Lambda表达式-Java

package com.sxt.thread;
/**
 * Lambda表达式 简化线程(用一次)的使用
 *
 */
public class LambdaThread {
    //静态内部类
    static class Test implements Runnable{
        public void run() {
            for(int i=0;i<20;i++) {
                System.out.println("一边听歌");
            }
        }
    }
    public static void main(String[] args) {
        //new Thread(new Test()).start();        

        //局部内部类
        class Test2 implements Runnable{
            public void run() {
                for(int i=0;i<20;i++) {
                    System.out.println("一边听歌");
                }
            }
        }
        new Thread(new Test2()).start();

        //匿名内部类 必须借助接口或者父类
        new Thread(new Runnable() {
            public void run() {
                for(int i=0;i<20;i++) {
                    System.out.println("一边听歌");
                }
            }
        }).start();

        //jdk8 简化  lambda表达式
        new Thread(()-> {
                for(int i=0;i<20;i++) {
                    System.out.println("一边听歌");
                }
            }
        ).start();

    }

}

package com.sxt.thread;
/**
 * lambda推导
 *
 *
 */
public class LambdaTest01 {
    //内部类
    static class Like2 implements ILike{
        public void lambda() {
            System.out.println("i like lambda2 ");
        }

    }
    public static void main(String[] args) {
        ILike like = new Like();
        like.lambda();

        like = new Like2();
        like.lambda();

        class Like3 implements ILike{
            public void lambda() {
                System.out.println("i like lambda3 ");
            }

        }

        like = new Like3();
        like.lambda();
        //匿名内部类
        like = new ILike() {
            public void lambda() {
                System.out.println("i like lambda4 ");
            }
        };
        like.lambda();
        //lambda
        like = ()-> {
            System.out.println("i like lambda5 ");
        };
        like.lambda();

        /*
         *lambda推导必须存在类型
        ()-> {
            System.out.println("i like lambda5 ");
        }.lambda();
        */
    }
}
interface ILike{
    void lambda();
}
//外部类
class Like implements ILike{

    @Override
    public void lambda() {
        System.out.println("i like lambda ");
    }

}

package com.sxt.thread;
/**
 * lambda推导 +参数
 *
 *
 */
public class LambdaTest02 {

    public static void main(String[] args) {
        ILove love =(int a) -> {
            System.out.println("i like lambda -->"+a);
        };

        love.lambda(100);

        //简化
        love =(a) -> {
            System.out.println("i like lambda -->"+a);
        };

        love.lambda(50);

        love =a -> {
            System.out.println("i like lambda -->"+a);
        };

        love.lambda(5);

        love =a ->System.out.println("i like lambda -->"+a);
        love.lambda(0);

    }
}
interface ILove{
    void lambda(int a);
}
//外部类
class Love implements ILove{

    @Override
    public void lambda(int a) {
        System.out.println("i like lambda -->"+a);
    }

}

package com.sxt.thread;
/**
 * lambda推导 +参数+返回值
 *
 *
 */
public class LambdaTest03 {

    public static void main(String[] args) {
        IInterest interest = (int a,int c)-> {
            System.out.println("i like lambda -->"+(a+c));
            return a+c;
        };
        interest.lambda(100,200);

        interest = (a,c)-> {
            System.out.println("i like lambda -->"+(a+c));
            return a+c;
        };

        interest.lambda(200,200);

        interest = (a,c)-> {
            return a+c;
        };

        interest = (a,c)-> a+c;

        interest = (a,c)-> 100;

        System.out.println(interest.lambda(10, 20));
    }
}
interface IInterest{
    int lambda(int a,int b);
}
//外部类
class Interest implements IInterest{

    @Override
    public int lambda(int a,int c) {
        System.out.println("i like lambda -->"+(a+c));
        return a+c;
    }

}

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总的来说，就是

1.（params）->expression

2.（params）->statement

3.（params）->{多行statements}

原文地址：https://www.cnblogs.com/nihaoya-czw/p/10352502.html