public class MyThread extends Thread {
    @Override
    public void run() {
        // 线程执行的代码
    }
}
MyThread myThread = new MyThread();
myThread.start();

public class MyRunnable implements Runnable {
    @Override
    public void run() {
        // 线程执行的代码
    }
}
MyRunnable myRunnable = new MyRunnable();
Thread thread = new Thread(myRunnable);
thread.start();

import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;
public class MyCallable implements Callable<Integer> {
    @Override
    public Integer call() throws Exception {
        // 线程执行的代码，返回值
        return 123;
    }
}
                            
MyCallable myCallable = new MyCallable();
FutureTask<Integer> futureTask = new FutureTask<>(myCallable);
Thread thread = new Thread(futureTask);
thread.start();
// 获取结果
Integer result = futureTask.get();

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
ExecutorService executor = Executors.newFixedThreadPool(10);
// 创建包含10个线程的线程池
executor.execute(new MyRunnable());
executor.shutdown(); 
// 关闭线程池