Package org.apache.flink.util

Interface Summary

Interface	Description
AutoCloseableAsync	Closeable interface which allows to close a resource in a non blocking fashion.
CloseableIterable<T>	This interface represents an iterable that is also closeable.
CloseableIterator<T>	This interface represents an Iterator that is also AutoCloseable.
Collector<T>	Collects a record and forwards it.
Disposable	Interface for classes that can be disposed, i.e.
ExternalResource	Modified version of the jUnit ExternalResource.
IterableIterator<E>	An Iterator that is also Iterable (often by returning itself).
LinkedOptionalMap.ConsumerWithException<K,V,E extends Throwable>	A Consumer that throws exceptions.
MutableObjectIterator<E>	A simple iterator interface.
NetUtils.SocketFactory	A factory for a local socket from port number.
RefCounted	Interface to simply add reference counting functionality.
UserCodeClassLoader	UserCodeClassLoader allows to register release hooks for a user code class loader.
Visitable<T extends Visitable<T>>	This interface marks types as visitable during a traversal.
Visitor<T extends Visitable<T>>	A visitor encapsulates functionality that is applied to each node in the process of a traversal of a tree or DAG.
WrappingProxy<T>	Interface for objects that wrap another object and proxy (possibly a subset) of the methods of that object.

Class Summary

Class	Description
AbstractAutoCloseableRegistry<R extends AutoCloseable,C extends R,T,E extends Exception>	This is the abstract base class for registries that allow to register instances of Closeable, which are all closed if this registry is closed.
AbstractID	A statistically unique identification number.
ArrayUtils	Utility class for Java arrays.
ChildFirstClassLoader	A variant of the URLClassLoader that first loads from the URLs and only after that from the parent.
ClassLoaderUtil	Utilities for information with respect to class loaders, specifically class loaders for the dynamic loading of user defined classes.
CloseableIterable.Empty<T>	Empty iterator.
CloseableIterator.IteratorAdapter<E>	Adapter from Iterator to CloseableIterator.
CloseShieldOutputStream	A proxy output stream that prevents the underlying output stream from being closed.
CollectionUtil	Simple utility to work with Java collections.
CompressedSerializedValue<T>	An extension of SerializedValue that compresses the value after the serialization.
DockerImageVersions	Utility class for defining the image names and versions of Docker containers used during the Java tests.
ExceptionUtils	A collection of utility functions for dealing with exceptions and exception workflows.
ExecutorUtils	Utilities for Executors.
FatalExitExceptionHandler	Handler for uncaught exceptions that will log the exception and kill the process afterwards.
FileLock	A file lock used for avoiding race condition among multiple threads/processes.
FileUtils	This is a utility class to deal files and directories.
FlinkUserCodeClassLoader	This class loader accepts a custom handler if an exception occurs in FlinkUserCodeClassLoader.loadClass(String, boolean).
FlinkUserCodeClassLoaders	Gives the URLClassLoader a nicer name for debugging purposes.
FlinkUserCodeClassLoaders.ParentFirstClassLoader	Regular URLClassLoader that first loads from the parent and only after that from the URLs.
FlinkUserCodeClassLoaders.SafetyNetWrapperClassLoader	Ensures that holding a reference on the context class loader outliving the scope of user code does not prevent the user classloader to be garbage collected (FLINK-16245).
InstantiationUtil	Utility class to create instances from class objects and checking failure reasons.
InstantiationUtil.ClassLoaderObjectInputStream	A custom ObjectInputStream that can load classes using a specific ClassLoader.
InstantiationUtil.FailureTolerantObjectInputStream	An ObjectInputStream that ignores serialVersionUID mismatches when deserializing objects of anonymous classes or our Scala serializer classes and also replaces occurrences of GenericData.Array (from Avro) by a dummy class so that the KryoSerializer can still be deserialized without Avro being on the classpath.
IOUtils	An utility class for I/O related functionality.
IterableUtils	A collection of utilities that expand the usage of Iterable.
JarUtils	Utility functions for jar files.
LambdaUtil	This class offers utility functions for Java's lambda features.
LinkedOptionalMap<K,V>	A LinkedOptionalMap is an order preserving map (like LinkedHashMap) where keys have a unique string name, but are optionally present, and the values are optional.
LinkedOptionalMap.KeyValue<K,V>	Key-value pairs stored by the underlying map.
LinkedOptionalMap.MergeResult<K,V>	The result of merging two LinkedOptionalMaps using LinkedOptionalMap.mergeRightIntoLeft(LinkedOptionalMap, LinkedOptionalMap).
LinkedOptionalMapSerializer	LinkedOptionalMapSerializer - A serializer of LinkedOptionalMap.
LogLevelExtension	A extension that sets the log level for specific class/package loggers for a test.
LogLevelRule	A rule that sets the log level for specific class/package loggers for a test.
LongValueSequenceIterator	The LongValueSequenceIterator is an iterator that returns a sequence of numbers (as LongValue)s.
MathUtils	Collection of simple mathematical routines.
MutableURLClassLoader	URL class loader that exposes the `addURL` method in URLClassLoader.
NetUtils	Utility for various network related tasks (such as finding free ports).
NetUtils.Port	Port wrapper class which holds a FileLock until it releases.
NumberSequenceIterator	The NumberSequenceIterator is an iterator that returns a sequence of numbers (as Long)s.
OptionalConsumer<T>	Utility class which allows to run code depending on whether the optional has a value or is empty.
OptionalFailure<T>	Wrapper around an object representing either a success (with a given value) or a failure cause.
OptionalUtils	Utilities for working with Optional.
OutputTag<T>	An OutputTag is a typed and named tag to use for tagging side outputs of an operator.
Preconditions	A collection of static utility methods to validate input.
PropertiesUtil	Simple utilities for getting typed values from Properties.
Reference<T>	Wrapper class that allows to express whether the value is borrowed or owned.
ReflectionUtil	Utility for reflection operations on classes and generic type parametrization.
ReflectionUtil.FullTypeInfo	Container for the full type information of a type.
ResourceGuard	This class is a guard for shared resources with the following invariants.
SerializableObject	A simple object that only implements Serializable, so it can be used in serializable classes.
SerializedValue<T>	This class is used to transfer (via serialization) objects whose classes are not available in the system class loader.
ShutdownHookUtil	Utils class for dealing with JVM shutdown hooks.
SimpleUserCodeClassLoader	Simple UserCodeClassLoader implementation which assumes that the provided class loader will never be released and, hence, will never execute the release hooks.
SplittableIterator<T>	Abstract base class for iterators that can split themselves into multiple disjoint iterators.
StringBasedID	Base class for typed IDs that are internally represented by a string.
StringUtils	Utility class to convert objects into strings in vice-versa.
StringValueUtils	Utility class for efficient operations on StringValue.
StringValueUtils.WhitespaceTokenizer	A tokenizer for string values that uses whitespace characters as token delimiters.
TaskManagerExceptionUtils	Exception utils to handle and enrich exceptions occurring in TaskManager.
TemporaryClassLoaderContext	Sets a context class loader in a "try-with-resources" pattern.
TestLogger	Adds automatic test name logging.
TestLoggerExtension	A JUnit-5-style test logger.
TestNameProvider	A rule that provides the current test name per thread.
TestSignalHandler	This signal handler / signal logger is based on Apache Hadoop's org.apache.hadoop.util.SignalLogger.
ThrowableCatchingRunnable	This class catches all the Throwables from the wrapped runnable.
TimeUtils	Collection of utilities about time intervals.
UnionIterator<T>	An iterator that concatenates a collection of iterators.
WrappingProxyUtil	Utilities for working with WrappingProxy.
XORShiftRandom	Implement a random number generator based on the XORShift algorithm discovered by George Marsaglia.

Enum Summary

Enum	Description
FlinkUserCodeClassLoaders.ResolveOrder	Class resolution order for Flink URL ClassLoader.
OperatingSystem	An enumeration indicating the operating system that the JVM runs on.
ProcessorArchitecture	The processor architecture of the this system.
ProcessorArchitecture.MemoryAddressSize	The memory address size of the processor.
TernaryBoolean	A ternary boolean, which can have the values 'true', 'false', or 'undefined'.

Exception Summary

Exception	Description
ConfigurationException	Exception which occurs when creating a configuration object fails.
DynamicCodeLoadingException	An exception that is thrown if the dynamic instantiation of code fails.
FlinkException	Base class of all Flink-specific checked exceptions.
FlinkExpectedException	This class is just used to pass diagnostic message of some excepted procedure.
FlinkRuntimeException	Base class of all Flink-specific unchecked exceptions.
SerializedThrowable	Utility class for dealing with user-defined Throwable types that are serialized (for example during RPC/Actor communication), but cannot be resolved with the default class loader.
StateMigrationException	Base class for state migration related exceptions.
TraversableOnceException	An exception, indicating that an Iterable can only be traversed once, but has been attempted to traverse an additional time.
WrappingRuntimeException	A runtime exception that is explicitly used to wrap non-runtime exceptions.