【Java】使用stream()串行和并行流，代替for循环一行写完

简而言之，就是input.stream() + 具体操作 + collect(Collectors.toList())

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

public class streamLearn {
    public static List<String> removeEmpty(List<String> input) {
        List<String> output = input.stream().filter(string -> !string.isEmpty()).collect(Collectors.toList());
        return output;
    }

    public static List<String> removalDuplicate(List<String> input) {
        List<String> output = input.stream().distinct().collect(Collectors.toList());
        return output;
    }

    public static List<Integer> calculate(List<Integer> input) {
        List<Integer> output = input.stream().map(i -> i*i).collect(Collectors.toList());
        return output;
    }

    public static Long count(List<Integer> input) {
        Long output = input.stream().count();
        return output;
    }

    public static Long countParallel(List<Integer> input) {
        Long output = input.parallelStream().count();
        return output;
    }

    public static void main(String[] args) throws InterruptedException {
        System.out.println(removeEmpty(Arrays.asList("a", "", "b", "c")));
        System.out.println(removalDuplicate(Arrays.asList("a", "a", "b", "c")));
        System.out.println(calculate(Arrays.asList(1,2,3,4,5)));
        System.out.println(count(Collections.nCopies(100, 1)));
        System.out.println(countParallel(Collections.nCopies(100, 1)));
    }
}

//输出如下：
//[a, b, c]
//[a, b, c]
//[1, 4, 9, 16, 25]
//100
//100
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
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46

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