直接上代码：

package com.epic.crm.utils;

import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class LambdaUtils {

    public static void main(String[] args) {
        List<String> strings = Arrays.asList("test", "hello", "world", "java");
        strings.forEach(s -> System.out.println(s));

        System.out.println("--------------------");
        List<String> collect = strings.stream().filter(s -> s.length() > 4).collect(Collectors.toList());
        collect.forEach(s -> System.out.println(s));

        System.out.println("--------------------");
        List<String> collect1 = strings.stream().map(s -> s.toUpperCase()).collect(Collectors.toList());
        collect1.forEach(s -> System.out.println(s));

        System.out.println("--------------------");
        List<String> collect2 = strings.stream().sorted().collect(Collectors.toList());
        collect2.forEach(s -> System.out.println(s));


        System.out.println("--------------------");
        boolean test = strings.stream().anyMatch(s -> s.equals("test"));
        System.out.println(test);

        System.out.println("--------------------");
        List<Integer> list = Arrays.asList(1, 2, 3, 4, 5);
        int sum = list.stream().reduce(0, (a, b) -> a + b);
        System.out.println(sum);

    }
}