MD5加密

import java.security.MessageDigest; 
import java.security.NoSuchAlgorithmException; 

public static String md5(String source){ 
    String dest = null; 
  try{ 
     MessageDigest md5 = MessageDigest.getInstance("MD5"); 
     char[] charArray = source.toCharArray();     
        byte[] byteArray = new byte[charArray.length];   
        for (int i=0; i<charArray.length; i++) 
           byteArray[i] = (byte) charArray[i];   
        byte[] md5Bytes = md5.digest(byteArray); 
        StringBuffer hexValue = new StringBuffer(); 
        for (int i=0; i<md5Bytes.length; i++) 
        { 
           int val = ((int) md5Bytes[i] ) & 0xff; 
           if (val < 16) hexValue.append("0"); 
           hexValue.append(Integer.toHexString(val)); 
        } 
        dest = hexValue.toString(); 
    }catch (NoSuchAlgorithmException e) { 
     e.printStackTrace(); 
    } 
    return dest; 
} 
//public static void main(String[] args) { 
  //System.out.println("BBBBBBBBB=="+MD5.md5("1234")); 
   // System.out.println("AAAAAAAAAAAAAAAA=="+new MD5().getChangeStr("1234abcd")); 
//} 
}