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Class java.lang.ThreadLocal 

java.lang.Object
    |
    +----java.lang.ThreadLocal
public class ThreadLocal
extends Object
This class provides ThreadLocal variables. These variables differ from their normal counterparts in that each thread that accesses one (via its get or set method) has its own, independently initialized copy of the variable. ThreadLocal objects are typically private static variables in classes that wish to associate state with a thread (e.g., a user ID or Transaction ID). Each thread holds an implicit.reference to its copy of a ThreadLocal as long as the thread is alive and the ThreadLocal object is accessible; after a thread goes away, all of its copies of ThreadLocal variables are subject to garbage collection (unless other references to these copies exist).

Constructor Index

o ThreadLocal()
Creates a ThreadLocal variable.

Method Index

o get()
Returns the calling thread's instance of this ThreadLocal variable.
o initialize()
Returns the calling thread's initial value for this ThreadLocal variable.
o set(Object)
Sets the calling thread's instance of this ThreadLocal variable to the given value.

Constructors

o ThreadLocal 
public ThreadLocal()
Creates a ThreadLocal variable.

Methods

o initialize 
protected Object initialize()
Returns the calling thread's initial value for this ThreadLocal variable. This method will be called once per accessing thread for each ThreadLocal, the first time each thread accesses the variable with get or set. If the programmer desires ThreadLocal variables to be initialized to some value other than null, ThreadLocal must be subclassed, and this method overridden. Typically, an anonymous inner class will be used. Typical implementations of initialize will call an appropriate constructor and return the newly constructed object.

o get 
public Object get()
Returns the calling thread's instance of this ThreadLocal variable. Initializes the instance if this is the first time the thread has called this method.

o set 
public void set(Object value)
Sets the calling thread's instance of this ThreadLocal variable to the given value. This is only used to change the value from the one assigned by the initialize method, and most applications will have no need for this functionality. 

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