## org.apache.http.impl.conn
Class SingleClientConnManager

    java.lang.Object
      org.apache.http.impl.conn.SingleClientConnManager

All Implemented Interfaces:
  ClientConnectionManager

    @ThreadSafe
    public class SingleClientConnManager

extends Object
implements ClientConnectionManager

A connection manager for a single connection. This connection manager maintains only one active connection at a time. Even though this class is thread-safe it ought to be used by one execution thread only.

SingleClientConnManager will make an effort to reuse the connection for subsequent requests with the same `route`. It will, however, close the existing connection and open it for the given route, if the route of the persistent connection does not match that of the connection request. If the connection has been already been allocated `IllegalStateException` is thrown.

Since:
  4.0

Nested Class Summary
`protected class` `SingleClientConnManager.ConnAdapter` The connection adapter used by this manager.
`protected class` `SingleClientConnManager.PoolEntry` The pool entry for this connection manager.

Field Summary
`protected boolean` `alwaysShutDown` Whether the connection should be shut down on release.
`protected long` `connectionExpiresTime` The time the last released connection expires and shouldn't be reused.
`protected ClientConnectionOperator` `connOperator` The operator for opening and updating connections.
`protected boolean` `isShutDown` Indicates whether this connection manager is shut down.
`protected long` `lastReleaseTime` The time of the last connection release, or -1.
`protected SingleClientConnManager.ConnAdapter` `managedConn` The currently issued managed connection, if any.
`static String` `MISUSE_MESSAGE` The message to be logged on multiple allocation.
`protected SchemeRegistry` `schemeRegistry` The schemes supported by this connection manager.
`protected SingleClientConnManager.PoolEntry` `uniquePoolEntry` The one and only entry in this pool.

Constructor Summary
`SingleClientConnManager()`
`SingleClientConnManager(HttpParams params, SchemeRegistry schreg)` Deprecated. use `SingleClientConnManager(SchemeRegistry)`
`SingleClientConnManager(SchemeRegistry schreg)` Creates a new simple connection manager.

Method Summary
`protected void` `assertStillUp()` Asserts that this manager is not shut down.
`void` `closeExpiredConnections()` Closes all expired connections in the pool.
`void` `closeIdleConnections(long idletime, TimeUnit tunit)` Closes idle connections in the pool.
`protected ClientConnectionOperator` `createConnectionOperator(SchemeRegistry schreg)` Hook for creating the connection operator.
`protected void` `finalize()`
`ManagedClientConnection` `getConnection(HttpRoute route, Object state)` Obtains a connection.
`SchemeRegistry` `getSchemeRegistry()` Obtains the scheme registry used by this manager.
`void` `releaseConnection(ManagedClientConnection conn, long validDuration, TimeUnit timeUnit)` Releases a connection for use by others.
`ClientConnectionRequest` `requestConnection(HttpRoute route, Object state)` Returns a new `ClientConnectionRequest`, from which a `ManagedClientConnection` can be obtained or the request can be aborted.
`protected void` `revokeConnection()` Deprecated. no longer used
`void` `shutdown()` Shuts down this connection manager and releases allocated resources.

Methods inherited from class java.lang.Object
`clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### MISUSE_MESSAGE

    public static final String MISUSE_MESSAGE

  The message to be logged on multiple allocation.

  See Also:
    Constant Field Values

### schemeRegistry

    protected final SchemeRegistry schemeRegistry

  The schemes supported by this connection manager.

### connOperator

    protected final ClientConnectionOperator connOperator

  The operator for opening and updating connections.

### alwaysShutDown

    protected final boolean alwaysShutDown

  Whether the connection should be shut down on release.

### uniquePoolEntry

    @GuardedBy(value="this")
    protected volatile SingleClientConnManager.PoolEntry uniquePoolEntry

  The one and only entry in this pool.

### managedConn

    @GuardedBy(value="this")
    protected volatile SingleClientConnManager.ConnAdapter managedConn

  The currently issued managed connection, if any.

### lastReleaseTime

    @GuardedBy(value="this")
    protected volatile long lastReleaseTime

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

### connectionExpiresTime

    @GuardedBy(value="this")
    protected volatile long connectionExpiresTime

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

### isShutDown

    protected volatile boolean isShutDown

  Indicates whether this connection manager is shut down.

Constructor Detail

### SingleClientConnManager

    @Deprecated
    public SingleClientConnManager(HttpParams params,
                                              SchemeRegistry schreg)

  Deprecated. use `SingleClientConnManager(SchemeRegistry)`

  Creates a new simple connection manager.

  Parameters:
    `params` - the parameters for this manager
    `schreg` - the scheme registry

### SingleClientConnManager

    public SingleClientConnManager(SchemeRegistry schreg)

  Creates a new simple connection manager.

  Parameters:
    `schreg` - the scheme registry

### SingleClientConnManager

    public SingleClientConnManager()

Since:
  4.1

Method Detail

### finalize

    protected void finalize()
                     throws Throwable

  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.

  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

    @Deprecated
    protected void revokeConnection()

  Deprecated. no longer used

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