Android APIs
public class

HandlerThread

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

Class Overview

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

[Expand]
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()
Calls the run() method of the Runnable object the receiver holds.
Protected Methods
void onLooperPrepared()
Call back method that can be explicitly overridden if needed to execute some setup before Looper loops.
[Expand]
Inherited Methods
From class java.lang.Thread
From class java.lang.Object
From interface java.lang.Runnable

Public Constructors

public HandlerThread (String name)

Added in API level 1

Parameters
name

public HandlerThread (String name, int priority)

Added in API level 1

Constructs a HandlerThread.

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

Public Methods

public Looper getLooper ()

Added in API level 1

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.

public int getThreadId ()

Added in API level 1

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

Returns
int

public boolean quit ()

Added in API level 5

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:

public boolean quitSafely ()

Added in API level 18

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.

public void run ()

Added in API level 1

Calls the run() method of the Runnable object the receiver holds. If no Runnable is set, does nothing.

Protected Methods

protected void onLooperPrepared ()

Added in API level 1

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