Package org.apache.http.impl.conn

Class SingleClientConnManager

java.lang.Object
org.apache.http.impl.conn.SingleClientConnManager
All Implemented Interfaces:
ClientConnectionManager
public class SingleClientConnManager
extends Object
implements ClientConnectionManager
A connection "manager" for a single connection. This manager is good only for single-threaded use. Allocation always returns the connection immediately, even if it has not been released after the previous allocation. In that case, a warning is logged and the previously issued connection is revoked.

This class is derived from SimpleHttpConnectionManager in HttpClient 3. See there for original authors.

Since:
4.0
Version:
$Revision: 673450 $
Author:
Roland Weber, Michael Becke

  • Field Details

    • MISUSE_MESSAGE

      public static final String MISUSE_MESSAGE
      The message to be logged on multiple allocation.
      See Also:
      Constant Field Values

    • schemeRegistry

      protected SchemeRegistry schemeRegistry
      The schemes supported by this connection manager.

    • connOperator

      protected ClientConnectionOperator connOperator
      The operator for opening and updating connections.

    • uniquePoolEntry

      protected SingleClientConnManager.PoolEntry uniquePoolEntry
      The one and only entry in this pool.

    • managedConn

      protected SingleClientConnManager.ConnAdapter managedConn
      The currently issued managed connection, if any.

    • lastReleaseTime

      protected long lastReleaseTime
      The time of the last connection release, or -1.

    • connectionExpiresTime

      protected long connectionExpiresTime
      The time the last released connection expires and shouldn't be reused.

    • alwaysShutDown

      protected boolean alwaysShutDown
      Whether the connection should be shut down on release.

    • isShutDown

      protected volatile boolean isShutDown
      Indicates whether this connection manager is shut down.

  • Constructor Details

    • SingleClientConnManager

      public SingleClientConnManager​(HttpParams params, SchemeRegistry schreg)
      Creates a new simple connection manager.
      Parameters:
      params - the parameters for this manager
      schreg - the scheme registry

  • Method Details

    • finalize

      protected void finalize() throws Throwable
      Description copied from class: Object
      Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

      Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

      If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

      Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

      Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

      Overrides:
      finalize in class Object
      Throws:
      Throwable

    • getSchemeRegistry

      public SchemeRegistry getSchemeRegistry()
      Description copied from interface: ClientConnectionManager
      Obtains the scheme registry used by this manager.
      Specified by:
      getSchemeRegistry in interface ClientConnectionManager
      Returns:
      the scheme registry, never null

    • createConnectionOperator

      protected ClientConnectionOperator createConnectionOperator​(SchemeRegistry schreg)
      Hook for creating the connection operator. It is called by the constructor. Derived classes can override this method to change the instantiation of the operator. The default implementation here instantiates DefaultClientConnectionOperator.
      Parameters:
      schreg - the scheme registry to use, or null
      Returns:
      the connection operator to use

    • assertStillUp

      protected final void assertStillUp() throws IllegalStateException
      Asserts that this manager is not shut down.
      Throws:
      IllegalStateException - if this manager is shut down

    • requestConnection

      public final ClientConnectionRequest requestConnection​(HttpRoute route, Object state)
      Description copied from interface: ClientConnectionManager
      Returns a new ClientConnectionRequest, from which a ManagedClientConnection can be obtained or the request can be aborted.
      Specified by:
      requestConnection in interface ClientConnectionManager

    • getConnection

      public ManagedClientConnection getConnection​(HttpRoute route, Object state)
      Obtains a connection. This method does not block.
      Parameters:
      route - where the connection should point to
      Returns:
      a connection that can be used to communicate along the given route

    • releaseConnection

      public void releaseConnection​(ManagedClientConnection conn, long validDuration, TimeUnit timeUnit)
      Description copied from interface: ClientConnectionManager
      Releases a connection for use by others. You may optionally specify how long the connection is valid to be reused. Values <= 0 are considered to be valid forever. If the connection is not marked as reusable, the connection will not be reused regardless of the valid duration. If the connection has been released before, the call will be ignored.
      Specified by:
      releaseConnection in interface ClientConnectionManager
      Parameters:
      conn - the connection to release
      validDuration - the duration of time this connection is valid for reuse
      timeUnit - the unit of time validDuration is measured in
      See Also:
      ClientConnectionManager.closeExpiredConnections()

    • closeExpiredConnections

      public void closeExpiredConnections()
      Description copied from interface: ClientConnectionManager
      Closes all expired connections in the pool. Open connections in the pool that have not been used for the timespan defined when the connection was released will be closed. Currently allocated connections are not subject to this method. Times will be checked with milliseconds precision.
      Specified by:
      closeExpiredConnections in interface ClientConnectionManager

    • closeIdleConnections

      public void closeIdleConnections​(long idletime, TimeUnit tunit)
      Description copied from interface: ClientConnectionManager
      Closes idle connections in the pool. Open connections in the pool that have not been used for the timespan given by the argument will be closed. Currently allocated connections are not subject to this method. Times will be checked with milliseconds precision All expired connections will also be closed.
      Specified by:
      closeIdleConnections in interface ClientConnectionManager
      Parameters:
      idletime - the idle time of connections to be closed
      tunit - the unit for the idletime
      See Also:
      ClientConnectionManager.closeExpiredConnections()

    • shutdown

      public void shutdown()
      Description copied from interface: ClientConnectionManager
      Shuts down this connection manager and releases allocated resources. This includes closing all connections, whether they are currently used or not.
      Specified by:
      shutdown in interface ClientConnectionManager

    • revokeConnection

      protected void revokeConnection()
      Revokes the currently issued connection. The adapter gets disconnected, the connection will be shut down.