Custom Login Module

import com.sun.appserv.security.AppservPasswordLoginModule;
import com.sun.enterprise.security.auth.realm.jdbc.JDBCRealm;
import javax.security.auth.login.LoginException;

/**
* Class SimpleCustomLogin is used for designing our own custom module
* it extends a class provided by GF server that helps us authenticating the user
* Using this we need to take care of single method authenticateUser() that will
* have our logic to confirm about the user.
*/
public class SimpleCustomLoginModule extends AppservPasswordLoginModule {

public SimpleCustomLoginModule() {

//maintaining the log to ensure that our LoginModule is initialized.
log("SimpleCustomLoginModule: Initialization");

}//end of constructor

/**
* this method helps us maintain server log
* so that we can make amendments according to our need
* and it also helps determining the flow.
*/
private void log(String s) {
System.out.println((new StringBuilder())
.append("SimpleCustomLoginModule::").append(s).toString());
}//end of log()

/**
* This is the method we need to overrdide which will have our LOGIC for
* authentication .In this we are using the DATABASE as backend for user.
* So we need to use the JDBCRealm ( Realm - is a set of roles of user
* with their respective users to know more about realm check this out
* http://download.oracle.com/javaee/5/tutorial/doc/
* OR
* http://download-llnw.oracle.com/javaee/6/tutorial/doc/bncas.html).
* Now we need to configure this realm in
* our web.xml under login-config tag from where the server retrieves it.
* Also maintaining evrything in the server log as well.
* We paas authenticated user group(roles here) to commitUserAuthentication
* method for authorization.

*/
@Override
protected void authenticateUser() throws LoginException
{
System.out.println("in authenticate user.....");
//getting the instance of current realm as JDBCRealm
JDBCRealm samplerealm = (JDBCRealm)_currentRealm;
System.out.println("jdbc realm as ....." +samplerealm);

/**
* Checking the instance of the realm whether its taking our JDBC realm
* or not. This will load the user's from database with their name,
* password and roles. Else if not will throw LoginException.
*/
if ( !( _currentRealm instanceof JDBCRealm ) ) {
String msg = sm.getString("filelm.badrealm");
System.out.println("not instance of jdbc realm ....");
throw new LoginException(msg);
}

/**
* Here we get the user's roles from the database in grplist array.
* But here we get only one element in the array.So we need to check.
* Since the value stored in table is in form of varchar(simple strings)
* as roles -- "user,test,......so on"
* Hence we separate it later in groupListToForward.
*/
String[] grpList = samplerealm.authenticate(_username, _password);
System.out.println("username " + _username + "password " + _password);
System.out.println("length from jdbc authenticate ... groups are.." + grpList);

/**
* This id to check whether the user group(role) is null or not.
*/
if ( grpList == null ) { // JAAS behavior
String msg = sm.getString("filelm.faillogin", _username);
throw new LoginException(msg);
}//endif


/**
* make a copy of groupList to pass to LoginModule.
* DO NOT PASS the grpList as is - as it will get overwritten.
* Resulting in logins passing only once.
* In the above grouplist we get only string with multiple user's role.
* grplist value will be like "user,weballow,test"
* But here we split them into multiple roles as roles as
* 1. user 2. weballow 3. test
* That will be passed for proper authorization.
*/
String[] groupListToForward = grpList[0].toString().split(",");
System.out.println("values of group array ..." + groupListToForward.length);
for (int i = 0; i< groupListToForward.length; i++) {
System.out.println("value of groups " + groupListToForward[i].toString());
 }
System.out.println("calling commit...");
commitUserAuthentication(groupListToForward);
  }//end of authernticateUser()

}//end of SimpleCustomLoginModule