方法引用

public class Main {
    public static void main(String[] args) {
        //匿名内部类
        Runnable runnable = new Runnable() {
            @Override
            public void run() {
                System.out.println("hello world!");
            }
        };

        Thread thread = new Thread(runnable);
        thread.start();
    }
}

需要使用函数式接口的对象的地方可以使用lambda表达式：

public static void main(String[] args) {
    //1.
    Runnable runnable = () -> {
        System.out.println("hello world!");
    };
    
    //2.
    Thread thread = new Thread(() -> {
        System.out.println("hello world!");
    });
    thread.start();
}

有时已经有现成的方法可以完成你想要传递给其他代码的某个动作，此时可以直接将该方法传递：

public class Main {
    public static void main(String[] args) {
        //1.
        Runnable runnable = Main::myRunnable;

        //2.
        Thread thread = new Thread(Main::myRunnable);
        thread.start();
    }

    //静态方法
    public static void myRunnable() {
        System.out.println("hello world!");
    }
}

public class Main {
    public static void main(String[] args) {
        //创建实例
        Main main = new Main();

        //1.
        Runnable runnable = main::myRunnable;

        //2.
        Thread thread = new Thread(main::myRunnable);
        thread.start();
    }

    //非静态方法
    public void myRunnable() {
        System.out.println("hello world!");
    }
}

方法引用

原文：https://www.cnblogs.com/KenBaiCaiDeMiao/p/12861484.html