Java8中内置的四大核心函数式接口

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package com.expgiga.Java8;import java.util.ArrayList;import java.util.Arrays;import java.util.List;import java.util.function.Consumer;import java.util.function.Function;import java.util.function.Predicate;import java.util.function.Supplier;/** * Java8内置的四大核心函数式接口 * * 1.Consumer<T>：消费型接口 * void accept(T t); * 2.Supplier<T>：供给型接口 * T get(); * 3.Function<T, R>：函数型接口 * R apply(T t); * 4.Predicate<T>：断言型接口 * boolean test(T t); */public class TestLambda3 {    public static void main(String[] args) {        //Consumer<T>消费型接口        happy(10000, (m) -> System.out.println("Play Game!: " + m + " yuan"));        //Supplier<T>        List<Integer> numList = getNumList(10, () -> (int) (Math.random() * 100));        for (Integer num : numList) {            System.out.println(num);        }        //Function<T, R>函数型接口        String newStr = strHandler("\t\t\t 你牛逼  ", (str) -> str.trim());        System.out.println(newStr);        String subStr = strHandler("我也牛逼，大家都牛逼", (str) -> str.substring(2, 5));        System.out.println(subStr);        //Predicate<T> 断言型接口        List<String> list = Arrays.asList("Hello", "you", "me", "Java", "Scala");        List<String> newlist = filterStr(list, (s) -> s.length() > 3);        for (String str : newlist) {            System.out.println(str);        }    }    private static void happy(double money, Consumer<Double> con) {        con.accept(money);    }    //需求：产生一些整数，并放入集合中    private static List<Integer> getNumList(int num, Supplier<Integer> sup) {        List<Integer> list = new ArrayList<>();        for (int i = 0; i < num; i++) {            Integer n = sup.get();            list.add(n);        }        return list;    }    //需求：用于处理字符串    private static String strHandler(String str, Function<String, String> fun) {        return fun.apply(str);    }    //需求：将满足条件的字符串放入集合中去    private static List<String> filterStr(List<String> list, Predicate<String> predicate) {        List<String> strList = new ArrayList<>();        for (String str : list) {            if (predicate.test(str)) {                strList.add(str);            }        }        return strList;    }}
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