介紹

Java Stream 可以極大提高程式設計師的生產力，讓程式設計師寫出高效率、簡潔的程式碼。

建立流

public class Test {
  public static void main(String[] args) {
    // Array -> Stream
    String[] array = {"wo", "ai", "fei", "ge"};
    Stream<String> stream = Arrays.stream(array);
    Stream<String> stream1 = Stream.of(array);
    // List -> Stream
    List<String> list = Arrays.asList(array);
    Stream<String> stream2 = list.stream();
    // Stream
    Stream.generate(() -> new Random().nextInt()).limit(10);
    Stream.iterate(1, i -> i+1).limit(10);
  }
}
 

操作流

public class Test {
  public static void main(String[] args) {
    // Array -> Stream
    String[] array = {"wo", "ai", "fei", "g_e", "", "g_e"};
    Stream<String> stream = Arrays.stream(array);
    // 過濾空格
    stream.filter(i -> !i.isEmpty())
        .distinct() //去重
        .sorted() //排序
        .map(f -> f.replace("_","")) //處理每個元素
        .forEach(System.out::println);
  }
}