Java创建线程的四种实现方式

1.继承Thread类
2.实现Runnable接口
3.实现Callable接口，通过FutureTask包装器来创建线程package cn.sh;

import java.util.concurrent.Callable;

public class MyCallableThread implements Callable<Integer> {
@Override
public Integer call() throws Exception {
int count = 0;
for (int i = 1; i <= 10; i++) {
count += i;
System.out.println("count=="+count);
}
return count;
}

}

执行测试类：

public class MyTestCallable {
public static void main(String[] args) {
MyCallableThread mThread = new MyCallableThread();

// 执行Callable方式，需要FutureTask实现类的支持，用于接收运算结果
// FutureTask<Integer>是一个包装器
FutureTask<Integer> oneTask = new FutureTask<Integer>(mThread);

//由FutureTask<Integer>创建一个Thread对象：
Thread oneThread = new Thread(oneTask);
oneThread.start();

// 接收线程运算后的结果
Integer sum =0;
try {
// 等所有线程执行完，获取值，因此FutureTask 可用于闭锁
sum = oneTask.get();
System.out.println("-----------------------------");
System.out.println("sum = "+sum);
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
}
}

运行结果：count==1
count==3
count==6
count==10
count==15
count==21
count==28
count==36
count==45
count==55
Thread Name=main
sum = 55
4.使用线程池（ExecutorService）创建线程，代码实例（rt.jar中）：package cn.sh;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;

public class MyTestCallable {
public static void main(String[] args) {
MyCallableThread mThread = new MyCallableThread();

// 执行Callable方式，需要FutureTask实现类的支持，用于接收运算结果
// FutureTask<Integer>是一个包装器
FutureTask<Integer> oneTask = new FutureTask<Integer>(mThread);

//由FutureTask<Integer>创建一个Thread对象：
Thread oneThread = new Thread(oneTask);
oneThread.start();

// 接收线程运算后的结果
Integer sum =0;
try {
// 等所有线程执行完，获取执行结果，因此FutureTask可用于闭锁
sum = oneTask.get();
System.out.println("Thread Name="+Thread.currentThread().getName());
System.out.println("sum = "+sum);
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
}
}