Java创建线程的5种方式（附代码示例）

在Java中，创建线程有以下五种常见方式：

1. 继承Thread类
2. 实现Runnable接口
3. 使用Callable和Future
4. 使用线程池
5. 使用ForkJoinPool（Java 7 引入）

以下是每种方式的示例代码：

1. 继承Thread类：

public class MyThread extends Thread {
    public void run() {
        System.out.println("Thread is running");
    }
}
 
// 使用
public class Main {
    public static void main(String[] args) {
        MyThread myThread = new MyThread();
        myThread.start();
    }
}

2. 实现Runnable接口：

public class MyRunnable implements Runnable {
    public void run() {
        System.out.println("Runnable is running");
    }
}
 
// 使用
public class Main {
    public static void main(String[] args) {
        MyRunnable myRunnable = new MyRunnable();
        Thread thread = new Thread(myRunnable);
        thread.start();
    }
}

3. 使用Callable和Future（通常与线程池结合使用）：

import java.util.concurrent.*;
 
public class MyCallable implements Callable<String> {
    public String call() throws Exception {
        return "Callable is completed";
    }
}
 
// 使用
public class Main {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        MyCallable myCallable = new MyCallable();
        ExecutorService executorService = Executors.newSingleThreadExecutor();
        Future<String> future = executorService.submit(myCallable);
        System.out.println(future.get());
        executorService.shutdown();
    }
}

4. 使用线程池：

import java.util.concurrent.*;
 
public class MyRunnable implements Runnable {
    public void run() {
        System.out.println("Runnable is running");
    }
}
 
// 使用
public class Main {
    public static void main(String[] args) {
        MyRunnable myRunnable = new MyRunnable();
        ExecutorService executorService = Executors.newFixedThreadPool(10);
        executorService.execute(myRunnable);
        executorService.shutdown();
    }
}

5. 使用ForkJoinPool：

import java.util.concurrent.*;
 
public class MyRecursiveTask extends RecursiveTask<Integer> {
    private static final int THRESHOLD = 10000;
    private int start;
    private int end;
 
    public MyRecursiveTask(int start, int end) {
        this.start = start;
        this.end = end;
    }
 
    protected Integer compute() {
        int sum = 0;
        if (end - start < THRESHOLD) {
            for (int i = start; i < end; i++) {
                sum