java - 为什么我会出现 java.io.EOFException？

Question

我有以下任务: 给定以单个 long 开头的文件，该文件告诉您同一文件中单个 int 数据的偏移量，请编写一个获取 int 数据的类。

try {
        long dataPosition = 0;
        int data = 0;
            RandomAccessFile raf = new RandomAccessFile("datafile.txt", "r");

        //Get the position of the data to read.
        dataPosition = raf.readLong();

        //Go to that position.
        raf.seek(dataPosition);

        //Read the data.
        data = raf.readInt();
        raf.close();

        //Tell the world.
        System.out.println("The data is: " + data);

    } catch (FileNotFoundException e) {
        System.err.println("This shouldn't happen: " + e);
    } catch (IOException e) {
        System.err.println("Writing error: " + e);
    }
    }

Answer 1

我认为问题出在这里:

dataPosition = raf.readLong();

您应该从控制台读取位置，而不是从文件中读取位置。

改用这个:

Scanner scr=new Scanner(System.in);
dataPosition = scr.nextLong();

完整代码:

try {
        long dataPosition = 0;
        int data = 0;
        RandomAccessFile raf = new RandomAccessFile("datafile", "r");

        //Get the position of the data to read.
        Scanner scr=new Scanner(System.in);
        dataPosition = scr.nextLong();

        //Go to that position.
        raf.seek(dataPosition);

        //Read the data.
        data = raf.readInt();
        raf.close();

        //Tell the world.
        System.out.println("The data is: " + data);

    } catch (FileNotFoundException e) {
        System.err.println("This shouldn't happen: " + e);
    } catch (IOException e) {
        System.err.println("Writing error: " + e);
    }
    }