Lambda范例

参考：https://www.cnblogs.com/haixiang/p/11029639.html

代码

package com.junna.test.lombda;

public class LambdaApp {

    interface MathOperation {
        int operation(int a, int b);
    }

    interface GreetingService {
        void sayMessage(String message);
    }

    private int operate(int a, int b, MathOperation mathOperation) {
        return mathOperation.operation(a, b);
    }

    public static void main(String args[]) {
        LambdaApp tester = new LambdaApp();

        // 类型声明
        MathOperation addition = (int a, int b) -> a + b;

        // 不用类型声明
        MathOperation subtraction = (a, b) -> a - b;

        // 大括号中的返回语句
        MathOperation multiplication = (int a, int b) -> {
            return a * b;
        };

        // 没有大括号及返回语句
        MathOperation division = (int a, int b) -> a / b;

        System.out.println("10 + 5 = " + tester.operate(10, 5, addition));
        System.out.println("10 - 5 = " + tester.operate(10, 5, subtraction));
        System.out.println("10 x 5 = " + tester.operate(10, 5, multiplication));
        System.out.println("10 / 5 = " + tester.operate(10, 5, division));


        // 不用括号
        GreetingService greetService1 = message -> System.out.println("Hello " + message);

        // 用括号
        GreetingService greetService2 = (message) -> System.out.println("Hello " + message);

        greetService1.sayMessage("Runoob");
        greetService2.sayMessage("Google");
    }
}

运行结构

10 + 5 = 15
10 - 5 = 5
10 x 5 = 50
10 / 5 = 2
Hello Runoob
Hello Google