霍夫曼编码文件保存

Question

I wrote a program that uses huffman coding to take a .txt file and compress it. The program takes the compressed code and saves it as a .hzip file. The code works fine until I try to compress and save a file that contains a new line character. This is my code to save the file:

private void codeToFile() {

    String code = "";
    char letter;

    String fileName = this.encodeFileName.replace(".txt", ".hzip");

    FileOutputStream byteWriter = null;
    FileInputStream reader = null;
    try {

        byteWriter = new FileOutputStream(fileName);
        reader = new FileInputStream(this.encodeFileName);

        while (reader.available() > 0) {
            letter = (char) reader.read();

            code += hCode.get(letter);

            if (code.length() > 7) {
                int c = Integer.parseInt(code.substring(0, 8), 2)
                        + Byte.MIN_VALUE;
                byteWriter.write((byte) c);
                code = code.substring(8);
            }
        }

        if (code.length() > 0 && code.length() <= 7) {
            code += "0000000";
            int c = Integer.parseInt(code.substring(0, 8), 2)
                    + Byte.MIN_VALUE;
            byteWriter.write((byte) c);
        }
        byteWriter.close();

    } catch (IOException ex) {
        ex.printStackTrace();
    }
    System.out.println("===============================");
    System.out.println("File Created: " + fileName);

} 

My error always comes up on this line:

int c = Integer.parseInt(code.substring(0, 8), 2)
                        + Byte.MIN_VALUE;

The specific error I am getting is: Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "110001nu". I don't understand why a new line character is causing this problem. Any help would be much appreciated.

Answer 1

也许你hCode地图不包含新行“信”的条目，所以hCode.get(letter)返回“空”，前两个字母，其中你得到code.substring(0, 8)