标签：nts run sed ide The 表示 exec 避免 style
多线程的实现三种方式:
1 继承thread类,重写run方法
继承thread方法就可以i调用thread类的start方法,,start方法调用java natvie start0();
这个是调用操作系统的方法,start方法
package com.cxy; class Mythread01 extends Thread{ @Override public void run(){ System.out.println("iii"); }} public class Mythread { public static void main(String[] args) { Mythread01 my = new Mythread01(); my.start(); } }
2 实现runnable接口
接口实现是没有start方法,但是多线程必须采用start方法,所以需要调用new thread(mythread)
再调用start方法.
package com.cxy; import sun.security.krb5.internal.Ticket; class MyThread implements Runnable{ private Integer ticket=10; @Override public void run() { synchronized (this) { for (int i = 0; i < 10; i++) { System.out.println("zhgee" + i); System.out.println(ticket); ticket--; if (ticket<0){ break; } } } } } public class RunnableDemo { public static void main(String[] args) { MyThread myThread=new MyThread(); new Thread(myThread).start(); new Thread(myThread).start(); } }
前两中方法的区别:
thread类是runnable的接口子类,可以有效避免单继承的局限性
runnable接口可以很好的体现数据共享概念
如果继承thread类,那么就可以继承sart方法,runnable接口中,需要构建thread对象调用thread的start方法
3 实现callable接口
package com.cxy; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.FutureTask; class CallableThread implements Callable<String> { private Integer ticket = 10; @Override public String call() throws Exception { synchronized (this) { for (int i = 0; i < 10; i++) { System.out.println("zhgee" + i); System.out.println(ticket); ticket--; if (ticket < 0) { break; } } return "票卖完了"; } } } public class CallableDemo { public static void main(String[] args) throws ExecutionException, InterruptedException { CallableThread callableThread=new CallableThread(); CallableThread callableThread1=new CallableThread(); FutureTask<String> futureTask=new FutureTask(callableThread); FutureTask<String> futureTask1=new FutureTask(callableThread1); new Thread(futureTask).start(); new Thread(futureTask1).start(); System.out.println(futureTask.get()); System.out.println(futureTask1.get()); } }
三个方法都必须调用start方法才可以启动线程
public synchronized void start() { /** * This method is not invoked for the main method thread or "system" * group threads created/set up by the VM. Any new functionality added * to this method in the future may have to also be added to the VM. * * A zero status value corresponds to state "NEW". */ if (threadStatus != 0) throw new IllegalThreadStateException(); /* Notify the group that this thread is about to be started * so that it can be added to the group‘s list of threads * and the group‘s unstarted count can be decremented. */ group.add(this); boolean started = false; try { start0(); started = true; } finally { try { if (!started) { group.threadStartFailed(this); } } catch (Throwable ignore) { /* do nothing. If start0 threw a Throwable then it will be passed up the call stack */ } } } private native void start0();
private native void start0();这个方法是用native修饰,表示调用操作系统的本地方法,所以就需要调用操作系统的方法
标签：nts run sed ide The 表示 exec 避免 style
原文地址：https://www.cnblogs.com/xiufengchen/p/10655846.html
