# Package org.jgroups.util

Provides useful functionality which cannot be assigned to any particular other package.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  AgeOutCache.Handler<K> |
  Command | The Command patttern (see Gamma et al.).
  FutureListener<T> | A listener that is called back when a future is done.
  NotifyingFuture<T> | A sub-interface of a Future, that allows for listeners to be attached so that observers can be notified when the future completes.
  ResourceManager.IpAddressRep |
  SocketFactory | Factory to create various types of sockets.
  Streamable | Implementations of Streamable can add their state directly to the output stream, enabling them to bypass costly serialization
  ThreadDecorator | An object that can alter the state of a thread when it receives a callback from a `ThreadManager` notifying it that the thread has been created or released from use.
  ThreadFactory |
  ThreadManager | An object that manages threads and provides callbacks to a `ThreadDecorator` to allow it to alter their state.
  TimeScheduler | Timer-like interface which allows for execution of tasks.
  TimeScheduler.Task | The interface that dynamic tasks (`TimeScheduler.scheduleWithDynamicInterval(org.jgroups.util.TimeScheduler.Task)`) must implement

- Class Summary
  Class | Description
  --- | ---
  AckCollector | Collects acks from a number of nodes, waits for all acks.
  AdditionalDataUUID | Subclass of `UUID` which adds a string as payload.
  AgeOutCache<K> | Cache which removes its elements after a certain time
  BoundedList<T> | A bounded subclass of LinkedList, oldest elements are removed once max capacity is exceeded.
  Buffer | Buffer with an offset and length.
  ConcurrentLinkedBlockingQueue<T> | Attempt at writing a fast transfer queue, which is bounded.
  CreditMap | Maintains credits for senders, when credits fall below 0, a sender blocks until new credits have been received.
  DefaultSocketFactory | Default implementation, ignores service names
  DefaultThreadFactory | Thread factory mainly responsible for naming of threads.
  DefaultTimeScheduler | Implementation of `TimeScheduler` by extending `ScheduledThreadPoolExecutor` to keep tasks sorted.
  Digest | A message digest, which is used by the PBCAST layer for gossiping (also used by NAKACK for keeping track of current seqnos for all members).
  Digest.Entry | Class keeping track of the lowest and highest sequence numbers delivered, and the highest sequence numbers received, per member.
  DirectExecutor |
  ExposedByteArrayInputStream |
  ExposedByteArrayOutputStream | Extends ByteArrayOutputStream, but exposes the internal buffer.
  ExposedDataOutputStream |
  FIFOMessageQueue<K,V> | Deprecated Will be removed together with the Multiplexer in 3.0
  FixedSizeBitSet | Class copied from `BitSet`.
  GetNetworkInterfaces | Lists all network interfaces on a system
  HashedTimingWheel | Implementation of `TimeScheduler`.
  HashedTimingWheel.MyTask | Simple task wrapper, always executed by at most 1 thread.
  Headers | Open addressing based implementation of a hashmap (not supporting the Map interface though) for message headers.
  ImmutableReference<T> | Simple class that holds an immutable reference to another object (or to `null`).
  JUnitXMLReporter | Listener generating XML output suitable to be processed by JUnitReport.
  LazyThreadFactory | Lazily names threads: whenever the address or cluster name is changed, all threads are renamed
  MarshallerPool | Deprecated
  MergeId | ID to uniquely identify a merge
  Metronome |
  MutableDigest | A mutable version of Digest (which is immutable
  MyReceiver | Simple receiver which buffers all messages
  NullFuture<T> |
  PayloadUUID | Subclass of `UUID` which adds a string as payload.
  Promise<T> | Allows a thread to submit an asynchronous request and to wait for the result.
  PropertiesToXML | Iterates over all concrete Protocol classes and creates tables with Protocol's properties.
  Proxy | Redirects incoming TCP connections to other hosts/ports.
  Queue | Elements are added at the tail and removed from the head.
  Range |
  ResourceManager | Manages resources such as multicast addresses and multicast ports, and TCP ports.
  ResponseCollector<T> | Similar to AckCollector, but collects responses, not just acks.
  RetransmitTable | A store for messages to be retransmitted or delivered.
  RingBuffer<T> |
  Rsp<T> | class that represents a response from a communication
  RspList | Contains responses from all members.
  Seqno | Keeps track of a single message to retransmit
  SeqnoComparator |
  SeqnoRange | Keeps track of a range of messages to be retransmitted.
  SeqnoTable | Maintains the highest received and highest delivered seqno per member
  ShutdownRejectedExecutionHandler | ShutdownRejectedExecutionHandler is a decorator RejectedExecutionHandler used in all JGroups ThreadPoolExecutor(s).
  SingletonAddress | Address with a cluster name.
  ThreadManagerThreadPoolExecutor | ThreadPoolExecutor subclass that implements @{link ThreadManager}.
  TimeScheduler2 | Implementation of `TimeScheduler`.
  TimeScheduler2.MyTask | Simple task wrapper, always executed by at most 1 thread.
  TopologyUUID | Subclass of `UUID` which adds 3 strings (siteId, rackId and machineId)as payload.
  Triple<V1,V2,V3> | Holds 3 values, useful when we have a map with a key, but more than 1 value and we don't want to create a separate holder object for the values, and don't want to pass the values as a list or array.
  Tuple<V1,V2> | Holds 2 values, useful when we have a map with a key, but more than 1 value and we don't want to create a separate holder object for the values, and don't want to pass the values as a list or array.
  UnmodifiableVector | Vector which cannot be modified
  Util | Collection of various utility routines that can not be assigned to other classes.
  UUID | Logical address which is unique over space and time.
  XMLSchemaGenerator | Iterates over all concrete Protocol classes and creates XML schema used for validation of configuration files.

- Enum Summary
  Enum | Description
  --- | ---
  StackType |
  Util.AddressScope |

- Exception Summary
  Exception | Description
  --- | ---
  QueueClosedException |

## Package org.jgroups.util Description

Provides useful functionality which cannot be assigned to any particular other package.

Copyright © 1998-2009 Bela Ban / Red Hat. All Rights Reserved.