public static String uncompressString(String str) throws IOException {
    if (str == null ¦¦ str.length() == 0) {
      return str;
    }
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    ByteArrayInputStream in = new ByteArrayInputStream(str
        .getBytes("ISO-8859-1"));
    GZIPInputStream gunzip = new GZIPInputStream(in);
    byte[] buffer = new byte[256];
    int n;
    while ((n = gunzip.read(buffer)) >= 0) {
      out.write(buffer, 0, n);
    }
    // toString()使用平台默认编码，也可以显式的指定如toString("GBK")
    return out.toString();
  }

public static void main(String[] args) throws IOException {
    String a = compressString("China");
    System.out.println(a);
    System.out.println(a.length());
    String b = uncompressString(a);
    System.out.println(b);
}