【汉字加密解密】一个16进制，可用于.net与java接口加密、解密

/**
* 得到16进制的GBK编码，转换为汉字
* @param hexStr
* @return
*/
public static String decode(String hexStr){
if( null==hexStr || "".equals(hexStr) || (hexStr.length())%2 != 0 ) {
return null;
}
int byteLength = hexStr.length() / 2;
byte[] bytes=new byte[ byteLength ];
int temp=0;
for(int i=0;i<byteLength;i++) {
temp = hex2Dec(hexStr.charAt(2*i))*16+hex2Dec(hexStr.charAt(2*i+1));
bytes[i]=(byte)( temp<128 ? temp : temp-256 ) ;
}
return new String(bytes);
}
private static String hexString="0123456789ABCDEF";
private static int hex2Dec(char ch){
if(ch == '0')
return 0;
if(ch == '1')
return 1;
if(ch == '2')
return 2;
if(ch == '3')
return 3;
if(ch == '4')
return 4;
if(ch == '5')
return 5;
if(ch == '6')
return 6;
if(ch == '7')
return 7;
if(ch == '8')
return 8;
if(ch == '9')
return 9;
if(ch == 'a')
return 10;
if(ch == 'A')
return 10;
if(ch == 'B')
return 11;
if(ch == 'b')
return 11;
if(ch == 'C')
return 12;
if(ch == 'c')
return 12;
if(ch == 'D')
return 13;
if(ch == 'd')
return 13;
if(ch == 'E')
return 14;
if(ch == 'e')
return 14;
if(ch == 'F')
return 15;
if(ch == 'f')
return 15;
else return -1;
}