为什么GZip算法的结果在Android和.Net中不相同？

Question

为什么GZip算法的结果在Android和.Net中不相同？

我在android中的代码:

    public static String compressString(String str) {

    String str1 = null;
    ByteArrayOutputStream bos = null;
    try {
        bos = new ByteArrayOutputStream();
        BufferedOutputStream dest = null;

        byte b[] = str.getBytes();
        GZIPOutputStream gz = new GZIPOutputStream(bos, b.length);
        gz.write(b, 0, b.length);
        bos.close();
        gz.close();

    } catch (Exception e) {
        System.out.println(e);
        e.printStackTrace();
    }
    byte b1[] = bos.toByteArray();
    return Base64.encode(b1);
}

我在.Net WebService中的代码:

    public static string compressString(string text)
{
    byte[] buffer = Encoding.UTF8.GetBytes(text);
    MemoryStream ms = new MemoryStream();
    using (GZipStream zip = new GZipStream(ms, CompressionMode.Compress, true))
    {
        zip.Write(buffer, 0, buffer.Length);
    }

    ms.Position = 0;
    MemoryStream outStream = new MemoryStream();

    byte[] compressed = new byte[ms.Length];
    ms.Read(compressed, 0, compressed.Length);

    byte[] gzBuffer = new byte[compressed.Length + 4];
    System.Buffer.BlockCopy(compressed, 0, gzBuffer, 4, compressed.Length);
    System.Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gzBuffer, 0, 4);
    return Convert.ToBase64String(gzBuffer);
}

在android中:

compressString("hello"); -> "H4sIAAAAAAAAAMtIzcnJBwCGphA2BQAAAA=="

在.Net:

compressString("hello"); -> "BQAAAB+LCAAAAAAABADtvQdgHEmWJSYvbcp7f0r1StfgdKEIgGATJNiQQBDswYjN5pLsHWlHIymrKoHKZVZlXWYWQMztnbz33nvvvffee++997o7nU4n99//P1xmZAFs9s5K2smeIYCqyB8/fnwfPyLmeVlW/w+GphA2BQAAAA=="

有趣的是,当我在android中使用Decompress方法解压缩.Net compressString方法的结果时,它正确返回原始字符串,但是当我解压缩android compressedString方法的结果时出错.

Android解压缩方法:

    public static String Decompress(String zipText) throws IOException {
    int size = 0;
    byte[] gzipBuff = Base64.decode(zipText);

    ByteArrayInputStream memstream = new ByteArrayInputStream(gzipBuff, 4,
            gzipBuff.length - 4);
    GZIPInputStream gzin = new GZIPInputStream(memstream);

    final int buffSize = 8192;
    byte[] tempBuffer = new byte[buffSize];
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    while ((size = gzin.read(tempBuffer, 0, buffSize)) != -1) {
        baos.write(tempBuffer, 0, size);
    }
    byte[] buffer = baos.toByteArray();
    baos.close();

    return new String(buffer, "UTF-8");
}

我认为Android compressString方法中存在错误.有谁能够帮我？

Answer 1

根据这个答案，我有4种方法。Android 和.net 压缩和解压缩方法。除一种情况外，这些方法彼此兼容。