Lambda 函数式接口 Supplier

 

 

 

 

 

 

 

@FunctionalInterface
public interface MyFun {
    void method();
}

public class MyFunImpl implements MyFun {
    @Override
    public void method() {
        System.out.println("impl method .");
    }
}


public class FunDemo {
    public static void main(String[] args) {
        show(new MyFunImpl());
        show(new MyFun() {
            @Override
            public void method() {
                System.out.println("override interface method .");
            }
        });
        show(() -> System.out.println("lambda method ."));
    }

    private static void show(MyFun myFun) {
        myFun.method();
    }
}

 

 

 

 

 

 

@FunctionalInterface
public interface MessageBuileder {
    String message();
}

public class LogDemo {
    public static void main(String[] args) {
        String mes1 = "hello ";
        String mes2 = "java ";
        String mes3 = "world ";
        showInfo(1, () -> mes1 + mes2 + mes3);
        showInfo(2, () -> {
            System.out.println("!=1");
            return mes1 + mes2 + mes3;
        });
    }

    private static void showInfo(int level, MessageBuileder m) {
        if (level == 1) {
            System.out.println(m.message());
        }
    }
}

 

 

 

 

public class RunableDemo {
    public static void main(String[] args) {
        startThead(new Runnable() {
            @Override
            public void run() {
                System.out.println(Thread.currentThread().getName() + " override run .");
            }
        });
        startThead(() -> System.out.println(Thread.currentThread().getName() + " lambda run ."));
    }

    private static void startThead(Runnable run) {
        new Thread(run).start();
    }
}