JavaTM 2 Platform Std. Ed. v1.5.0
java.lang
Class InheritableThreadLocal<T>
java.lang.Object
java.lang.ThreadLocal<T>
java.lang.InheritableThreadLocal<T>
public class InheritableThreadLocal<T> - extends ThreadLocal<T>
This class extends ThreadLocal to provide inheritance of values
from parent thread to child thread: when a child thread is created, the
child receives initial values for all inheritable thread-local variables
for which the parent has values. Normally the child's values will be
identical to the parent's; however, the child's value can be made an
arbitrary function of the parent's by overriding the childValue
method in this class.
Inheritable thread-local variables are used in preference to
ordinary thread-local variables when the per-thread-attribute being
maintained in the variable (e.g., User ID, Transaction ID) must be
automatically transmitted to any child threads that are created.
- Since:
- 1.2
- See Also:
ThreadLocal
Method Summary |
protected T |
childValue(T parentValue)
Computes the child's initial value for this inheritable thread-local
variable as a function of the parent's value at the time the child
thread is created. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
InheritableThreadLocal
public InheritableThreadLocal()
childValue
protected T childValue(T parentValue)
- Computes the child's initial value for this inheritable thread-local
variable as a function of the parent's value at the time the child
thread is created. This method is called from within the parent
thread before the child is started.
This method merely returns its input argument, and should be overridden
if a different behavior is desired.
- Parameters:
parentValue - the parent thread's value
- Returns:
- the child thread's initial value
Copyright 2003 Sun Microsystems, Inc. All rights reserved
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