Original Java multithreading (i)

It is impossible to read a book without practice. To practice the ~~~~~~ (quote please specify source)

First look at the encyclopedia of the introduction of multithreading

Http://baike.baidu.com/view/65706.htm?fr=aladdin

Java Support for multithreading

Java 3 common ways to create multithreading:

1) inherit the thread class

Rewrite the thread class's Run method, create the thread subclass instance, and start the threads.

For example:

/* * @author [email protected]  Wangxu */public class Treadofextends extends thread{private int i;//rewrite run () method public Voi D run () {for (i=0; i<50; i++) {System.out.println (GetName () + "" + i),////inherit the thread class directly using this to get the current thread}}public static void M Ain (string[] args) {System.out.println (Thread.CurrentThread (). GetName ()); for (int i=0; i<50; i++) {if (i = = 10) {// The start () method is called directly by creating a class object to new Treadofextends (). Start (); New Treadofextends (). Start ();}}}

2) Implement Runnable interface

Rewrite the run () method to create the runnable instance as the target of the thread.

For example:

public class Threadofrun implements Runnable {private int i;//implement the Run () method in the Runnable interface public void Run () {for (i=0; i<50; i+ +) {System.out.println (Thread.CurrentThread (). GetName () + "" + i);//The  current process cannot be obtained through the This keyword by implementing the interface to implement multithreading}}public static void Main (string[] args) {for (int i=0; i<50; i++) {System.out.println (Thread.CurrentThread (). GetName () + "" + I if (i = =) {   Threadofrun tor = new Threadofrun ();   The new thread   (Tor, "Thread 1") will need to be constructed by using thread's constructor method. Start ();   New Thread (Tor, "Thread 2"). Start ();}}}    

3) Java 5 can be used more powerful means-to implement the callable interface

Create and start a new thread using the target of the Futuretask object as the thread object

Import Java.util.concurrent.callable;import Java.util.concurrent.futuretask;public class Threadofcallble implements callable<integer> {                                        //support generic public    integer call () throws Exception {    int i;    for (i=0; i<50; i++) {    System.out.println (Thread.CurrentThread (). GetName () + "" + i);    } Return i;//has return value}public static void Main (string[] args) {//Create callable object threadofcallble TOC = new threadofcallble ();// Wrapping callable objects through futuretask futuretask<integer> ft = new futuretask<integer> (TOC); for (int i=0; i<50; i++) {if (i ==10) {new Thread (ft, "Newthread"). Start ();}} try {//Gets the return value of the new thread System.out.println ("The return value of the child thread:" + ft.get ());} catch (Exception e) {e.printstacktrace ();}}}

Three ways of comparison: the latter two methods are very suitable for multiple same threads to handle the same resource situation, the CPU, code and data can be separated, more consistent with the object-oriented thinking, but also can inherit other classes, so generally adopt the latter two methods.

Thread life cycle: New and ready state--run and block state--thread dead (non-resurrected).

Join thread

When a join method of another thread is called in a program execution, the thread is blocked until the join thread finishes execution.

<pre class= "java" name= "code" >public class Threadofjoin extends Thread {public threadofjoin (String name) {Super ( name);}    public void Run () {for (int i=0; i<50; i++) {System.out.println (GetName ());}} public static void Main (string[] args) {new Threadofjoin ("Newthread"). Start (), for (int i=0; i<50; i++) {if (i = =) {THR Eadofjoin Toj = new Threadofjoin ("Joinedthread"); Toj.start (); try {toj.join ();//The main thread calls the Toj join method and needs to wait for Toj to execute after the main thread is executed} catch (Interruptedexception e) {e.printstacktrace ();}} System.out.println (Thread.CurrentThread (). GetName ());}}}

To be continued: Thread priority, thread synchronization, mutex, Sync lock, deadlock, thread communication.

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Original Java multithreaded Walkthrough (i)