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
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | 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(); } } } |
方法一,继承自Thread
1 2 3 4 5 6 7 8 9 | public class ThreadExtendsThread extends Thread { private int i; @Override public void run() { for (; i < 100 ; i++) { System.out.println(getName() + " " + i); } } } |
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
1 2 3 4 5 6 7 8 9 | public class ThreadImplementsRunnable implements Runnable { private int i; @Override public void run() { for (; i < 100 ; i++){ System.out.println(Thread.currentThread().getName() + " " + i); } } } |
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
1 2 3 4 5 6 7 8 9 10 11 12 13 | 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; } } |
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。