Spring-security md5 encryption and implementation of java

<authentication-manager>
    <authentication-provider>
        <!--<user-service>-->
            <!--<user name="admin" password="admin" authorities="ROLE_USER" />-->
        <!--</user-service>-->
<jdbc-user-service data-source-ref="dataSource"
users-by-username-query="select username, password, 1 enabled from t_sys_info where username = ?"
authorities-by-username-query="select username, 'ROLE_USER' authority from t_sys_info where username = ?"></jdbc-user-service><password-encoder base64="true" hash="md5"></                                                                  
        password-encoder>
    </authentication-provider>
</authentication-manager>

public static String encoderByMd5(String str){
     //Determine the calculation method
     MessageDigest md5= null ;
    String newstr= null;
    try {
        md5 = MessageDigest.getInstance("MD5");
        BASE64Encoder base64en = new BASE64Encoder();
         //encrypted string
         newstr=base64en.encode(md5.digest(str.getBytes( "utf-8" )));
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace ();
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace ();
    }

    return newstr;

}