java的MD5加密

十六位的md5加密
private static void Md5(String plainText ) { 
try { 
MessageDigest md = MessageDigest.getInstance("MD5"); 
md.update(plainText.getBytes()); 
byte b[] = md.digest(); 

int i; 

StringBuffer buf = new StringBuffer(""); 
for (int offset = 0; offset < b.length; offset++) { 
i = b[offset]; 
if(i<0) i+= 256; 
if(i<16) 
buf.append("0"); 
buf.append(Integer.toHexString(i)); 
} 

System.out.println("result: " + buf.toString());//32位的加密 

System.out.println("result: " + buf.toString().substring(8,24));//16位的加密 

} catch (NoSuchAlgorithmException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 
} 

Md5("12312312312312"); 结果: 
result: ba56bab91016bcb37878e06c16e9e68f