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HandlerThread.javaAPI DocAndroid 5.1 API4898Thu Mar 12 22:22:10 GMT 2015android.os

HandlerThread

public class HandlerThread extends Thread
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.

Fields Summary
int
mPriority
int
mTid
Looper
mLooper
Constructors Summary
public HandlerThread(String name)


       
        super(name);
        mPriority = Process.THREAD_PRIORITY_DEFAULT;
public HandlerThread(String name, int priority)
Constructs a HandlerThread.

param
name
param
priority The priority to run the thread at. The value supplied must be from {@link android.os.Process} and not from java.lang.Thread.

        super(name);
        mPriority = priority;
Methods Summary
public LoopergetLooper()
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.

return
The looper.

        if (!isAlive()) {
            return null;
        }
        
        // If the thread has been started, wait until the looper has been created.
        synchronized (this) {
            while (isAlive() && mLooper == null) {
                try {
                    wait();
                } catch (InterruptedException e) {
                }
            }
        }
        return mLooper;
public intgetThreadId()
Returns the identifier of this thread. See Process.myTid().

        return mTid;
protected voidonLooperPrepared()
Call back method that can be explicitly overridden if needed to execute some setup before Looper loops.
public booleanquit()
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 {@link Handler#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 {@link #quitSafely} instead to ensure that all pending work is completed in an orderly manner.

return
True if the looper looper has been asked to quit or false if the thread had not yet started running.
see
#quitSafely

        Looper looper = getLooper();
        if (looper != null) {
            looper.quit();
            return true;
        }
        return false;
public booleanquitSafely()
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 {@link Handler#sendMessage(Message)} method will return false.

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

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

        Looper looper = getLooper();
        if (looper != null) {
            looper.quitSafely();
            return true;
        }
        return false;
public voidrun()

        mTid = Process.myTid();
        Looper.prepare();
        synchronized (this) {
            mLooper = Looper.myLooper();
            notifyAll();
        }
        Process.setThreadPriority(mPriority);
        onLooperPrepared();
        Looper.loop();
        mTid = -1;