程序包 org.apache.hadoop.util

Common utilities.

请参阅: 说明

接口概要

接口	说明
IndexedSortable	Interface for collections capable of being sorted by IndexedSorter algorithms.
IndexedSorter	Interface for sort algorithms accepting IndexedSortable items.
Progressable	A facility for reporting progress.
ServicePlugin	Service plug-in interface.
Tool	A tool interface that supports handling of generic command-line options.

类概要

类	说明
ChecksumUtil
ClassUtil
CyclicIteration<K,V>	Provide an cyclic Iterator for a NavigableMap.
Daemon	A thread that has called Thread.setDaemon(boolean) with true.
DataChecksum	This class provides inteface and utilities for processing checksums for DFS data transfers.
DiskChecker	Class that provides utility functions for checking disk problem
GenericOptionsParser	GenericOptionsParser is a utility to parse command line arguments generic to the Hadoop framework.
GenericsUtil	Contains utility methods for dealing with Java Generics.
HeapSort	An implementation of the core algorithm of HeapSort.
HostsFileReader
LineReader	A class that provides a line reader from an input stream.
LinuxMemoryCalculatorPlugin	已过时 Use LinuxResourceCalculatorPlugin instead
LinuxResourceCalculatorPlugin	Plugin to calculate resource information on Linux systems.
MemoryCalculatorPlugin	已过时 Use ResourceCalculatorPlugin instead
MergeSort	An implementation of the core algorithm of MergeSort.
NativeCodeLoader	A helper to load the native hadoop code i.e. libhadoop.so.
PlatformName	A helper class for getting build-info of the java-vm.
PrintJarMainClass	A micro-application that prints the main class name out of a jar file.
PriorityQueue<T>	A PriorityQueue maintains a partial ordering of its elements such that the least element can always be found in constant time.
ProcessTree	Process tree related operations
ProcfsBasedProcessTree	A Proc file-system based ProcessTree.
ProgramDriver	A driver that is used to run programs added to it
Progress	Utility to assist with generation of progress reports.
PureJavaCrc32	A pure-java implementation of the CRC32 checksum that uses the same polynomial as the built-in native CRC32.
QueueProcessingStatistics	Hadoop has several work queues, such as FSNamesystem.neededReplications With a properly throttled queue, a worker thread cycles repeatedly, doing a chunk of work each cycle then resting a bit, until the queue is empty.
QuickSort	An implementation of the core algorithm of QuickSort.
ReflectionUtils	General reflection utils
ResourceCalculatorPlugin	Plugin to calculate resource information on the system.
ResourceCalculatorPlugin.ProcResourceValues
RunJar	Run a Hadoop job jar.
ServletUtil
Shell	A base class for running a Unix command.
Shell.ShellCommandExecutor	A simple shell command executor.
StringUtils	General string utils
ToolRunner	A utility to help run Tools.
UTF8ByteArrayUtils
VersionInfo	This class finds the package info for Hadoop and the HadoopVersionAnnotation information.
XMLUtils	General xml utilities.

枚举概要

枚举	说明
ProcessTree.Signal	The constants for the signals.
QueueProcessingStatistics.State	This enum provides the "states" of a state machine for QueueProcessingStatistics.
StringUtils.TraditionalBinaryPrefix	The traditional binary prefixes, kilo, mega, ..., exa, which can be represented by a 64-bit integer.

异常错误概要

异常错误	说明
DiskChecker.DiskErrorException
DiskChecker.DiskOutOfSpaceException
Shell.ExitCodeException	This is an IOException with exit code added.

程序包org.apache.hadoop.util的说明

Common utilities.