java.lang

Class ThreadLocal<T>

java.lang.Object

java.lang.ThreadLocal<T>

Direct Known Subclasses:

InheritableThreadLocal

public class ThreadLocal<T>
extends Object

Implements a thread-local storage, that is, a variable for which each thread has its own value. All threads share the same ThreadLocal object, but each sees a different value when accessing it, and changes made by one thread do not affect the other threads. The implementation supports null values.

See Also:

Thread

Constructor Summary

Constructors

Constructor and Description
ThreadLocal() Creates a new thread-local variable.

Method Summary

Modifier and Type	Method and Description
T	get() Returns the value of this variable for the current thread.
protected T	initialValue() Provides the initial value of this variable for the current thread.
void	remove() Removes the entry for this variable in the current thread.
void	set(T value) Sets the value of this variable for the current thread.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ThreadLocal

public ThreadLocal()

Creates a new thread-local variable.

Method Detail

get

public T get()

Returns the value of this variable for the current thread. If an entry doesn't yet exist for this variable on this thread, this method will create an entry, populating the value with the result of initialValue().

Returns:

the current value of the variable for the calling thread.

initialValue

protected T initialValue()

Provides the initial value of this variable for the current thread. The default implementation returns null.

Returns:

the initial value of the variable.

set

public void set(T value)

Sets the value of this variable for the current thread. If set to null, the value will be set to null and the underlying entry will still be present.

Parameters:

value - the new value of the variable for the caller thread.

remove

public void remove()

Removes the entry for this variable in the current thread. If this call is followed by a get() before a set(T), #get() will call initialValue() and create a new entry with the resulting value.

Since:

1.5