本文实例为大家分享了Java实现多线程的三种方式,供大家参考,具体内容如下
- import java.util.concurrent.Callable;
- import java.util.concurrent.FutureTask;
- public class Main {
- public static void main(String[] args) {
- //方法一:继承Thread
- int i = 0;
- // for(; i < 100; i++){
- // System.out.println(Thread.currentThread().getName() + " " + i);
- // if (i == 5) {
- // ThreadExtendsThread threadExtendsThread = new ThreadExtendsThread();
- // threadExtendsThread.start();
- // }
- // }
-
- //方法二:实现Runnable
- // for(i = 0; i < 100; i++){
- // System.out.println(Thread.currentThread().getName() + " " + i);
- // if (i == 5) {
- // Runnable runnable = new ThreadImplementsRunnable();
- // new Thread(runnable).start();
- // new Thread(runnable).start();
- // }
- // }
- //方法三:实现Callable接口
- Callable<Integer> callable = new ThreadImplementsCallable();
- FutureTask<Integer> futureTask = new FutureTask<>(callable);
- for(i = 0; i < 100; i++){
- System.out.println(Thread.currentThread().getName() + " " + i);
- if (i == 5) {
- new Thread(futureTask).start();
- new Thread(futureTask).start();
- }
- }
- try {
- System.out.println("futureTask ruturn: " + futureTask.get());
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- }
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方法一,继承自Thread
- public class ThreadExtendsThread extends Thread {
- private int i;
- @Override
- public void run() {
- for(; i < 100; i++) {
- System.out.println(getName() + " " + i);
- }
- }
- }
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run方法为线程执行体,ThreadExtendsThread对象即为线程对象。
方法二,实现Runnable接口
- public class ThreadImplementsRunnable implements Runnable {
- private int i;
- @Override
- public void run() {
- for(; i < 100; i++){
- System.out.println(Thread.currentThread().getName() + " " + i);
- }
- }
- }
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run方法为线程执行体,使用时New一个Thread对象,Runnable对象作为target传递给Thread对象。且同一个Runnable对象可作为多个Thread的target,这些线程均共享Runnable对象的实例变量。
方法三,实现Callable接口
- import java.util.concurrent.Callable;
- public class ThreadImplementsCallable implements Callable<Integer> {
- private int i;
-
- @Override
- public Integer call() throws Exception {
- for(; i < 100; i++){
- System.out.println(Thread.currentThread().getName() + " " + i);
- }
- return i;
- }
- }
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Callable接口类似于Runnable接口,但比对方强大,线程执行体为call方法,该方法具有返回值和可抛出异常。使用时将Callable对象包装为FutureTask对象,通过泛型指定返回值类型。可稍候调用FutureTask的get方法取回执行结果。
以上就是本文的全部内容,希望对大家的学习有所帮助。 |