MessageQueue 相关概念

/**
 * Implements a thread-local storage, that is, a variable for which each thread
 * has its own value. All threads share the same {
@code ThreadLocal} object,
 * but each sees a different value when accessing it, and changes made by one
 * thread do not affect the other threads. The implementation supports
 * {
@code null} values.
 *
 *
@see java.lang.Thread
 *
@author Bob Lee
 */
public class ThreadLocal<T>

/**
  * Class used to run a message loop for a thread.  Threads by default do
  * not have a message loop associated with them; to create one, call
  * {
@link #prepare} in the thread that is to run the loop, and then
  * {
@link #loop} to have it process messages until the loop is stopped.

public final class Looper 

/**
 *
 * Defines a message containing a description and arbitrary data object that can be
 * sent to a {
@link Handler}.  This object contains two extra int fields and an
 * extra object field that allow you to not do allocations in many cases. 
 *
 *
While the constructor of Message is public, the best way to get
 * one of these is to call {
@link #obtain Message.obtain()} or one of the
 * {
@link Handler#obtainMessage Handler.obtainMessage()} methods, which will pull
 * them from a pool of recycled objects.
</p>
 */
public final class Message implements Parcelable

/**
 * Low-level class holding the list of messages to be dispatched by a
 * {
@link Looper}.  Messages are not added directly to a MessageQueue,
 * but rather through {
@link Handler} objects associated with the Looper.
 *
 *
<p>You can retrieve the MessageQueue for the current thread with
 * {
@link Looper#myQueue() Looper.myQueue()}.
 */
public final class MessageQueue

/**
 * A Handler allows you to send and process {
@link Message} and Runnable
 * objects associated with a thread's {
@link MessageQueue}.  Each Handler
 * instance is associated with a single thread and that thread's message
 * queue.  When you create a new Handler, it is bound to the thread /
 * message queue of the thread that is creating it -- from that point on,
 * it will deliver messages and runnables to that message queue and execute
 * them as they come out of the message queue.

public class Handler

原文地址:https://www.cnblogs.com/feng9exe/p/5726051.html