lambda表达式与传统接口函数实现方式对比详解

public class LambdaDemo {
    //函数定义
    public void printSomething(String something) {
        System.out.println(something);
    }
    //通过创建对象调用函数
    public static void main(String[] args) {
        LambdaDemo demo = new LambdaDemo();
        String something = "I am learning Lambda";
        demo.printSomething(something);
    }
}

public class LambdaDemo {
    //抽象功能接口
    interface Printer {
        void print(String val);
    }
    //通过参数传递功能接口
    public void printSomething(String something, Printer printer) {
        printer.print(something);
    }
}

public static void main(String[] args) {
    LambdaDemo demo = new LambdaDemo();
    String something = "I am using a Functional interface";
    //实现Printer接口
    Printer printer = new Printer() {
        @Override
        public void print(String val) {
            //控制台打印
            System.out.println(val);
        }
    };
    demo.printSomething(something, printer);
}

（param1，param2，param3 ...，paramN）-  > {   //代码块；  }

public static void main(String[] args) {
    LambdaDemo demo = new LambdaDemo();
    String something = "I am learning Lambda";
    //实现Printer接口（请关注下面这行lambda表达式代码）
    Printer printer = (String toPrint)->{System.out.println(toPrint);};
    //调用接口打印
    demo.printSomething(something, printer);
}

Printer printer = (String toPrint)->{System.out.println(toPrint);};
//简化：去掉参数类型
Printer printer = (toPrint)->{System.out.println(toPrint);};
//简化：去掉参数括号
Printer printer = toPrint->{System.out.println(toPrint);};
//简化：去掉函数体花括号
Printer printer = toPrint->System.out.println(toPrint);

（）->  System.out.println("anything you wan to print")

public static void main(String[] args) {
    LambdaDemo demo = new LambdaDemo();
    String something="I am Lambda";
    //关注下面的这行代码
    demo.printSomething(something, toPrint -> System.out.println(toPrint));
}