In Java, you can create a new thread by extending the Thread class or by implementing the Runnable interface. Here are examples of both methods:

1. Extending the Thread class:

public class MyThread extends Thread {
    public void run() {
        // code to be executed in the new thread
    }
}

// create a new thread and start it
MyThread thread = new MyThread();
thread.start();

In this example, we define a new class called MyThread that extends the Thread class. We override the run() method to define the code that will be executed in the new thread. We then create a new instance of MyThread and call the start() method to start the new thread.

2. Implementing the Runnable interface:

public class MyRunnable implements Runnable {
    public void run() {
        // code to be executed in the new thread
    }
}

// create a new thread and start it
Thread thread = new Thread(new MyRunnable());
thread.start();

In this example, we define a new class called MyRunnable that implements the Runnable interface. We override the run() method to define the code that will be executed in the new thread. We then create a new instance of MyRunnable and pass it as an argument to the Thread constructor. We then call the start() method to start the new thread.

Note that in both examples, we call the start() method to start the new thread. This method will create a new thread of execution and call the run() method to execute the code in the new thread. It's important to note that you should not call the run() method directly, as this will execute the code in the same thread as the caller, rather than in a new thread.