/*

* Copyright 2021 tu.cn All right reserved. This software is the

* confidential and proprietary information of tu.cn ("Confidential

* Information"). You shall not disclose such Confidential Information and shall

* use it only in accordance with the terms of the license agreement you entered

* into with Tu.cn

*/

package com.ariix.java8.lambda;

import org.junit.Test;

import java.util.ArrayList;

import java.util.List;

import java.util.Random;

import java.util.function.Consumer;

import java.util.function.Function;

import java.util.function.Predicate;

import java.util.function.Supplier;

/**

* Java8 内置的四大函数是接口

* <p>

* 1. Consumer<T> 消费型接口

* void accept(T t)

* 2. Supplier<T> 供给型接口

* T get();

* <p>

* 3.Function<T,R> 函数式接口

* R apply(T t)

* 4. Predicate<T> 断言型接口

* boolean test(T t);

*/

public class TestLambda4 {

//Consumer<T> 消费型接口

@Test

public void test() {

happy(100000d, x -> System.out.println("购物 花了" + x + "元"));

}

public void happy(double money, Consumer<Double> consumer) {

consumer.accept(money);

}

public List<Integer> getNumList(int number, Supplier<Integer> supplier) {

List<Integer> list = new ArrayList<>();

for (int i = 0; i < number; i++) {

list.add(supplier.get());

}

return list;

}

// * 2. Supplier<T> 供给型接口

@Test

public void test2() {

Random random = new Random();

List<Integer> numbers = getNumList(20, () -> {

return random.nextInt(100);

});

System.out.println(numbers);

}

// * 3.Function<T,R> 函数式接口

public Integer strHandler(String str, Function<String, Integer> function) {

return function.apply(str);

}

@Test

public void test3() {

Integer length = strHandler("aaaaaaaaaaaa", x -> x.length());

System.out.println(length);

}

// * 4. Predicate<T> 断言型接口

public List<String> filterStr(List<String> list, Predicate<String> predicate) {

List<String> resultList = new ArrayList<>();

for (String s : list) {

if (predicate.test(s)) {

resultList.add(s);

}

}

return resultList;

}

@Test

public void testPredicate() {

List<String> list = new ArrayList<>();

list.add("happy");

list.add("ajiyy");

list.add("jp");

List<String> filterList = filterStr(list, x -> x.contains("a"));

System.out.println(filterList);

}

}