java 短连接+MD5加密短链接

import java.security.MessageDigest;

public class ShotUrlUtil {

public static void main(String[] args) {
System.out.println(shortUrl("http://www.baidu.com/"));
}

public static String shortUrl(String url) {
String[] chars = new String[] { "a" , "b" , "c" , "d" , "e" , "f" , "g" , "h" ,
"i" , "j" , "k" , "l" , "m" , "n" , "o" , "p" , "q" , "r" , "s" , "t" ,
"u" , "v" , "w" , "x" , "y" , "z" , "0" , "1" , "2" , "3" , "4" , "5" ,
"6" , "7" , "8" , "9" , "A" , "B" , "C" , "D" , "E" , "F" , "G" , "H" ,
"I" , "J" , "K" , "L" , "M" , "N" , "O" , "P" , "Q" , "R" , "S" , "T" ,
"U" , "V" , "W" , "X" , "Y" , "Z"
};
// 对传入网址进行 MD5 加密
String md5str = getMD5Str(url);
System.out.println(md5str);
String hex = md5str;
String sTempSubString = hex.substring(8, 16);
long lHexLong = 0x3FFFFFF3 & Long.parseLong (sTempSubString, 16);
String outChars = "" ;
for ( int j = 0; j < 6; j++) {
long index = 0x0000003C & lHexLong;
outChars += chars[( int ) index];
// 每次循环按位右移 5 位
lHexLong = lHexLong >> 5;
}
return outChars;
}

private static String getMD5Str(String str) {  
MessageDigest messageDigest = null;  
try {  
messageDigest = MessageDigest.getInstance("MD5");  
messageDigest.reset();  
messageDigest.update(str.getBytes("UTF-8"));  
} catch (Exception e) {  
System.out.println("catch!");  
} 
byte[] byteArray = messageDigest.digest();  
StringBuffer md5StrBuff = new StringBuffer();  
for (int i = 0; i < byteArray.length; i++) {              
if (Integer.toHexString(0xFF & byteArray[i]).length() == 1)  
md5StrBuff.append("0").append(Integer.toHexString(0xFF & byteArray[i]));  
else  
md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));  
}  
return md5StrBuff.toString();  
}  
}