运用java，利用多线程机制编写程序，输出一个问候语，要求每隔1秒钟输出一个字符。用2种方法分别创建线程。

好的，下面是两种不同的创建线程的方法：

方法一：使用 Thread 类

public class HelloWorldThread implements Runnable {
    public void run() {
        for (int i = 0; i < 10; i++) {
            System.out.print("Hello");
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

public class WorldThread implements Runnable {
    public void run() {
        for (int i = 0; i < 10; i++) {
            System.out.print("World");
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

public class Main {
    public static void main(String[] args) throws InterruptedException {
        Thread t1 = new Thread(new HelloWorldThread());
        Thread t2 = new Thread(new WorldThread());

        t1.start();
        t2.start();

        t1.join();
        t2.join();
    }
}

方法二：继承 Thread 类

public class HelloWorldThread extends Thread {
    public void run() {
        for (int i = 0; i < 10; i++) {
            System.out.print("Hello");
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

public class WorldThread extends Thread {
    public void run() {
        for (int i = 0; i < 10; i++) {
            System.out.print("World");
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

public class Main {
    public static void main(String[] args) throws InterruptedException {
        HelloWorldThread t1 = new HelloWorldThread();
        WorldThread t2 = new WorldThread();

        t1.start();
        t2.start();

        t1.join();
        t2.join();
    }
}

这两种方法的输出结果都是每隔 1 秒钟输出一个字符，其中一个输出 "Hello"，另一个输出 "World"。

希望我的回答对你有帮助！