`tryWithSafeFinally(scala.Function0<T> block, scala.Function0<scala.runtime.BoxedUnit> finallyBlock)` Execute a block of code, then a finally block, but if exceptions happen in the finally block, do not suppress the original exception.
`static <T> T`	`tryWithSafeFinallyAndFailureCallbacks(scala.Function0<T> block, scala.Function0<scala.runtime.BoxedUnit> catchBlock, scala.Function0<scala.runtime.BoxedUnit> finallyBlock)` Execute a block of code and call the failure callbacks in the catch block.
`static void`	`unpack(java.io.File source, java.io.File dest)` Unpacks an archive file into the specified directory.
`static scala.collection.Seq<java.io.File>`	`unzipFilesFromFile(org.apache.hadoop.fs.FileSystem fs, org.apache.hadoop.fs.Path dfsZipFile, java.io.File localDir)` Decompress a zip file into a local dir.
`static void`	`updateSparkConfigFromProperties(SparkConf conf, scala.collection.Map<String,String> properties)` Updates Spark config with properties from a set of Properties.
`static int`	`userPort(int base, int offset)` Returns the user port to try when trying to bind a service.
`static void`	`validateURL(java.net.URI uri)` Validate that a given URI is actually a valid URL as well.
`static String`	`weakIntern(String s)` String interning to reduce the memory usage.
`static scala.util.matching.Regex`	`windowsDrive()` Pattern for matching a Windows drive, which contains only a single alphabet character.
`static <T> T`	`withContextClassLoader(ClassLoader ctxClassLoader, scala.Function0<T> fn)` Run a segment of code using a different context class loader in the current thread
`static <T> T`	`withDummyCallSite(SparkContext sc, scala.Function0<T> body)` To avoid calling `Utils.getCallSite` for every single RDD we create in the body, set a dummy call site that RDDs use instead.
`static void`	`writeByteBuffer(java.nio.ByteBuffer bb, java.io.DataOutput out)` Primitive often used when writing `ByteBuffer` to `DataOutput`
`static void`	`writeByteBuffer(java.nio.ByteBuffer bb, java.io.OutputStream out)` Primitive often used when writing `ByteBuffer` to `OutputStream`

Methods inherited from class Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Utils
```
public Utils()
```
- Method Detail
  - random
```
public static java.util.Random random()
```
  - DEFAULT_DRIVER_MEM_MB
```
public static int DEFAULT_DRIVER_MEM_MB()
```
    Define a default value for driver memory here since this value is referenced across the code base and nearly all files already use Utils.scala
    
    Returns:
    
    (undocumented)
  - MAX_DIR_CREATION_ATTEMPTS
```
public static int MAX_DIR_CREATION_ATTEMPTS()
```
  - LOCAL_SCHEME
```
public static String LOCAL_SCHEME()
```
    Scheme used for files that are locally available on worker nodes in the cluster.
  - serialize
```
public static <T> byte[] serialize(T o)
```
    Serialize an object using Java serialization
  - deserialize
```
public static <T> T deserialize(byte[] bytes)
```
    Deserialize an object using Java serialization
  - deserialize
```
public static <T> T deserialize(byte[] bytes,
                                ClassLoader loader)
```
    Deserialize an object using Java serialization and the given ClassLoader
  - deserializeLongValue
```
public static long deserializeLongValue(byte[] bytes)
```
    Deserialize a Long value (used for org.apache.spark.api.python.PythonPartitioner)
  - serializeViaNestedStream
```
public static void serializeViaNestedStream(java.io.OutputStream os,
                                            SerializerInstance ser,
                                            scala.Function1<SerializationStream,scala.runtime.BoxedUnit> f)
```
    Serialize via nested stream using specific serializer
  - deserializeViaNestedStream
```
public static void deserializeViaNestedStream(java.io.InputStream is,
                                              SerializerInstance ser,
                                              scala.Function1<DeserializationStream,scala.runtime.BoxedUnit> f)
```
    Deserialize via nested stream using specific serializer
  - weakIntern
```
public static String weakIntern(String s)
```
    String interning to reduce the memory usage.
  - getSparkClassLoader
```
public static ClassLoader getSparkClassLoader()
```
    Get the ClassLoader which loaded Spark.
    
    Returns:
    
    (undocumented)
  - getContextOrSparkClassLoader
```
public static ClassLoader getContextOrSparkClassLoader()
```
    Get the Context ClassLoader on this thread or, if not present, the ClassLoader that loaded Spark.
    This should be used whenever passing a ClassLoader to Class.ForName or finding the currently active loader when setting up ClassLoader delegation chains.
    
    Returns:
    
    (undocumented)
  - classIsLoadable
```
public static boolean classIsLoadable(String clazz)
```
    Determines whether the provided class is loadable in the current thread.
  - classForName
```
public static <C> Class<C> classForName(String className,
                                        boolean initialize,
                                        boolean noSparkClassLoader)
```
    Preferred alternative to Class.forName(className), as well as Class.forName(className, initialize, loader) with current thread's ContextClassLoader.
    
    Parameters:
    
    className - (undocumented)
    
    initialize - (undocumented)
    
    noSparkClassLoader - (undocumented)
    
    Returns:
    
    (undocumented)
  - withContextClassLoader
```
public static <T> T withContextClassLoader(ClassLoader ctxClassLoader,
                                           scala.Function0<T> fn)
```
    Run a segment of code using a different context class loader in the current thread
    
    Parameters:
    
    ctxClassLoader - (undocumented)
    
    fn - (undocumented)
    
    Returns:
    
    (undocumented)
  - writeByteBuffer
```
public static void writeByteBuffer(java.nio.ByteBuffer bb,
                                   java.io.DataOutput out)
```
    Primitive often used when writing ByteBuffer to DataOutput
    
    Parameters:
    
    bb - (undocumented)
    
    out - (undocumented)
  - writeByteBuffer
```
public static void writeByteBuffer(java.nio.ByteBuffer bb,
                                   java.io.OutputStream out)
```
    Primitive often used when writing ByteBuffer to OutputStream
    
    Parameters:
    
    bb - (undocumented)
    
    out - (undocumented)
  - chmod700
```
public static boolean chmod700(java.io.File file)
```
    JDK equivalent of chmod 700 file.
    
    Parameters:
    
    file - the file whose permissions will be modified
    
    Returns:
    
    true if the permissions were successfully changed, false otherwise.
  - createDirectory
```
public static boolean createDirectory(java.io.File dir)
```
    Create a directory given the abstract pathname
    
    Parameters:
    
    dir - (undocumented)
    
    Returns:
    
    true, if the directory is successfully created; otherwise, return false.
  - createDirectory
```
public static java.io.File createDirectory(String root,
                                           String namePrefix)
```
    Create a directory inside the given parent directory. The directory is guaranteed to be newly created, and is not marked for automatic deletion.
    
    Parameters:
    
    root - (undocumented)
    
    namePrefix - (undocumented)
    
    Returns:
    
    (undocumented)
  - createTempDir
```
public static java.io.File createTempDir()
```
    Create a temporary directory inside the java.io.tmpdir prefixed with spark. The directory will be automatically deleted when the VM shuts down.
    
    Returns:
    
    (undocumented)
  - createTempDir
```
public static java.io.File createTempDir(String root,
                                         String namePrefix)
```
    Create a temporary directory inside the given parent directory. The directory will be automatically deleted when the VM shuts down.
    
    Parameters:
    
    root - (undocumented)
    
    namePrefix - (undocumented)
    
    Returns:
    
    (undocumented)
  - copyStream
```
public static long copyStream(java.io.InputStream in,
                              java.io.OutputStream out,
                              boolean closeStreams,
                              boolean transferToEnabled)
```
    Copy all data from an InputStream to an OutputStream. NIO way of file stream to file stream copying is disabled by default unless explicitly set transferToEnabled as true, the parameter transferToEnabled should be configured by spark.file.transferTo = [true|false].
    
    Parameters:
    
    in - (undocumented)
    
    out - (undocumented)
    
    closeStreams - (undocumented)
    
    transferToEnabled - (undocumented)
    
    Returns:
    
    (undocumented)
  - copyStreamUpTo
```
public static java.io.InputStream copyStreamUpTo(java.io.InputStream in,
                                                 long maxSize)
```
    Copy the first maxSize bytes of data from the InputStream to an in-memory buffer, primarily to check for corruption.
    This returns a new InputStream which contains the same data as the original input stream. It may be entirely on in-memory buffer, or it may be a combination of in-memory data, and then continue to read from the original stream. The only real use of this is if the original input stream will potentially detect corruption while the data is being read (e.g. from compression). This allows for an eager check of corruption in the first maxSize bytes of data.
    
    Parameters:
    
    in - (undocumented)
    
    maxSize - (undocumented)
    
    Returns:
    
    An InputStream which includes all data from the original stream (combining buffered data and remaining data in the original stream)
  - copyFileStreamNIO
```
public static void copyFileStreamNIO(java.nio.channels.FileChannel input,
                                     java.nio.channels.WritableByteChannel output,
                                     long startPosition,
                                     long bytesToCopy)
```
  - encodeFileNameToURIRawPath
```
public static String encodeFileNameToURIRawPath(String fileName)
```
    A file name may contain some invalid URI characters, such as " ". This method will convert the file name to a raw path accepted by java.net.URI(String).
    Note: the file name must not contain "/" or "\"
    
    Parameters:
    
    fileName - (undocumented)
    
    Returns:
    
    (undocumented)
  - decodeFileNameInURI
```
public static String decodeFileNameInURI(java.net.URI uri)
```
    Get the file name from uri's raw path and decode it. If the raw path of uri ends with "/", return the name before the last "/".
    
    Parameters:
    
    uri - (undocumented)
    
    Returns:
    
    (undocumented)
  - fetchFile
```
public static java.io.File fetchFile(String url,
                                     java.io.File targetDir,
                                     SparkConf conf,
                                     org.apache.hadoop.conf.Configuration hadoopConf,
                                     long timestamp,
                                     boolean useCache,
                                     boolean shouldUntar)
```
    Download a file or directory to target directory. Supports fetching the file in a variety of ways, including HTTP, Hadoop-compatible filesystems, and files on a standard filesystem, based on the URL parameter. Fetching directories is only supported from Hadoop-compatible filesystems.
    If useCache is true, first attempts to fetch the file to a local cache that's shared across executors running the same application. useCache is used mainly for the executors, and not in local mode.
    Throws SparkException if the target file already exists and has different contents than the requested file.
    If shouldUntar is true, it untars the given url if it is a tar.gz or tgz into targetDir. This is a legacy behavior, and users should better use spark.archives configuration or SparkContext.addArchive
    
    Parameters:
    
    url - (undocumented)
    
    targetDir - (undocumented)
    
    conf - (undocumented)
    
    hadoopConf - (undocumented)
    
    timestamp - (undocumented)
    
    useCache - (undocumented)
    
    shouldUntar - (undocumented)
    
    Returns:
    
    (undocumented)
  - unpack
```
public static void unpack(java.io.File source,
                          java.io.File dest)
```
    Unpacks an archive file into the specified directory. It expects .jar, .zip, .tar.gz, .tgz and .tar files. This behaves same as Hadoop's archive in distributed cache. This method is basically copied from org.apache.hadoop.yarn.util.FSDownload.unpack.
    
    Parameters:
    
    source - (undocumented)
    
    dest - (undocumented)
  - timeTakenMs
```
public static <T> scala.Tuple2<T,Object> timeTakenMs(scala.Function0<T> body)
```
    Records the duration of running `body`.
  - doFetchFile
```
public static java.io.File doFetchFile(String url,
                                       java.io.File targetDir,
                                       String filename,
                                       SparkConf conf,
                                       org.apache.hadoop.conf.Configuration hadoopConf)
```
    Download a file or directory to target directory. Supports fetching the file in a variety of ways, including HTTP, Hadoop-compatible filesystems, and files on a standard filesystem, based on the URL parameter. Fetching directories is only supported from Hadoop-compatible filesystems.
    Throws SparkException if the target file already exists and has different contents than the requested file.
    
    Parameters:
    
    url - (undocumented)
    
    targetDir - (undocumented)
    
    filename - (undocumented)
    
    conf - (undocumented)
    
    hadoopConf - (undocumented)
    
    Returns:
    
    (undocumented)
  - validateURL
```
public static void validateURL(java.net.URI uri)
                        throws java.net.MalformedURLException
```
    Validate that a given URI is actually a valid URL as well.
    
    Parameters:
    
    uri - The URI to validate
    
    Throws:
    
    java.net.MalformedURLException
  - getLocalDir
```
public static String getLocalDir(SparkConf conf)
```
    Get the path of a temporary directory. Spark's local directories can be configured through multiple settings, which are used with the following precedence:
    - If called from inside of a YARN container, this will return a directory chosen by YARN. - If the SPARK_LOCAL_DIRS environment variable is set, this will return a directory from it. - Otherwise, if the spark.local.dir is set, this will return a directory from it. - Otherwise, this will return java.io.tmpdir.
    Some of these configuration options might be lists of multiple paths, but this method will always return a single directory. The return directory is chosen randomly from the array of directories it gets from getOrCreateLocalRootDirs.
    
    Parameters:
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - isInRunningSparkTask
```
public static boolean isInRunningSparkTask()
```
    Returns if the current codes are running in a Spark task, e.g., in executors.
    
    Returns:
    
    (undocumented)
  - getConfiguredLocalDirs
```
public static String[] getConfiguredLocalDirs(SparkConf conf)
```
    Return the configured local directories where Spark can write files. This method does not create any directories on its own, it only encapsulates the logic of locating the local directories according to deployment mode.
    
    Parameters:
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - randomize
```
public static <T> scala.collection.Seq<T> randomize(scala.collection.TraversableOnce<T> seq,
                                                    scala.reflect.ClassTag<T> evidence$1)
```
    Shuffle the elements of a collection into a random order, returning the result in a new collection. Unlike scala.util.Random.shuffle, this method uses a local random number generator, avoiding inter-thread contention.
    
    Parameters:
    
    seq - (undocumented)
    
    evidence$1 - (undocumented)
    
    Returns:
    
    (undocumented)
  - randomizeInPlace
```
public static <T> Object randomizeInPlace(Object arr,
                                          java.util.Random rand)
```
    Shuffle the elements of an array into a random order, modifying the original array. Returns the original array.
    
    Parameters:
    
    arr - (undocumented)
    
    rand - (undocumented)
    
    Returns:
    
    (undocumented)
  - setCustomHostname
```
public static void setCustomHostname(String hostname)
```
    Allow setting a custom host name because when we run on Mesos we need to use the same hostname it reports to the master.
    
    Parameters:
    
    hostname - (undocumented)
  - localCanonicalHostName
```
public static String localCanonicalHostName()
```
    Get the local machine's FQDN.
    
    Returns:
    
    (undocumented)
  - localHostName
```
public static String localHostName()
```
    Get the local machine's hostname. In case of IPv6, getHostAddress may return '0:0:0:0:0:0:0:1'.
    
    Returns:
    
    (undocumented)
  - localHostNameForURI
```
public static String localHostNameForURI()
```
    Get the local machine's URI.
    
    Returns:
    
    (undocumented)
  - checkHost
```
public static void checkHost(String host)
```
    Checks if the host contains only valid hostname/ip without port NOTE: Incase of IPV6 ip it should be enclosed inside []
    
    Parameters:
    
    host - (undocumented)
  - checkHostPort
```
public static void checkHostPort(String hostPort)
```
  - parseHostPort
```
public static scala.Tuple2<String,Object> parseHostPort(String hostPort)
```
  - getUsedTimeNs
```
public static String getUsedTimeNs(long startTimeNs)
```
    Return the string to tell how long has passed in milliseconds.
    
    Parameters:
    
    startTimeNs - - a timestamp in nanoseconds returned by System.nanoTime.
    
    Returns:
    
    (undocumented)
  - recursiveList
```
public static java.io.File[] recursiveList(java.io.File f)
```
    Lists files recursively.
    
    Parameters:
    
    f - (undocumented)
    
    Returns:
    
    (undocumented)
  - deleteRecursively
```
public static void deleteRecursively(java.io.File file)
```
    Delete a file or directory and its contents recursively. Don't follow directories if they are symlinks. Throws an exception if deletion is unsuccessful.
    
    Parameters:
    
    file - (undocumented)
  - doesDirectoryContainAnyNewFiles
```
public static boolean doesDirectoryContainAnyNewFiles(java.io.File dir,
                                                      long cutoff)
```
    Determines if a directory contains any files newer than cutoff seconds.
    
    Parameters:
    
    dir - must be the path to a directory, or IllegalArgumentException is thrown
    
    cutoff - measured in seconds. Returns true if there are any files or directories in the given directory whose last modified time is later than this many seconds ago
    
    Returns:
    
    (undocumented)
  - timeStringAsMs
```
public static long timeStringAsMs(String str)
```
    Convert a time parameter such as (50s, 100ms, or 250us) to milliseconds for internal use. If no suffix is provided, the passed number is assumed to be in ms.
    
    Parameters:
    
    str - (undocumented)
    
    Returns:
    
    (undocumented)
  - timeStringAsSeconds
```
public static long timeStringAsSeconds(String str)
```
    Convert a time parameter such as (50s, 100ms, or 250us) to seconds for internal use. If no suffix is provided, the passed number is assumed to be in seconds.
    
    Parameters:
    
    str - (undocumented)
    
    Returns:
    
    (undocumented)
  - byteStringAsBytes
```
public static long byteStringAsBytes(String str)
```
    Convert a passed byte string (e.g. 50b, 100k, or 250m) to bytes for internal use.
    If no suffix is provided, the passed number is assumed to be in bytes.
    
    Parameters:
    
    str - (undocumented)
    
    Returns:
    
    (undocumented)
  - byteStringAsKb
```
public static long byteStringAsKb(String str)
```
    Convert a passed byte string (e.g. 50b, 100k, or 250m) to kibibytes for internal use.
    If no suffix is provided, the passed number is assumed to be in kibibytes.
    
    Parameters:
    
    str - (undocumented)
    
    Returns:
    
    (undocumented)
  - byteStringAsMb
```
public static long byteStringAsMb(String str)
```
    Convert a passed byte string (e.g. 50b, 100k, or 250m) to mebibytes for internal use.
    If no suffix is provided, the passed number is assumed to be in mebibytes.
    
    Parameters:
    
    str - (undocumented)
    
    Returns:
    
    (undocumented)
  - byteStringAsGb
```
public static long byteStringAsGb(String str)
```
    Convert a passed byte string (e.g. 50b, 100k, or 250m, 500g) to gibibytes for internal use.
    If no suffix is provided, the passed number is assumed to be in gibibytes.
    
    Parameters:
    
    str - (undocumented)
    
    Returns:
    
    (undocumented)
  - memoryStringToMb
```
public static int memoryStringToMb(String str)
```
    Convert a Java memory parameter passed to -Xmx (such as 300m or 1g) to a number of mebibytes.
    
    Parameters:
    
    str - (undocumented)
    
    Returns:
    
    (undocumented)
  - bytesToString
```
public static String bytesToString(long size)
```
    Convert a quantity in bytes to a human-readable string such as "4.0 MiB".
    
    Parameters:
    
    size - (undocumented)
    
    Returns:
    
    (undocumented)
  - bytesToString
```
public static String bytesToString(scala.math.BigInt size)
```
  - msDurationToString
```
public static String msDurationToString(long ms)
```
    Returns a human-readable string representing a duration such as "35ms"
    
    Parameters:
    
    ms - (undocumented)
    
    Returns:
    
    (undocumented)
  - megabytesToString
```
public static String megabytesToString(long megabytes)
```
    Convert a quantity in megabytes to a human-readable string such as "4.0 MiB".
    
    Parameters:
    
    megabytes - (undocumented)
    
    Returns:
    
    (undocumented)
  - executeCommand
```
public static Process executeCommand(scala.collection.Seq<String> command,
                                     java.io.File workingDir,
                                     scala.collection.Map<String,String> extraEnvironment,
                                     boolean redirectStderr)
```
    Execute a command and return the process running the command.
    
    Parameters:
    
    command - (undocumented)
    
    workingDir - (undocumented)
    
    extraEnvironment - (undocumented)
    
    redirectStderr - (undocumented)
    
    Returns:
    
    (undocumented)
  - executeAndGetOutput
```
public static String executeAndGetOutput(scala.collection.Seq<String> command,
                                         java.io.File workingDir,
                                         scala.collection.Map<String,String> extraEnvironment,
                                         boolean redirectStderr)
```
    Execute a command and get its output, throwing an exception if it yields a code other than 0.
    
    Parameters:
    
    command - (undocumented)
    
    workingDir - (undocumented)
    
    extraEnvironment - (undocumented)
    
    redirectStderr - (undocumented)
    
    Returns:
    
    (undocumented)
  - processStreamByLine
```
public static Thread processStreamByLine(String threadName,
                                         java.io.InputStream inputStream,
                                         scala.Function1<String,scala.runtime.BoxedUnit> processLine)
```
    Return and start a daemon thread that processes the content of the input stream line by line.
    
    Parameters:
    
    threadName - (undocumented)
    
    inputStream - (undocumented)
    
    processLine - (undocumented)
    
    Returns:
    
    (undocumented)
  - tryOrExit
```
public static void tryOrExit(scala.Function0<scala.runtime.BoxedUnit> block)
```
    Execute a block of code that evaluates to Unit, forwarding any uncaught exceptions to the default UncaughtExceptionHandler
    NOTE: This method is to be called by the spark-started JVM process.
    
    Parameters:
    
    block - (undocumented)
  - tryOrStopSparkContext
```
public static void tryOrStopSparkContext(SparkContext sc,
                                         scala.Function0<scala.runtime.BoxedUnit> block)
```
    Execute a block of code that evaluates to Unit, stop SparkContext if there is any uncaught exception
    NOTE: This method is to be called by the driver-side components to avoid stopping the user-started JVM process completely; in contrast, tryOrExit is to be called in the spark-started JVM process .
    
    Parameters:
    
    sc - (undocumented)
    
    block - (undocumented)
  - tryOrIOException
```
public static <T> T tryOrIOException(scala.Function0<T> block)
```
    Execute a block of code that returns a value, re-throwing any non-fatal uncaught exceptions as IOException. This is used when implementing Externalizable and Serializable's read and write methods, since Java's serializer will not report non-IOExceptions properly; see SPARK-4080 for more context.
    
    Parameters:
    
    block - (undocumented)
    
    Returns:
    
    (undocumented)
  - tryLogNonFatalError
```
public static void tryLogNonFatalError(scala.Function0<scala.runtime.BoxedUnit> block)
```
    Executes the given block. Log non-fatal errors if any, and only throw fatal errors
  - tryWithSafeFinally
```
public static <T> T tryWithSafeFinally(scala.Function0<T> block,
                                       scala.Function0<scala.runtime.BoxedUnit> finallyBlock)
```
    Execute a block of code, then a finally block, but if exceptions happen in the finally block, do not suppress the original exception.
    This is primarily an issue with finally { out.close() } blocks, where close needs to be called to clean up out, but if an exception happened in out.write, it's likely out may be corrupted and out.close will fail as well. This would then suppress the original/likely more meaningful exception from the original out.write call.
    
    Parameters:
    
    block - (undocumented)
    
    finallyBlock - (undocumented)
    
    Returns:
    
    (undocumented)
  - tryWithSafeFinallyAndFailureCallbacks
```
public static <T> T tryWithSafeFinallyAndFailureCallbacks(scala.Function0<T> block,
                                                          scala.Function0<scala.runtime.BoxedUnit> catchBlock,
                                                          scala.Function0<scala.runtime.BoxedUnit> finallyBlock)
```
    Execute a block of code and call the failure callbacks in the catch block. If exceptions occur in either the catch or the finally block, they are appended to the list of suppressed exceptions in original exception which is then rethrown.
    This is primarily an issue with catch { abort() } or finally { out.close() } blocks, where the abort/close needs to be called to clean up out, but if an exception happened in out.write, it's likely out may be corrupted and abort or out.close will fail as well. This would then suppress the original/likely more meaningful exception from the original out.write call.
    
    Parameters:
    
    block - (undocumented)
    
    catchBlock - (undocumented)
    
    finallyBlock - (undocumented)
    
    Returns:
    
    (undocumented)
  - getCallSite
```
public static org.apache.spark.util.CallSite getCallSite(scala.Function1<String,Object> skipClass)
```
    When called inside a class in the spark package, returns the name of the user code class (outside the spark package) that called into Spark, as well as which Spark method they called. This is used, for example, to tell users where in their code each RDD got created.
    
    Parameters:
    
    skipClass - Function that is used to exclude non-user-code classes.
    
    Returns:
    
    (undocumented)
  - getFileLength
```
public static long getFileLength(java.io.File file,
                                 SparkConf workConf)
```
    Return the file length, if the file is compressed it returns the uncompressed file length. It also caches the uncompressed file size to avoid repeated decompression. The cache size is read from workerConf.
    
    Parameters:
    
    file - (undocumented)
    
    workConf - (undocumented)
    
    Returns:
    
    (undocumented)
  - offsetBytes
```
public static String offsetBytes(String path,
                                 long length,
                                 long start,
                                 long end)
```
    Return a string containing part of a file from byte 'start' to 'end'.
  - offsetBytes
```
public static String offsetBytes(scala.collection.Seq<java.io.File> files,
                                 scala.collection.Seq<Object> fileLengths,
                                 long start,
                                 long end)
```
    Return a string containing data across a set of files. The startIndex and endIndex is based on the cumulative size of all the files take in the given order. See figure below for more details.
    
    Parameters:
    
    files - (undocumented)
    
    fileLengths - (undocumented)
    
    start - (undocumented)
    
    end - (undocumented)
    
    Returns:
    
    (undocumented)
  - clone
```
public static <T> T clone(T value,
                          SerializerInstance serializer,
                          scala.reflect.ClassTag<T> evidence$2)
```
    Clone an object using a Spark serializer.
    
    Parameters:
    
    value - (undocumented)
    
    serializer - (undocumented)
    
    evidence$2 - (undocumented)
    
    Returns:
    
    (undocumented)
  - splitCommandString
```
public static scala.collection.Seq<String> splitCommandString(String s)
```
    Split a string of potentially quoted arguments from the command line the way that a shell would do it to determine arguments to a command. For example, if the string is 'a "b c" d', then it would be parsed as three arguments: 'a', 'b c' and 'd'.
    
    Parameters:
    
    s - (undocumented)
    
    Returns:
    
    (undocumented)
  - nonNegativeMod
```
public static int nonNegativeMod(int x,
                                 int mod)
```
  - nonNegativeHash
```
public static int nonNegativeHash(Object obj)
```
  - getSystemProperties
```
public static scala.collection.Map<String,String> getSystemProperties()
```
    Returns the system properties map that is thread-safe to iterator over. It gets the properties which have been set explicitly, as well as those for which only a default value has been defined.
    
    Returns:
    
    (undocumented)
  - times
```
public static void times(int numIters,
                         scala.Function0<scala.runtime.BoxedUnit> f)
```
    Method executed for repeating a task for side effects. Unlike a for comprehension, it permits JVM JIT optimization
    
    Parameters:
    
    numIters - (undocumented)
    
    f - (undocumented)
  - timeIt
```
public static long timeIt(int numIters,
                          scala.Function0<scala.runtime.BoxedUnit> f,
                          scala.Option<scala.Function0<scala.runtime.BoxedUnit>> prepare)
```
    Timing method based on iterations that permit JVM JIT optimization.
    
    Parameters:
    
    numIters - number of iterations
    
    f - function to be executed. If prepare is not None, the running time of each call to f must be an order of magnitude longer than one nanosecond for accurate timing.
    
    prepare - function to be executed before each call to f. Its running time doesn't count.
    
    Returns:
    
    the total time across all iterations (not counting preparation time) in nanoseconds.
  - getIteratorSize
```
public static long getIteratorSize(scala.collection.Iterator<?> iterator)
```
    Counts the number of elements of an iterator.
    
    Parameters:
    
    iterator - (undocumented)
    
    Returns:
    
    (undocumented)
  - getIteratorZipWithIndex
```
public static <T> scala.collection.Iterator<scala.Tuple2<T,Object>> getIteratorZipWithIndex(scala.collection.Iterator<T> iter,
                                                                                            long startIndex)
```
    Generate a zipWithIndex iterator, avoid index value overflowing problem in scala's zipWithIndex
    
    Parameters:
    
    iter - (undocumented)
    
    startIndex - (undocumented)
    
    Returns:
    
    (undocumented)
  - symlink
```
public static void symlink(java.io.File src,
                           java.io.File dst)
```
    Creates a symlink.
    
    Parameters:
    
    src - absolute path to the source
    
    dst - relative path for the destination
  - getFormattedClassName
```
public static String getFormattedClassName(Object obj)
```
    Return the class name of the given object, removing all dollar signs
  - getHadoopFileSystem
```
public static org.apache.hadoop.fs.FileSystem getHadoopFileSystem(java.net.URI path,
                                                                  org.apache.hadoop.conf.Configuration conf)
```
    Return a Hadoop FileSystem with the scheme encoded in the given path.
    
    Parameters:
    
    path - (undocumented)
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - getHadoopFileSystem
```
public static org.apache.hadoop.fs.FileSystem getHadoopFileSystem(String path,
                                                                  org.apache.hadoop.conf.Configuration conf)
```
    Return a Hadoop FileSystem with the scheme encoded in the given path.
    
    Parameters:
    
    path - (undocumented)
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - isWindows
```
public static boolean isWindows()
```
    Whether the underlying operating system is Windows.
    
    Returns:
    
    (undocumented)
  - isMac
```
public static boolean isMac()
```
    Whether the underlying operating system is Mac OS X.
    
    Returns:
    
    (undocumented)
  - isMacOnAppleSilicon
```
public static boolean isMacOnAppleSilicon()
```
    Whether the underlying operating system is Mac OS X and processor is Apple Silicon.
    
    Returns:
    
    (undocumented)
  - preferIPv6
```
public static boolean preferIPv6()
```
    Whether the underlying JVM prefer IPv6 addresses.
    
    Returns:
    
    (undocumented)
  - windowsDrive
```
public static scala.util.matching.Regex windowsDrive()
```
    Pattern for matching a Windows drive, which contains only a single alphabet character.
    
    Returns:
    
    (undocumented)
  - isTesting
```
public static boolean isTesting()
```
    Indicates whether Spark is currently running unit tests.
    
    Returns:
    
    (undocumented)
  - terminateProcess
```
public static scala.Option<Object> terminateProcess(Process process,
                                                    long timeoutMs)
```
    Terminates a process waiting for at most the specified duration.
    
    Parameters:
    
    process - (undocumented)
    
    timeoutMs - (undocumented)
    
    Returns:
    
    the process exit value if it was successfully terminated, else None
  - getStderr
```
public static scala.Option<String> getStderr(Process process,
                                             long timeoutMs)
```
    Return the stderr of a process after waiting for the process to terminate. If the process does not terminate within the specified timeout, return None.
    
    Parameters:
    
    process - (undocumented)
    
    timeoutMs - (undocumented)
    
    Returns:
    
    (undocumented)
  - logUncaughtExceptions
```
public static <T> T logUncaughtExceptions(scala.Function0<T> f)
```
    Execute the given block, logging and re-throwing any uncaught exception. This is particularly useful for wrapping code that runs in a thread, to ensure that exceptions are printed, and to avoid having to catch Throwable.
    
    Parameters:
    
    f - (undocumented)
    
    Returns:
    
    (undocumented)
  - tryLog
```
public static <T> scala.util.Try<T> tryLog(scala.Function0<T> f)
```
    Executes the given block in a Try, logging any uncaught exceptions.
  - isFatalError
```
public static boolean isFatalError(Throwable e)
```
    Returns true if the given exception was fatal. See docs for scala.util.control.NonFatal.
  - resolveURI
```
public static java.net.URI resolveURI(String path)
```
    Return a well-formed URI for the file described by a user input string.
    If the supplied path does not contain a scheme, or is a relative path, it will be converted into an absolute path with a file:// scheme.
    
    Parameters:
    
    path - (undocumented)
    
    Returns:
    
    (undocumented)
  - resolveURIs
```
public static String resolveURIs(String paths)
```
    Resolve a comma-separated list of paths.
  - isAbsoluteURI
```
public static boolean isAbsoluteURI(String path)
```
    Check whether a path is an absolute URI.
  - nonLocalPaths
```
public static String[] nonLocalPaths(String paths,
                                     boolean testWindows)
```
    Return all non-local paths from a comma-separated list of paths.
  - loadDefaultSparkProperties
```
public static String loadDefaultSparkProperties(SparkConf conf,
                                                String filePath)
```
    Load default Spark properties from the given file. If no file is provided, use the common defaults file. This mutates state in the given SparkConf and in this JVM's system properties if the config specified in the file is not already set. Return the path of the properties file used.
    
    Parameters:
    
    conf - (undocumented)
    
    filePath - (undocumented)
    
    Returns:
    
    (undocumented)
  - updateSparkConfigFromProperties
```
public static void updateSparkConfigFromProperties(SparkConf conf,
                                                   scala.collection.Map<String,String> properties)
```
    Updates Spark config with properties from a set of Properties. Provided properties have the highest priority.
    
    Parameters:
    
    conf - (undocumented)
    
    properties - (undocumented)
  - getPropertiesFromFile
```
public static scala.collection.Map<String,String> getPropertiesFromFile(String filename)
```
    Load properties present in the given file.
  - getDefaultPropertiesFile
```
public static String getDefaultPropertiesFile(scala.collection.Map<String,String> env)
```
    Return the path of the default Spark properties file.
  - exceptionString
```
public static String exceptionString(Throwable e)
```
    Return a nice string representation of the exception. It will call "printStackTrace" to recursively generate the stack trace including the exception and its causes.
    
    Parameters:
    
    e - (undocumented)
    
    Returns:
    
    (undocumented)
  - getThreadDump
```
public static ThreadStackTrace[] getThreadDump()
```
    Return a thread dump of all threads' stacktraces. Used to capture dumps for the web UI
  - getThreadDumpForThread
```
public static scala.Option<ThreadStackTrace> getThreadDumpForThread(long threadId)
```
  - sparkJavaOpts
```
public static scala.collection.Seq<String> sparkJavaOpts(SparkConf conf,
                                                         scala.Function1<String,Object> filterKey)
```
    Convert all spark properties set in the given SparkConf to a sequence of java options.
    
    Parameters:
    
    conf - (undocumented)
    
    filterKey - (undocumented)
    
    Returns:
    
    (undocumented)
  - portMaxRetries
```
public static int portMaxRetries(SparkConf conf)
```
    Maximum number of retries when binding to a port before giving up.
    
    Parameters:
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - userPort
```
public static int userPort(int base,
                           int offset)
```
    Returns the user port to try when trying to bind a service. Handles wrapping and skipping privileged ports.
    
    Parameters:
    
    base - (undocumented)
    
    offset - (undocumented)
    
    Returns:
    
    (undocumented)
  - startServiceOnPort
```
public static <T> scala.Tuple2<T,Object> startServiceOnPort(int startPort,
                                                            scala.Function1<Object,scala.Tuple2<T,Object>> startService,
                                                            SparkConf conf,
                                                            String serviceName)
```
    Attempt to start a service on the given port, or fail after a number of attempts. Each subsequent attempt uses 1 + the port used in the previous attempt (unless the port is 0).
    
    Parameters:
    
    startPort - The initial port to start the service on.
    
    startService - Function to start service on a given port. This is expected to throw java.net.BindException on port collision.
    
    conf - A SparkConf used to get the maximum number of retries when binding to a port.
    
    serviceName - Name of the service.
    
    Returns:
    
    (service: T, port: Int)
  - isBindCollision
```
public static boolean isBindCollision(Throwable exception)
```
    Return whether the exception is caused by an address-port collision when binding.
    
    Parameters:
    
    exception - (undocumented)
    
    Returns:
    
    (undocumented)
  - setLogLevel
```
public static void setLogLevel(org.apache.logging.log4j.Level l)
```
    configure a new log4j level
    
    Parameters:
    
    l - (undocumented)
  - libraryPathEnvName
```
public static String libraryPathEnvName()
```
    Return the current system LD_LIBRARY_PATH name
    
    Returns:
    
    (undocumented)
  - libraryPathEnvPrefix
```
public static String libraryPathEnvPrefix(scala.collection.Seq<String> libraryPaths)
```
    Return the prefix of a command that appends the given library paths to the system-specific library path environment variable. On Unix, for instance, this returns the string LD_LIBRARY_PATH="path1:path2:$LD_LIBRARY_PATH".
    
    Parameters:
    
    libraryPaths - (undocumented)
    
    Returns:
    
    (undocumented)
  - getSparkOrYarnConfig
```
public static String getSparkOrYarnConfig(SparkConf conf,
                                          String key,
                                          String default_)
```
    Return the value of a config either through the SparkConf or the Hadoop configuration. We Check whether the key is set in the SparkConf before look at any Hadoop configuration. If the key is set in SparkConf, no matter whether it is running on YARN or not, gets the value from SparkConf. Only when the key is not set in SparkConf and running on YARN, gets the value from Hadoop configuration.
    
    Parameters:
    
    conf - (undocumented)
    
    key - (undocumented)
    
    default_ - (undocumented)
    
    Returns:
    
    (undocumented)
  - extractHostPortFromSparkUrl
```
public static scala.Tuple2<String,Object> extractHostPortFromSparkUrl(String sparkUrl)
                                                               throws SparkException
```
    Return a pair of host and port extracted from the sparkUrl.
    A spark url (spark://host:port) is a special URI that its scheme is spark and only contains host and port.
    
    Parameters:
    
    sparkUrl - (undocumented)
    
    Returns:
    
    (undocumented)
    
    Throws:
    
    SparkException - if sparkUrl is invalid.
  - getCurrentUserName
```
public static String getCurrentUserName()
```
    Returns the current user name. This is the currently logged in user, unless that's been overridden by the SPARK_USER environment variable.
    
    Returns:
    
    (undocumented)
  - EMPTY_USER_GROUPS
```
public static scala.collection.immutable.Set<String> EMPTY_USER_GROUPS()
```
  - getCurrentUserGroups
```
public static scala.collection.immutable.Set<String> getCurrentUserGroups(SparkConf sparkConf,
                                                                          String username)
```
  - parseStandaloneMasterUrls
```
public static String[] parseStandaloneMasterUrls(String masterUrls)
```
    Split the comma delimited string of master URLs into a list. For instance, "spark://abc,def" becomes [spark://abc, spark://def].
    
    Parameters:
    
    masterUrls - (undocumented)
    
    Returns:
    
    (undocumented)
  - BACKUP_STANDALONE_MASTER_PREFIX
```
public static String BACKUP_STANDALONE_MASTER_PREFIX()
```
    An identifier that backup masters use in their responses.
  - responseFromBackup
```
public static boolean responseFromBackup(String msg)
```
    Return true if the response message is sent from a backup Master on standby.
  - withDummyCallSite
```
public static <T> T withDummyCallSite(SparkContext sc,
                                      scala.Function0<T> body)
```
    To avoid calling Utils.getCallSite for every single RDD we create in the body, set a dummy call site that RDDs use instead. This is for performance optimization.
    
    Parameters:
    
    sc - (undocumented)
    
    body - (undocumented)
    
    Returns:
    
    (undocumented)
  - isInDirectory
```
public static boolean isInDirectory(java.io.File parent,
                                    java.io.File child)
```
    Return whether the specified file is a parent directory of the child file.
    
    Parameters:
    
    parent - (undocumented)
    
    child - (undocumented)
    
    Returns:
    
    (undocumented)
  - isLocalMaster
```
public static boolean isLocalMaster(SparkConf conf)
```
    Parameters:
    
    conf - (undocumented)
    
    Returns:
    
    whether it is local mode
  - isPushBasedShuffleEnabled
```
public static boolean isPushBasedShuffleEnabled(SparkConf conf,
                                                boolean isDriver,
                                                boolean checkSerializer)
```
    Push based shuffle can only be enabled when below conditions are met: - the application is submitted to run in YARN mode - external shuffle service enabled - IO encryption disabled - serializer(such as KryoSerializer) supports relocation of serialized objects
    
    Parameters:
    
    conf - (undocumented)
    
    isDriver - (undocumented)
    
    checkSerializer - (undocumented)
    
    Returns:
    
    (undocumented)
  - instantiateSerializerOrShuffleManager
```
public static <T> T instantiateSerializerOrShuffleManager(String className,
                                                          SparkConf conf,
                                                          boolean isDriver)
```
  - instantiateSerializerFromConf
```
public static <T> T instantiateSerializerFromConf(org.apache.spark.internal.config.ConfigEntry<String> propertyName,
                                                  SparkConf conf,
                                                  boolean isDriver)
```
  - isDynamicAllocationEnabled
```
public static boolean isDynamicAllocationEnabled(SparkConf conf)
```
    Return whether dynamic allocation is enabled in the given conf.
    
    Parameters:
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - isStreamingDynamicAllocationEnabled
```
public static boolean isStreamingDynamicAllocationEnabled(SparkConf conf)
```
  - getDynamicAllocationInitialExecutors
```
public static int getDynamicAllocationInitialExecutors(SparkConf conf)
```
    Return the initial number of executors for dynamic allocation.
    
    Parameters:
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - tryWithResource
```
public static <R extends java.io.Closeable,T> T tryWithResource(scala.Function0<R> createResource,
                                                                scala.Function1<R,T> f)
```
  - tempFileWith
```
public static java.io.File tempFileWith(java.io.File path)
```
    Returns a path of temporary file which is in the same directory with path.
    
    Parameters:
    
    path - (undocumented)
    
    Returns:
    
    (undocumented)
  - getProcessName
```
public static String getProcessName()
```
    Returns the name of this JVM process. This is OS dependent but typically (OSX, Linux, Windows), this is formatted as PID@hostname.
    
    Returns:
    
    (undocumented)
  - initDaemon
```
public static void initDaemon(org.slf4j.Logger log)
```
    Utility function that should be called early in main() for daemons to set up some common diagnostic state.
    
    Parameters:
    
    log - (undocumented)
  - getUserJars
```
public static scala.collection.Seq<String> getUserJars(SparkConf conf)
```
    Return the jar files pointed by the "spark.jars" property. Spark internally will distribute these jars through file server. In the YARN mode, it will return an empty list, since YARN has its own mechanism to distribute jars.
    
    Parameters:
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - getLocalUserJarsForShell
```
public static scala.collection.Seq<String> getLocalUserJarsForShell(SparkConf conf)
```
    Return the local jar files which will be added to REPL's classpath. These jar files are specified by --jars (spark.jars) or --packages, remote jars will be downloaded to local by SparkSubmit at first.
    
    Parameters:
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - redact
```
public static scala.collection.Seq<scala.Tuple2<String,String>> redact(SparkConf conf,
                                                                       scala.collection.Seq<scala.Tuple2<String,String>> kvs)
```
    Redact the sensitive values in the given map. If a map key matches the redaction pattern then its value is replaced with a dummy text.
    
    Parameters:
    
    conf - (undocumented)
    
    kvs - (undocumented)
    
    Returns:
    
    (undocumented)
  - redact
```
public static <K,V> scala.collection.Seq<scala.Tuple2<K,V>> redact(scala.Option<scala.util.matching.Regex> regex,
                                                                   scala.collection.Seq<scala.Tuple2<K,V>> kvs)
```
    Redact the sensitive values in the given map. If a map key matches the redaction pattern then its value is replaced with a dummy text.
    
    Parameters:
    
    regex - (undocumented)
    
    kvs - (undocumented)
    
    Returns:
    
    (undocumented)
  - redact
```
public static String redact(scala.Option<scala.util.matching.Regex> regex,
                            String text)
```
    Redact the sensitive information in the given string.
    
    Parameters:
    
    regex - (undocumented)
    
    text - (undocumented)
    
    Returns:
    
    (undocumented)
  - redact
```
public static scala.collection.Seq<scala.Tuple2<String,String>> redact(scala.collection.Map<String,String> kvs)
```
    Looks up the redaction regex from within the key value pairs and uses it to redact the rest of the key value pairs. No care is taken to make sure the redaction property itself is not redacted. So theoretically, the property itself could be configured to redact its own value when printing.
    
    Parameters:
    
    kvs - (undocumented)
    
    Returns:
    
    (undocumented)
  - redactCommandLineArgs
```
public static scala.collection.Seq<String> redactCommandLineArgs(SparkConf conf,
                                                                 scala.collection.Seq<String> commands)
```
  - stringToSeq
```
public static scala.collection.Seq<String> stringToSeq(String str)
```
  - loadExtensions
```
public static <T> scala.collection.Seq<T> loadExtensions(Class<T> extClass,
                                                         scala.collection.Seq<String> classes,
                                                         SparkConf conf)
```
    Create instances of extension classes.
    The classes in the given list must: - Be sub-classes of the given base class. - Provide either a no-arg constructor, or a 1-arg constructor that takes a SparkConf.
    The constructors are allowed to throw "UnsupportedOperationException" if the extension does not want to be registered; this allows the implementations to check the Spark configuration (or other state) and decide they do not need to be added. A log message is printed in that case. Other exceptions are bubbled up.
    
    Parameters:
    
    extClass - (undocumented)
    
    classes - (undocumented)
    
    conf - (undocumented)
    
    Returns:
    
    (undocumented)
  - checkAndGetK8sMasterUrl
```
public static String checkAndGetK8sMasterUrl(String rawMasterURL)
```
    Check the validity of the given Kubernetes master URL and return the resolved URL. Prefix "k8s://" is appended to the resolved URL as the prefix is used by KubernetesClusterManager in canCreate to determine if the KubernetesClusterManager should be used.
    
    Parameters:
    
    rawMasterURL - (undocumented)
    
    Returns:
    
    (undocumented)
  - substituteAppNExecIds
```
public static String substituteAppNExecIds(String opt,
                                           String appId,
                                           String execId)
```
    Replaces all the {{EXECUTOR_ID}} occurrences with the Executor Id and {{APP_ID}} occurrences with the App Id.
    
    Parameters:
    
    opt - (undocumented)
    
    appId - (undocumented)
    
    execId - (undocumented)
    
    Returns:
    
    (undocumented)
  - substituteAppId
```
public static String substituteAppId(String opt,
                                     String appId)
```
    Replaces all the {{APP_ID}} occurrences with the App Id.
    
    Parameters:
    
    opt - (undocumented)
    
    appId - (undocumented)
    
    Returns:
    
    (undocumented)
  - createSecret
```
public static String createSecret(SparkConf conf)
```
  - isMemberClass
```
public static boolean isMemberClass(Class<?> cls)
```
    Returns true if and only if the underlying class is a member class.
    Note: jdk8u throws a "Malformed class name" error if a given class is a deeply-nested inner class (See SPARK-34607 for details). This issue has already been fixed in jdk9+, so we can remove this helper method safely if we drop the support of jdk8u.
    
    Parameters:
    
    cls - (undocumented)
    
    Returns:
    
    (undocumented)
  - getSimpleName
```
public static String getSimpleName(Class<?> cls)
```
    Safer than Class obj's getSimpleName which may throw Malformed class name error in scala. This method mimics scalatest's getSimpleNameOfAnObjectsClass.
    
    Parameters:
    
    cls - (undocumented)
    
    Returns:
    
    (undocumented)
  - stripDollars
```
public static String stripDollars(String s)
```
    Remove trailing dollar signs from qualified class name, and return the trailing part after the last dollar sign in the middle
    
    Parameters:
    
    s - (undocumented)
    
    Returns:
    
    (undocumented)
  - stringHalfWidth
```
public static int stringHalfWidth(String str)
```
    Return the number of half widths in a given string. Note that a full width character occupies two half widths.
    For a string consisting of 1 million characters, the execution of this method requires about 50ms.
    
    Parameters:
    
    str - (undocumented)
    
    Returns:
    
    (undocumented)
  - sanitizeDirName
```
public static String sanitizeDirName(String str)
```
  - isClientMode
```
public static boolean isClientMode(SparkConf conf)
```
  - isLocalUri
```
public static boolean isLocalUri(String uri)
```
    Returns whether the URI is a "local:" URI.
  - isFileSplittable
```
public static boolean isFileSplittable(org.apache.hadoop.fs.Path path,
                                       org.apache.hadoop.io.compress.CompressionCodecFactory codecFactory)
```
    Check whether the file of the path is splittable.
  - cloneProperties
```
public static java.util.Properties cloneProperties(java.util.Properties props)
```
    Create a new properties object with the same values as `props`
  - buildLocationMetadata
```
public static String buildLocationMetadata(scala.collection.Seq<org.apache.hadoop.fs.Path> paths,
                                           int stopAppendingThreshold)
```
    Convert a sequence of Paths to a metadata string. When the length of metadata string exceeds stopAppendingThreshold, stop appending paths for saving memory.
    
    Parameters:
    
    paths - (undocumented)
    
    stopAppendingThreshold - (undocumented)
    
    Returns:
    
    (undocumented)
  - executorOffHeapMemorySizeAsMb
```
public static int executorOffHeapMemorySizeAsMb(SparkConf sparkConf)
```
    Convert MEMORY_OFFHEAP_SIZE to MB Unit, return 0 if MEMORY_OFFHEAP_ENABLED is false.
    
    Parameters:
    
    sparkConf - (undocumented)
    
    Returns:
    
    (undocumented)
  - checkOffHeapEnabled
```
public static long checkOffHeapEnabled(SparkConf sparkConf,
                                       long offHeapSize)
```
    return 0 if MEMORY_OFFHEAP_ENABLED is false.
    
    Parameters:
    
    sparkConf - (undocumented)
    
    offHeapSize - (undocumented)
    
    Returns:
    
    (undocumented)
  - createFailedToGetTokenMessage
```
public static String createFailedToGetTokenMessage(String serviceName,
                                                   Throwable e)
```
    Returns a string message about delegation token generation failure
  - unzipFilesFromFile
```
public static scala.collection.Seq<java.io.File> unzipFilesFromFile(org.apache.hadoop.fs.FileSystem fs,
                                                                    org.apache.hadoop.fs.Path dfsZipFile,
                                                                    java.io.File localDir)
```
    Decompress a zip file into a local dir. File names are read from the zip file. Note, we skip addressing the directory here. Also, we rely on the caller side to address any exceptions.
    
    Parameters:
    
    fs - (undocumented)
    
    dfsZipFile - (undocumented)
    
    localDir - (undocumented)
    
    Returns:
    
    (undocumented)
  - median
```
public static long median(long[] sizes,
                          boolean alreadySorted)
```
    Return the median number of a long array
    
    Parameters:
    
    sizes -
    
    alreadySorted -
    
    Returns:
  - isG1GC
```
public static boolean isG1GC()
```
  - org$apache$spark$internal$Logging$$log_
```
public static org.slf4j.Logger org$apache$spark$internal$Logging$$log_()
```
  - org$apache$spark$internal$Logging$$log__$eq
```
public static void org$apache$spark$internal$Logging$$log__$eq(org.slf4j.Logger x$1)
```

Class Utils

Constructor Summary

Method Summary

Methods inherited from class Object

Constructor Detail

Utils

Method Detail

random

DEFAULT_DRIVER_MEM_MB

MAX_DIR_CREATION_ATTEMPTS

LOCAL_SCHEME

serialize

deserialize

deserialize

deserializeLongValue

serializeViaNestedStream

deserializeViaNestedStream

weakIntern

getSparkClassLoader

getContextOrSparkClassLoader

classIsLoadable

classForName

withContextClassLoader

writeByteBuffer

writeByteBuffer

chmod700

createDirectory

createDirectory

createTempDir

createTempDir

copyStream

copyStreamUpTo

copyFileStreamNIO

encodeFileNameToURIRawPath

decodeFileNameInURI

fetchFile

unpack

timeTakenMs

doFetchFile

validateURL

getLocalDir

isInRunningSparkTask

getConfiguredLocalDirs

randomize

randomizeInPlace

setCustomHostname

localCanonicalHostName

localHostName

localHostNameForURI

checkHost

checkHostPort

parseHostPort

getUsedTimeNs

recursiveList

deleteRecursively

doesDirectoryContainAnyNewFiles

timeStringAsMs

timeStringAsSeconds

byteStringAsBytes

byteStringAsKb

byteStringAsMb

byteStringAsGb

memoryStringToMb

bytesToString

bytesToString

msDurationToString

megabytesToString

executeCommand

executeAndGetOutput

processStreamByLine

tryOrExit

tryOrStopSparkContext

tryOrIOException

tryLogNonFatalError

tryWithSafeFinally

tryWithSafeFinallyAndFailureCallbacks

getCallSite

getFileLength

offsetBytes

offsetBytes