# Package com.hazelcast.util

This package contains classes to support the inner workings of Hazelcast as well as some backports of newer Java features / data structures to support older Java versions in a clean and nice way.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  ByteArrayProcessor | A byte array processor used to produce a byte[] out of the given one.
  ConstructorFunction<K,V> | See ConcurrencyUtil
  ExceptionUtil.RuntimeExceptionFactory | Interface used by rethrow/peel to wrap the peeled exception
  FutureUtil.ExceptionHandler | Internally used interface to define behavior of the FutureUtil methods when exceptions arise
  IConcurrentMap<K,V> | A `ConcurrentMap` with applyIfAbsent function.
  MemoryInfoAccessor | Used for providing runtime memory information of Java virtual machine.
  VersionAwareConstructorFunction<K,V> | VersionAware version of the ConstructorFunction.

- Class Summary
  Class | Description
  --- | ---
  AddressUtil | AddressUtil contains Address helper methods.
  AddressUtil.AddressHolder | Holds address
  AddressUtil.AddressMatcher | http://docs.oracle.com/javase/1.5.0/docs/guide/net/ipv6_guide/index.html
  Base64 | This class provides encode/decode for RFC 2045 Base64 as defined by RFC 2045, N.
  BitSetUtils | Convenient method for BitSet manipulations
  Clock | Abstracts the system clock to simulate different clocks without changing the actual system time.
  Clock.ClockImpl | Extend this class if you want to provide your own clock implementation.
  ClockProperties | Utility class to set system parameters for the clock implementation.
  CollectionUtil | Various collection utility methods.
  ConcurrencyUtil | Utility methods to getOrPutSynchronized and getOrPutIfAbsent in a thread safe way from a `ConcurrentMap` with a `ConstructorFunction`.
  ConcurrentReferenceHashMap<K,V> | An advanced hash table supporting configurable garbage collection semantics of keys and values, optional referential-equality, full concurrency of retrievals, and adjustable expected concurrency for updates.
  ConcurrentReferenceHashMap.SimpleEntry<K,V> |
  ContextMutexFactory | Provides reference-counted mutexes suitable for synchronization in the context of a supplied object.
  EmptyStatement | This class makes CheckStyle happy, if you have an ignored or expected exception, but need at least a single statement in the `catch` clause.
  ExceptionUtil | Contains various exception related utility methods.
  FutureUtil | This utility class contains convenience methods to work with multiple futures at the same time, e.g.
  HashUtil | Utility methods related to hash tables.
  ICMPHelper | Helper class that uses JNI to check whether the JVM process has enough permission to create raw-sockets.
  ItemCounter<T> | Non Thread-Safe Counter of things.
  IterableUtil | Utility functions for working with `Iterable`
  JsonUtil | Utility class to deal with Json.
  JVMUtil | Helper class for retrieving JVM specific information.
  MapUtil | Utility class for Maps
  MD5Util | Utility class for hashing with MD5
  MutableInteger | Mutable integer which can be used for counting purposes.
  MutableLong | Mutable long which can be used for counting purposes.
  OperatingSystemMXBeanSupport | Support class for reading attributes from OperatingSystemMXBean.
  OsHelper | Helper methods related to operating system on which the code is actually running.
  PhoneHome | Pings phone home server with cluster info daily.
  PhoneHome.PhoneHomeParameterCreator | Util class for parameters of OS and EE PhoneHome pings.
  Preconditions | A utility class for validating arguments and state.
  QueueUtil | Utility class for Queues
  QuickMath | The class `QuickMath` contains methods to perform optimized mathematical operations.
  RandomPicker | User: ahmetmircik Date: 10/7/13 Time: 12:27 PM
  RuntimeMemoryInfoAccessor | Provides memory information using `Runtime`.
  SampleableConcurrentHashMap<K,V> | ConcurrentHashMap to extend iterator capability.
  SampleableConcurrentHashMap.SamplingEntry<K,V> | Entry to define keys and values for sampling.
  ServiceLoader | Support class for loading Hazelcast services and hooks based on the Java `ServiceLoader` specification, but changed to the fact of class loaders to test for given services to work in multi classloader environments like application or OSGi servers.
  SetUtil | Utility class for Sets.
  SortingUtil | Utility class for generating Comparators to be used in sort methods specific to hazelcast classes.
  StateMachine<T extends Enum<T>> | Simple state machine using an Enum as possible states.
  StringUtil | Utility class for Strings.
  ThreadUtil | Utility class to manipulate and query thread ID.
  TimeUtil | Utility class for Time & unit conversions
  UnmodifiableIterator<E> | An iterator where items cannot be removed
  UnmodifiableListIterator<E> | A listiterator where items cannot be removed
  UuidUtil | Util class to generate type 4 (pseudo randomly generated) `UUID`.

- Enum Summary
  Enum | Description
  --- | ---
  ConcurrentReferenceHashMap.Option | Behavior-changing configuration options for the map
  ConcurrentReferenceHashMap.ReferenceType | An option specifying which Java reference type should be used to refer to a key and/or value.
  IterationType | To differentiate users selection on result collection on map-wide operations like values, keySet, query etc.

- Exception Summary
  Exception | Description
  --- | ---
  AddressUtil.InvalidAddressException | Thrown when given address is not valid.

## Package com.hazelcast.util Description

This package contains classes to support the inner workings of Hazelcast as well as some backports of newer Java features / data structures to support older Java versions in a clean and nice way. This is an internal package; so we don't provide backward compatibility on these classes.

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