java - 如何将多个文件中的数据合并到一个缓冲区中？

Question

我想使用多个文件中的数据创建一个流。我怎样才能做到呢？有我的java类(class)。或者也许我不应该使用 BufferReader 而应该使用其他方式？谢谢!!

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.stream.Stream;

public class BuffReader {

public static void main(String[] args) throws FileNotFoundException {
    File file1 = new File("src/page_1.txt");
    File file2 = new File("src/page_2.txt");
    File file3 = new File("src/page_3.txt");
    BufferedReader bufferedReader = new BufferedReader(new FileReader(file1));

    //*** I'd like get one bufferedReader with file1 + file2 + file3.

    Stream<String> stream = bufferedReader.lines(); // get Stream
    stream.forEach(e -> System.out.println(e)); // Working with Stream
}
}

Answer 1

您可以从 BufferedReader 为每个文件创建一个 Stream，将它们组合成一个流，然后使用 Stream#flatMap方法来创建一个由所有这些串联而成的流。

import java.util.function.Function;
import java.util.stream.Stream;

public class CombinedStreams
{
    public static void main(String[] args)
    {
        Stream<String> stream0 = Stream.of("line0", "line1");
        Stream<String> stream1 = Stream.of("line2", "line3");
        Stream<String> stream2 = Stream.of("line4", "line5");

        Stream<String> stream = Stream.of(stream0, stream1, stream2)
            .flatMap(Function.identity());

        stream.forEach(e -> System.out.println(e)); 
    }
}

(感谢diesieben07提出的改进建议!)