8.8 以管道取代循环（Replace Loop with Pipeline）

资料参考：https://mkyong.com/java8/java-8-streams-filter-examples/

动机：简化了循环过程，代码的可读性更强

示例代码：

 1 class Test {
 2     public static void main(String[] args) {
 3         List<String> fruits = Arrays.asList("apple", "orange", "banana");
 4 
 5         // method one 使用循环
 6         List<String> resultsOfLoop = getFilterOutput(fruits, "orange");
 7         for (String result : resultsOfLoop) {
 8             System.out.println(result);
 9         }
10 
11         System.out.println("=================");
12 
13         // method two 使用管道运算
14         List<String> resultsOfPipeline =
15             fruits.stream().filter(fruit -> !"orange".equals(fruit)).collect(Collectors.toList());
16         resultsOfPipeline.forEach(System.out::println);
17     }
18 
19     private static List<String> getFilterOutput(List<String> fruits, @NonNull String filter) {
20         List<String> result = new ArrayList<>();
21         for (String fruit : fruits) {
22             if (!filter.equals(fruit)) {
23                 result.add(fruit);
24             }
25         }
26         return result;
27     }
28 }

运行结果：

1 apple
2 banana
3 =================
4 apple
5 banana