public class

SingleClientConnManager

extends Object
implements ClientConnectionManager
java.lang.Object
   ↳ org.apache.http.impl.conn.SingleClientConnManager

Class Overview

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.

Summary

Nested Classes
class SingleClientConnManager.ConnAdapter The connection adapter used by this manager. 
class SingleClientConnManager.PoolEntry The pool entry for this connection manager. 
Constants
String MISUSE_MESSAGE The message to be logged on multiple allocation.
Fields
protected boolean alwaysShutDown Whether the connection should be shut down on release.
protected ClientConnectionOperator connOperator The operator for opening and updating connections.
protected long connectionExpiresTime The time the last released connection expires and shouldn't be reused.
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.
protected SchemeRegistry schemeRegistry The schemes supported by this connection manager.
protected SingleClientConnManager.PoolEntry uniquePoolEntry The one and only entry in this pool.
Public Constructors
SingleClientConnManager(HttpParams params, SchemeRegistry schreg)
Creates a new simple connection manager.
Public Methods
void closeExpiredConnections()
Closes all expired connections in the pool.
void closeIdleConnections(long idletime, TimeUnit tunit)
Closes idle connections in the pool.
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.
final ClientConnectionRequest requestConnection(HttpRoute route, Object state)
Returns a new ClientConnectionRequest, from which a ManagedClientConnection can be obtained or the request can be aborted.
void shutdown()
Shuts down this connection manager and releases allocated resources.
Protected Methods
final void assertStillUp()
Asserts that this manager is not shut down.
ClientConnectionOperator createConnectionOperator(SchemeRegistry schreg)
Hook for creating the connection operator.
void finalize()
Is called before the object's memory is being reclaimed by the VM.
void revokeConnection()
Revokes the currently issued connection.
[Expand]
Inherited Methods
From class java.lang.Object
From interface org.apache.http.conn.ClientConnectionManager

Constants

public static final String MISUSE_MESSAGE

Since: API Level 1

The message to be logged on multiple allocation.

Constant Value: "Invalid use of SingleClientConnManager: connection still allocated. Make sure to release the connection before allocating another one."

Fields

protected boolean alwaysShutDown

Since: API Level 1

Whether the connection should be shut down on release.

protected ClientConnectionOperator connOperator

Since: API Level 1

The operator for opening and updating connections.

protected long connectionExpiresTime

Since: API Level 1

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

protected boolean isShutDown

Since: API Level 1

Indicates whether this connection manager is shut down.

protected long lastReleaseTime

Since: API Level 1

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

protected SingleClientConnManager.ConnAdapter managedConn

Since: API Level 1

The currently issued managed connection, if any.

protected SchemeRegistry schemeRegistry

Since: API Level 1

The schemes supported by this connection manager.

protected SingleClientConnManager.PoolEntry uniquePoolEntry

Since: API Level 1

The one and only entry in this pool.

Public Constructors

public SingleClientConnManager (HttpParams params, SchemeRegistry schreg)

Since: API Level 1

Creates a new simple connection manager.

Parameters
params the parameters for this manager
schreg the scheme registry, or null for the default registry

Public Methods

public void closeExpiredConnections ()

Since: API Level 1

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.

public void closeIdleConnections (long idletime, TimeUnit tunit)

Since: API Level 1

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.

Parameters
idletime the idle time of connections to be closed
tunit the unit for the idletime

public ManagedClientConnection getConnection (HttpRoute route, Object state)

Since: API Level 1

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

public SchemeRegistry getSchemeRegistry ()

Since: API Level 1

Obtains the scheme registry used by this manager.

Returns
  • the scheme registry, never null

public void releaseConnection (ManagedClientConnection conn, long validDuration, TimeUnit timeUnit)

Since: API Level 1

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.

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

public final ClientConnectionRequest requestConnection (HttpRoute route, Object state)

Since: API Level 1

Returns a new ClientConnectionRequest, from which a ManagedClientConnection can be obtained or the request can be aborted.

public void shutdown ()

Since: API Level 1

Shuts down this connection manager and releases allocated resources. This includes closing all connections, whether they are currently used or not.

Protected Methods

protected final void assertStillUp ()

Since: API Level 1

Asserts that this manager is not shut down.

Throws
IllegalStateException if this manager is shut down

protected ClientConnectionOperator createConnectionOperator (SchemeRegistry schreg)

Since: API Level 1

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

protected void finalize ()

Since: API Level 1

Is called before the object's memory is being reclaimed by the VM. This can only happen once the VM has detected, during a run of the garbage collector, that the object is no longer reachable by any thread of the running application.

The method can be used to free system resources or perform other cleanup before the object is garbage collected. The default implementation of the method is empty, which is also expected by the VM, but subclasses can override finalize() as required. Uncaught exceptions which are thrown during the execution of this method cause it to terminate immediately but are otherwise ignored.

Note that the VM does guarantee that finalize() is called at most once for any object, but it doesn't guarantee when (if at all) finalize() will be called. For example, object B's finalize() can delay the execution of object A's finalize() method and therefore it can delay the reclamation of A's memory. To be safe, use a ReferenceQueue, because it provides more control over the way the VM deals with references during garbage collection.

Throws
Throwable

protected void revokeConnection ()

Since: API Level 1

Revokes the currently issued connection. The adapter gets disconnected, the connection will be shut down.