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HandlerThread

public class HandlerThread
extends Thread

java.lang.Object
   ↳ java.lang.Thread
     ↳ android.os.HandlerThread


Handy class for starting a new thread that has a looper. The looper can then be used to create handler classes. Note that start() must still be called.

Summary

Inherited constants

From class java.lang.Thread

Public constructors

HandlerThread(String name)
HandlerThread(String name, int priority)

Constructs a HandlerThread.

Public methods

Looper getLooper()

This method returns the Looper associated with this thread.

int getThreadId()

Returns the identifier of this thread.

boolean quit()

Quits the handler thread's looper.

boolean quitSafely()

Quits the handler thread's looper safely.

void run()

If this thread was constructed using a separate Runnable run object, then that Runnable object's run method is called; otherwise, this method does nothing and returns.

Protected methods

void onLooperPrepared()

Call back method that can be explicitly overridden if needed to execute some setup before Looper loops.

Inherited methods

From class java.lang.Thread
From class java.lang.Object
From interface java.lang.Runnable

Public constructors

HandlerThread

Added in API level 1
HandlerThread (String name)

Parameters
name String

HandlerThread

Added in API level 1
HandlerThread (String name, 
                int priority)

Constructs a HandlerThread.

Parameters
priority int: The priority to run the thread at. The value supplied must be from Process and not from java.lang.Thread.

Public methods

getLooper

Added in API level 1
Looper getLooper ()

This method returns the Looper associated with this thread. If this thread not been started or for any reason is isAlive() returns false, this method will return null. If this thread has been started, this method will block until the looper has been initialized.

Returns
Looper The looper.

getThreadId

Added in API level 1
int getThreadId ()

Returns the identifier of this thread. See Process.myTid().

Returns
int

quit

Added in API level 5
boolean quit ()

Quits the handler thread's looper.

Causes the handler thread's looper to terminate without processing any more messages in the message queue.

Any attempt to post messages to the queue after the looper is asked to quit will fail. For example, the sendMessage(Message) method will return false.

Using this method may be unsafe because some messages may not be delivered before the looper terminates. Consider using quitSafely() instead to ensure that all pending work is completed in an orderly manner.

Returns
boolean True if the looper looper has been asked to quit or false if the thread had not yet started running.

See also:

quitSafely

Added in API level 18
boolean quitSafely ()

Quits the handler thread's looper safely.

Causes the handler thread's looper to terminate as soon as all remaining messages in the message queue that are already due to be delivered have been handled. Pending delayed messages with due times in the future will not be delivered.

Any attempt to post messages to the queue after the looper is asked to quit will fail. For example, the sendMessage(Message) method will return false.

If the thread has not been started or has finished (that is if getLooper() returns null), then false is returned. Otherwise the looper is asked to quit and true is returned.

Returns
boolean True if the looper looper has been asked to quit or false if the thread had not yet started running.

run

Added in API level 1
void run ()

If this thread was constructed using a separate Runnable run object, then that Runnable object's run method is called; otherwise, this method does nothing and returns.

Subclasses of Thread should override this method.

Protected methods

onLooperPrepared

Added in API level 1
void onLooperPrepared ()

Call back method that can be explicitly overridden if needed to execute some setup before Looper loops.

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