Question

我有一个字节数组，Hex开始（它很大）用这个：

78 9C 9D 5B 4B 6F A4 38 10 FE 2F 9C 19 89 F2 83 47 1F 77 46 7B DA D3 CE 6A 2F A3 08 91 B4 93 B4 96 40 0B E8 64 A2 28 FF 7D A1 B1 3B 2E C0 ED 72 4F 94 E9 04 EA 61 57 7D F5 32 E4 23 7A AB 5E 55 D9 9C 5E A2 5D 01 10 47 55 B3 EF DA C3 BE 7C A8 0F AA 19 A2 DD D0 9D

它以0x789c开头，这是lzma头。

我通过以下方法运行它：

public byte[] decompress(byte[] bytesToDecompress)
    {
        byte[] returnValues = null;

        Inflater inflater = new Inflater();

        int numberOfBytesToDecompress = bytesToDecompress.length;

        inflater.setInput
        (
            bytesToDecompress,
            0,
            numberOfBytesToDecompress
        );

        int bufferSizeInBytes = numberOfBytesToDecompress;

        int numberOfBytesDecompressedSoFar = 0;
        List<Byte> bytesDecompressedSoFar = new ArrayList<Byte>();

        try
        {
            while (inflater.needsInput() == false)
            {
                byte[] bytesDecompressedBuffer = new byte[bufferSizeInBytes];

                int numberOfBytesDecompressedThisTime = inflater.inflate
                (
                    bytesDecompressedBuffer
                );

                numberOfBytesDecompressedSoFar += numberOfBytesDecompressedThisTime;

                for (int b = 0; b < numberOfBytesDecompressedThisTime; b++)
                {
                    bytesDecompressedSoFar.add(bytesDecompressedBuffer[b]);
                }
            }

            returnValues = new byte[bytesDecompressedSoFar.size()];
            for (int b = 0; b < returnValues.length; b++) 
            {
                returnValues[b] = (byte)(bytesDecompressedSoFar.get(b));
            }

        }
        catch (DataFormatException dfe)
        {
            dfe.printStackTrace();
        }

        inflater.end();

        return returnValues;
    }

    public String decompressToString(byte[] bytesToDecompress)
    {   
        byte[] bytesDecompressed = this.decompress
        (
            bytesToDecompress
        );

        String returnValue = null;

        try
        {
            returnValue = new String
            (
                bytesDecompressed,
                0,
                bytesDecompressed.length,
                "UTF-8"
            );  
        }
        catch (UnsupportedEncodingException uee)
        {
            uee.printStackTrace();
        }

        return returnValue;
    }

像这样： System.out.println(decompressToString(jsonDecompressed));

但是我没有打印出任何内容..也没有堆栈跟踪...

为什么会这样？

Answer 1

您的代码已经正确，您只需使用以下问题中的方法将十六进制字符串转换为字节数组：

Convert a string representation of a hex dump to a byte array using Java?

public static byte[] hexStringToByteArray(String s) {
    int len = s.length();
    byte[] data = new byte[len / 2];
    for (int i = 0; i < len; i += 2) {
        data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
                             + Character.digit(s.charAt(i+1), 16));
    }
    return data;
}

然后，您可以将前一个方法与十六进制字符串（不含空格）

一起使用

 public static void main(String[] args) {
    String strData = "789C9D5B4B6FA43810FE2F9C1989F283471F77467BDAD3CE6A2FA30891B493B496400BE864A228FF7DA1B13B2EC0ED724F94E904EA61577DF532E4237AAB5E55D99C5EA25D01104755B3EFDAC3BE7CA80FAA19A2DDD09D";
    byte[] jsonDecompressed = hexStringToByteArray(strData);
    System.out.println(decompressToString(jsonDecompressed));
}

并获得正确的解压缩值：

{"wave_num":911,"android_client":tr

Java解压缩zlib

1 个答案: