Question

我有一个功能，旨在将文本文件的内容写入二进制文件。当overwrite为true时，代码工作正常，但是当overwrite为false时，它在第80行停止（oldCount = binaryInput.readInt（）;）并抛出一个空异常。我是Java的新手，所以我可能会做一些明显的事情。这是堆栈跟踪：java.io.EOFException 在java.io.DataInputStream.readInt（未知来源） at java.io.ObjectInputStream $ BlockDataInputStream.readInt（Unknown Source） at java.io.ObjectInputStream.readInt（Unknown Source）在Converter.fromText（Converter.java:80）在Tron_Class.main（Tron_Class.java:19）

    public static int fromText (String textRefference, String binaryRefference, boolean overwrite){

    if(!(new File(binaryRefference).exists()))overwrite = true;
    BufferedReader input;
    ObjectOutputStream output;
    ObjectInputStream binaryInput;
    int count = 0;

    try{
        input = new BufferedReader(new FileReader(textRefference));
        String[] data = null;
        int oldCount = 0;
        if(!overwrite){
            binaryInput = new ObjectInputStream(new FileInputStream(binaryRefference));
            oldCount = binaryInput.readInt();
            data = new String[oldCount];
            int i;
            for(i = 0;i < oldCount; i++){

                data[i] = binaryInput.readUTF();

            }

        }

        output = new 
                ObjectOutputStream(new FileOutputStream(binaryRefference));

        String sentinel = input.readLine();
        String[] data2 = new String[1500];
        while(!sentinel.equalsIgnoreCase("end")){

            System.out.println(sentinel + "   has been recorded");
            data2[count] = sentinel;
            sentinel = input.readLine();
            count++;

        }

        if(!overwrite)count += oldCount;

        output.writeInt(count);

        if(!overwrite){

            int i;
            for(i = 0; i < oldCount;i++){

                output.writeUTF(data[i]);

            }

        }

        int i = 0;
        for(; i < count;i++){

            output.writeUTF(data2[i]);

        }

        output.close();
        input.close();

    }

    catch(Exception e){
        Scanner in = new Scanner(System.in);
        System.out.println(e.getMessage());
        System.out.println("\n hit ENTER to exit.");
        in.nextLine();
        System.exit(0);
    }
    return count;
}

Answer 1

此循环不正确。

    int i = 0;
    for(; i < count;i++){

问题是count是字符串的总数，而不仅仅是此data2数组中的数字。一旦你尝试writeUTF(null)，它就会爆炸。

更简单的解决方案是不首先修改count，而是写

output.writeInt(oldCount + count);

然后上面的循环将有正确的count

WriteInt（）似乎没有运作

1 个答案: