MD5 单向加密，为保存用户密码

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.logging.Level;
import java.util.logging.Logger;
public class MD5{
//MD5加密
public String md5(String str) {
String s=str;
if(s==null){
return "";
}else{
String value = null;
MessageDigest md5 = null;
try {
md5 = MessageDigest.getInstance("MD5");
}catch (NoSuchAlgorithmException ex) {
//Logger.getLogger(MD5.class.getName()).log(Level.SEVERE, null, ex);
}
sun.misc.BASE64Encoder baseEncoder = new sun.misc.BASE64Encoder();
try {
value = baseEncoder.encode(md5.digest(s.getBytes("utf-8")));
} catch (Exception ex) {
}
return value;
}
}
public static void main(String[] args) {
MD5 m = new MD5();
System.out.println(m.md5("aaronuu"));
}
}