创建流

package com.imooc.zhangxiaoxi.stream;

import org.junit.Test;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.stream.IntStream;
import java.util.stream.Stream;

/**

• 流的四种构建形式
  */
  public class StreamConstructor {

  /**

  • 由数值直接构建流
    */
    @Test
    public void streamFromValue() {
    Stream stream = Stream.of(1, 2, 3, 4, 5);

    stream.forEach(System.out::println);
    }

  /**

  • 通过数组构建流
    */
    @Test
    public void streamFromArray() {
    int[] numbers = {1, 2, 3, 4, 5};

    IntStream stream = Arrays.stream(numbers);
    stream.forEach(System.out::println);
    }

  /**

  • 通过文件生成流

  • @throws IOException
    */
    @Test
    public void streamFromFile() throws IOException {
    // TODO 此处替换为本地文件的地址全路径
    String filePath = "";

    Stream stream = Files.lines(
    Paths.get(filePath));

    stream.forEach(System.out::println);
    }

  /**

  • 通过函数生成流（无限流）
    */
    @Test
    public void streamFromFunction() {

// Stream stream = Stream.iterate(0, n -> n + 2);

    Stream stream = Stream.generate(Math::random);

    stream.limit(100)
            .forEach(System.out::println);

}

}