import java.io.ByteArrayInputStream;        import java.io.ByteArrayOutputStream;        import java.io.IOException;        import java.io.UnsupportedEncodingException;        import java.util.zip.GZIPInputStream;        import java.util.zip.GZIPOutputStream;        import android.util.Base64;                public class EncryptUtil {                        private static final int BUFFER_SIZE = 1024;                    /**            * BASE64 加密            * @param str            * @return            */            public static  String encryptBASE64(String str) {                if (str == null || str.length() == 0) {                    return null;                }                try {                    byte[] encode = str.getBytes("UTF-8");                    // base64 加密                    return new String(Base64.encode(encode, 0, encode.length, Base64.DEFAULT), "UTF-8");                        } catch (UnsupportedEncodingException e) {                    e.printStackTrace();                }                        return null;            }                        /**            * BASE64 解密            * @param str            * @return            */            public static  String decryptBASE64(String str) {                if (str == null || str.length() == 0) {                    return null;                }                try {                    byte[] encode = str.getBytes("UTF-8");                    // base64 解密                    return new String(Base64.decode(encode, 0, encode.length, Base64.DEFAULT), "UTF-8");                        } catch (UnsupportedEncodingException e) {                    e.printStackTrace();                }                        return null;            }                        /**            * GZIP 加密            *             * @param str            * @return            */            public static  byte[] encryptGZIP(String str) {                if (str == null || str.length() == 0) {                    return null;                }                        try {                    // gzip压缩                    ByteArrayOutputStream baos = new ByteArrayOutputStream();                    GZIPOutputStream gzip = new GZIPOutputStream(baos);                    gzip.write(str.getBytes("UTF-8"));                            gzip.close();                            byte[] encode = baos.toByteArray();                            baos.flush();                    baos.close();                            // base64 加密                    return encode;        //          return new String(encode, "UTF-8");                        } catch (UnsupportedEncodingException e) {                    e.printStackTrace();                } catch (IOException e) {                    e.printStackTrace();                }                        return null;            }                        /**            * GZIP 解密            *             * @param str            * @return            */            public static  String decryptGZIP(String str) {                if (str == null || str.length() == 0) {                    return null;                }                        try {                                        byte[] decode = str.getBytes("UTF-8");                                        //gzip 解压缩                    ByteArrayInputStream bais = new ByteArrayInputStream(decode);                    GZIPInputStream gzip = new GZIPInputStream(bais);                            byte[] buf = new byte[BUFFER_SIZE];                    int len = 0;                                        ByteArrayOutputStream baos = new ByteArrayOutputStream();                                        while((len=gzip.read(buf, 0, BUFFER_SIZE))!=-1){                         baos.write(buf, 0, len);                    }                    gzip.close();                    baos.flush();                                        decode = baos.toByteArray();                                        baos.close();                            return new String(decode, "UTF-8");                        } catch (UnsupportedEncodingException e) {                    e.printStackTrace();                } catch (IOException e) {                    e.printStackTrace();                }                        return null;            }                        /**            * 十六进制字符串 转换为 byte[]            *             * @param hexString            *            the hex string            * @return byte[]            */            public static byte[] hexStringToBytes(String hexString) {                if (hexString == null || hexString.equals("")) {                    return null;                }                int length = hexString.length() / 2;                char[] hexChars = hexString.toCharArray();                byte[] d = new byte[length];                for (int i = 0; i < length; i++) {                    int pos = i * 2;                    d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));                }                return d;            }                    /**            * Convert char to byte            *             * @param c            *            char            * @return byte            */            private static byte charToByte(char c) {                return (byte) "0123456789abcdef".indexOf(c);                // return (byte) "0123456789ABCDEF".indexOf(c);            }                    /**            * byte[] 转换为 十六进制字符串            *             * @param src            * @return            */            public static String bytesToHexString(byte[] src) {                StringBuilder stringBuilder = new StringBuilder("");                        if (src == null || src.length <= 0) {                    return null;                }                        for (int i = 0; i < src.length; i++) {                    int v = src[i] & 0xFF;                    String hv = Integer.toHexString(v);                    if (hv.length() < 2) {                        stringBuilder.append(0);                    }                    stringBuilder.append(hv);                }                return stringBuilder.toString();            }        }