Added in API level 1

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

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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.

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Inherited Methods

From class java.lang.Thread

static int	activeCount() Returns the number of active `Thread`s in the running `Thread`'s group and its subgroups.
final void	checkAccess() Does nothing.
int	countStackFrames() This method was deprecated in API level 1. The results of this call were never well defined. To make things worse, it would depend on whether the Thread was suspended or not, and suspend was deprecated too.
static Thread	currentThread() Returns the Thread of the caller, that is, the current Thread.
void	destroy() This method was deprecated in API level 1. Not implemented.
static void	dumpStack() Prints to the standard error stream a text representation of the current stack for this Thread.
static int	enumerate(Thread[] threads) Copies an array with all Threads which are in the same ThreadGroup as the receiver - and subgroups - into the array `threads` passed as parameter.
static Map<Thread, StackTraceElement[]>	getAllStackTraces() Returns a map of all the currently live threads to their stack traces.
ClassLoader	getContextClassLoader() Returns the context ClassLoader for this Thread.
static Thread.UncaughtExceptionHandler	getDefaultUncaughtExceptionHandler() Returns the default exception handler that's executed when uncaught exception terminates a thread.
long	getId() Returns the thread's identifier.
final String	getName() Returns the name of the Thread.
final int	getPriority() Returns the priority of the Thread.
StackTraceElement[]	getStackTrace() Returns an array of `StackTraceElement` representing the current thread's stack.
Thread.State	getState() Returns the current state of the Thread.
final ThreadGroup	getThreadGroup() Returns the ThreadGroup to which this Thread belongs.
Thread.UncaughtExceptionHandler	getUncaughtExceptionHandler() Returns the thread's uncaught exception handler.
static boolean	holdsLock(Object object) Indicates whether the current Thread has a monitor lock on the specified object.
void	interrupt() Posts an interrupt request to this `Thread`.
static boolean	interrupted() Returns a `boolean` indicating whether the current Thread ( `currentThread()`) has a pending interrupt request (`true`) or not (`false`).
final boolean	isAlive() Returns `true` if the receiver has already been started and still runs code (hasn't died yet).
final boolean	isDaemon() Tests whether this is a daemon thread.
boolean	isInterrupted() Returns a `boolean` indicating whether the receiver has a pending interrupt request (`true`) or not ( `false`)
final void	join() Blocks the current Thread (`Thread.currentThread()`) until the receiver finishes its execution and dies.
final void	join(long millis, int nanos) Blocks the current Thread (`Thread.currentThread()`) until the receiver finishes its execution and dies or the specified timeout expires, whatever happens first.
final void	join(long millis) Blocks the current Thread (`Thread.currentThread()`) until the receiver finishes its execution and dies or the specified timeout expires, whatever happens first.
final void	resume() This method was deprecated in API level 1. Only useful in conjunction with deprecated method `suspend()`.
void	run() Calls the `run()` method of the Runnable object the receiver holds.
void	setContextClassLoader(ClassLoader cl) Set the context ClassLoader for the receiver.
final void	setDaemon(boolean isDaemon) Marks this thread as a daemon thread.
static void	setDefaultUncaughtExceptionHandler(Thread.UncaughtExceptionHandler handler) Sets the default uncaught exception handler.
final void	setName(String threadName) Sets the name of the Thread.
final void	setPriority(int priority) Sets the priority of this thread.
void	setUncaughtExceptionHandler(Thread.UncaughtExceptionHandler handler) Sets the uncaught exception handler.
static void	sleep(long millis, int nanos) Causes the thread which sent this message to sleep for the given interval of time (given in milliseconds and nanoseconds).
static void	sleep(long time) Causes the thread which sent this message to sleep for the given interval of time (given in milliseconds).
synchronized void	start() Starts the new Thread of execution.
synchronized final void	stop(Throwable throwable) This method was deprecated in API level 1. Stopping a thread in this manner is unsafe and can leave your application and the VM in an unpredictable state.
final void	stop() This method was deprecated in API level 1. Stopping a thread in this manner is unsafe and can leave your application and the VM in an unpredictable state.
final void	suspend() This method was deprecated in API level 1. May cause deadlocks.
String	toString() Returns a string containing a concise, human-readable description of the Thread.
static void	yield() Causes the calling Thread to yield execution time to another Thread that is ready to run.

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

From interface java.lang.Runnable

Public Constructors

public HandlerThread (String name)

Added in API level 1

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

The looper.

public int getThreadId ()

Added in API level 1

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

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

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

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

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.

Results

Interfaces

Classes

Enums

Exceptions

HandlerThread

Class Overview

Summary

Public Constructors

public HandlerThread (String name)

public HandlerThread (String name, int priority)

Parameters

Public Methods

public Looper getLooper ()

Returns

public int getThreadId ()

public boolean quit ()

Returns

See Also

public boolean quitSafely ()

Returns

public void run ()

Protected Methods

protected void onLooperPrepared ()