步骤如下：
示例代码：
java
public class MyThread extends Thread {
public void run() {
// 新线程的代码
}
}
MyThread thread = new MyThread();
thread.start();
步骤如下：
示例代码：
java
public class MyRunnable implements Runnable {
public void run() {
// 新线程的代码
}
}
MyRunnable myRunnable = new MyRunnable();
Thread thread = new Thread(myRunnable);
thread.start();
步骤如下：
示例代码：
java
Runnable runnable = () -> {
// 新线程的代码
};
Thread thread = new Thread(runnable);
thread.start();