使用synchronized关键字来同步多个线程操作同一个文件

import java.io.FileWriter;
import java.io.IOException;

public class FileSyncExample {
    private static Object file = new Object();

    public static void main(String[] args) throws InterruptedException {
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (file) {
                    try {
                        FileWriter writer = new FileWriter("output.txt", true);
                        writer.write("Hello from thread 1\n");
                        writer.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        });

        Thread t2 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (file) {
                    try {
                        FileWriter writer = new FileWriter("output.txt", true);
                        writer.write("Hello from thread 2\n");
                        writer.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        });

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