java.lang

Class InheritableThreadLocal<T>


public class InheritableThreadLocal<T>
extends ThreadLocal<T>

A ThreadLocal whose value is inherited by child Threads. The value of the InheritableThreadLocal associated with the (parent) Thread is copied to the new (child) Thread at the moment of creation.

It is possible to make the value associated with the child Thread a function of the value that is associated with the parent Thread by overriding the childValue() method. The utility of this class is in transferring items like User ID or Transaction ID across threads automatically.

Since:
1.2
See Also:
ThreadLocal

Constructor Summary

InheritableThreadLocal()
Creates a new InheritableThreadLocal that has no values associated with it yet.

Method Summary

protected T
childValue(T parentValue)
Determines the value associated with a newly created child Thread as a function of the value associated with the currently executing (parent) Thread.

Methods inherited from class java.lang.ThreadLocal<T>

finalize, get, initialValue, remove, set

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

InheritableThreadLocal

public InheritableThreadLocal()
Creates a new InheritableThreadLocal that has no values associated with it yet.

Method Details

childValue

protected T childValue(T parentValue)
Determines the value associated with a newly created child Thread as a function of the value associated with the currently executing (parent) Thread. The default implementation just returns the parentValue.
Parameters:
parentValue - the value of this object in the parent thread at the moment of creation of the child
Returns:
the initial value for the child thread

InheritableThreadLocal -- a ThreadLocal which inherits values across threads Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.