如何在Java中将文件指针重置为文件的开头？ [英] How Can I Reset The File Pointer to the Beginning of the File in Java?

问题描述

我正在用Java编写一个程序，要求我比较2个文件中的数据。我必须检查文件1中的每一行对文件2的每一行，如果找到匹配，则将它们写入第三个文件。在我读到文件2的末尾之后，如何将指针重置为文件的开头？

I am writing a program in Java that requires me to compare the data in 2 files. I have to check each line from file 1 against each line of file 2 and if I find a match write them to a third file. After I read to the end of file 2, how do I reset the pointer to the beginning of the file?

public class FiFo {
    public static void main(String[] args) 
    {
        FileReader file1=new FileReader("d:\\testfiles\\FILE1.txt");
        FileReader file2=new FileReader("d:\\testfiles\\FILE2.txt");
        try{
            String s1,s2;
            while((s1=file1.data.readLine())!=null){
                System.out.println("s1: "+s1);
                while((s2=file2.data.readLine())!=null){
                    System.out.println("s2: "+s2);
                }
            }
            file1.closeFile();
            file2.closeFile();
        }catch (IOException e) {
            e.printStackTrace();
        }
    }
}

class FileReader {
    BufferedReader data;
    DataInputStream in;

    public FileReader(String fileName)
    {
        try{
            FileInputStream fstream = new FileInputStream(fileName);
            data = new BufferedReader(new InputStreamReader(fstream));
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    } 

    public void closeFile()
    {
        try{
            in.close();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}

推荐答案

我相信 RandomAccessFile 就是您所需要的。它包含： RandomAccessFile＃seek 和 RandomAccessFile＃getFilePointer 。

rewind（）是 seek（0）

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