usermanagerbean.java

老外的在线考试

/*
 * UserEJB - CyberDemia's User management library implemented using EJBs.
 * Copyright (C) 2004 CyberDemia Research and Services
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 *
 * See the COPYING file located in the top-level-directory of
 * the archive of this library for complete text of license.
 */
package com.cyberdemia.user;
import javax.ejb.*;
import javax.naming.*;
import java.util.*;
import java.security.*;
import java.util.logging.*;
import com.cyberdemia.util.HexString;
import com.cyberdemia.ejb.BaseSessionBean;

/**
 * UserManagerBean is a facade that provides
 * useful methods for managing User and related beans.
 *
 * @ejb.bean name="UserManagerBean"
 *           type="Stateless"
 *           view-type="remote"
 *           jndi-name="ejb/UserManager"
 *
 * @ejb.util generate="physical"
 * @ejb.interface remote-class="com.cyberdemia.user.UserManager" extends="javax.ejb.EJBObject"
 * @ejb.home remote-class="com.cyberdemia.user.UserManagerHome" extends="javax.ejb.EJBHome"
 * @ejb.ejb-ref ejb-name="UserBean" ref-name="ejb/LocalUser" view-type="local"
 * @ejb.ejb-ref ejb-name="UserRoleBean" ref-name="ejb/LocalUserRole" view-type="local"
 * @ejb.ejb-ref ejb-name="ResourceReferenceBean" ref-name="ejb/LocalResourceReference" view-type="local"
 *
 * @author Alexander Yap
 * @version $Revision: 1.10 $ at $Date: 2004/06/19 14:25:59 $ by $Author: alexycyap $
 *
 */
public class UserManagerBean extends BaseSessionBean
{

	/**
	 * Adds a new user to the database using the data passed in
	 * by a UserData instance. Some fields in UserData are ignored, such
	 * as id and createdMillis.
	 * This method first checks that the user's login name does not match
	 * any existing login names in the database.
	 * Note that the lastName is always atored in all upper-case to simplify searching.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param data UserData instance storing data for the new user.
	 * @return Unique ID (primary key) of the new user.
	 * @throws RemoteException
	 * @throws UserException if the login name already exists in the database, or due to some other error.
	 */
	public Integer addUser(UserData data) throws UserException
	{
		if (isLoginExists(data.getLogin()))
		{
			throw new UserException(UserException.DUPLICATE_LOGIN, "User with login "+data.getLogin()+" already exists.");
		}

		Integer uid = null;
		// Last name is always saved in all upper case to simplify searching
		try
		{
			LocalUser user = s_userHome.create(data.login, data.password, data.email,
				data.title, data.firstName, data.lastName.toUpperCase() );
			uid = user.getGeneratedPrimaryKey();
		}
		catch (CreateException ex)
		{
			getSessionContext().setRollbackOnly();
			throw new UserException("Error adding user "+data.login, ex);
		}

		try
		{
			addRolesForUser(data.login, data.roles );
        }
		catch (CreateException cex)
		{
			getSessionContext().setRollbackOnly();
			throw new UserException("Error adding roles for user "+data.login, cex);
		}

		return uid;
	}

	/**
	 * Removed an existing user from the database.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param id Unique ID of user to remove.
	 * @throws RemoteException
	 * @throws UserException if there is an error.
	 */
	public void removeUser(Integer id) throws UserException
	{
		LocalUser user =  doFindUserById(id);

		try
		{
			user.removeAllResources();
			removeRolesForUser(user.getName());
			user.remove();
		}
		catch (Exception ex)
		{
			getSessionContext().setRollbackOnly();
			throw new UserException("Error removing user with ID "+id, ex);
		}
	}

	/**
	 * Gets the unique IDs of all users in the database.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @return Array of all user IDs.
	 */
	public Integer[] getUsers()
	{
		Integer[] ids = null;
		try
		{
			Iterator userIter = s_userHome.findAll().iterator();
			ArrayList idList = new ArrayList();
			while (userIter.hasNext())
			{
				LocalUser user = (LocalUser)userIter.next();
				idList.add( user.getPrimaryKey() );
			}
			ids = (Integer[])idList.toArray(new Integer[0]);
		}
		catch (Exception ex)
		{
			// If there is a problem finding users, just return empty array
			ids = new Integer[0];
		}
		return ids;
	}

	/**
	 * Gets the data of a user identified by its unique ID. 
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param id User ID.
	 * @param includeRoles true to also retrieve roles, false to skip them.
	 * @return UserData instance storing the user's data, or null if the user doesn't exist.
	 * @throws UserException if there is an error.
	 */
	public UserData getUserData(Integer id, boolean includeRoles) throws UserException
	{
		LocalUser user =  doFindUserById(id);

		UserData data = null;
		try
		{
			data = createUserData(user, includeRoles);
		}
		catch (Exception ex)
		{
			throw new UserException( "Error getting data for User "+user.getName(), ex);
		}
		return data;
	}

	/**
	 * Finds users by searching for a substring within the login name.
	 * The search may or may not be case-sensitive depending on the
	 * underlying database.
	 * For example, search string "lex@yah" will match login names
	 * like "[e-mail]" and "[e-mail]".
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param loginSearchStr Login substring to search for.
	 * @param limit Number to limit the results to.
	 * @param includeRoles true to also retrieve roles, false to skip them.
	 * @return Array of UserData instances for found users, or empty array if no user found.
	 */
	public UserData[] searchUsersByLogin(String loginSearchStr, int limit, boolean includeRoles)
	{	
		UserData[] userDataArr = null;
		try
		{
			Collection userCollection = s_userHome.findByLoginSubString(loginSearchStr, limit);
			userDataArr = convertUserCollectionToDataArray( userCollection, includeRoles);
		}
		catch (FinderException fex)
		{
			s_logger.log( Level.WARNING, "Cannot search User by login search string \""+loginSearchStr+"\"");
			userDataArr = new UserData[0];
		}
		return userDataArr;
	}
	
	/**
	 * Finds users by searching for a substring within the last name.
	 * The substring is converted to upper-case before being compared
	 * with values from database what are also all in upper-case. 
	 * Hence, the search is effectively case-insensitive regardless
	 * of the underlying database.
	 * For example, search string "le" will match last names
	 * like "alex", "leonardo" and "napolean".
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param lastNameSearchStr Last name substring to search for.
	 * @param limit Number to limit the results to.
	 * @param includeRoles true to also retrieve roles, false to skip them.
	 * @return Array of UserData instances for found users, or empty array if no user found.
	 */
	public UserData[] searchUsersByLastName(String lastNameSearchStr, int limit, boolean includeRoles)
	{
		UserData[] userDataArr = null;
		try
		{
			Collection userCollection = s_userHome.findByLastNameSubString(lastNameSearchStr.toUpperCase(), limit);
			userDataArr = convertUserCollectionToDataArray( userCollection, includeRoles);
		}
		catch (FinderException fex)
		{
			s_logger.log( Level.WARNING, "Cannot search User by lastName search string "+lastNameSearchStr);
			userDataArr = new UserData[0];
		}
		return userDataArr;
	}

	/**
	 * Gets the data of a user identified by its login name.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param login User login name
	 * @param includeRoles true to also retrieve roles, false to skip them.
	 * @return UserData instance storing the user's data, or null if the user doesn't exist.
	 */
	public UserData getUserDataByLogin(String login, boolean includeRoles)
	{
		UserData data = null;
		LocalUser user = findUserByLogin(login);
		if (user != null)
		{
			data = createUserData(user, includeRoles);
		}
		else
		{	// return null if user not found.
			s_logger.log( Level.WARNING, "Cannot find User with login "+login);
		}
		return data;
	}

	/**
	* Checks if any user with the specified login name already exists in the database.
	* Login name comparison is case-insensitive.
	*
	* @ejb.interface-method
	* @ejb.transaction type="Required"
	*
	* @param loginName Login name to check for.
	* @return true if a user with the login name exists, otherwise false.
	*/
	public boolean isLoginExists(String loginName)
	{
		boolean exists = false;
		try
		{
			exists = !s_userHome.findByLogin(loginName.toLowerCase()).isEmpty();
		}
		catch (FinderException fex)
		{
            // Ignore, exists remains false.
		}
		return exists;
	}

	/**
	 * Updates an existing user with new data passed in as a UserData instance.
	 * The user to modify is identified by UserData's id field.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param data UserData instance storing user data.
	 * @throws RemoteException
	 * @throws UserException if an error occurs such as the id is invalid.
	 */
	public void setUser(UserData data) throws UserException
	{
		String hashedPassword = null;
		if ( (data.password!=null) && (data.password.length()>0))
		{
			try
			{
				byte[] hashed = MessageDigest.getInstance("MD5").digest( data.password.getBytes() );
				hashedPassword =  HexString.toString(hashed) ;
			}
			catch (NoSuchAlgorithmException ex)
			{
				throw new UserException("Cannot create MD5 MessageDigest",ex);
			}
		}

		LocalUser user =  doFindUserById(data.id);

		try
		{
			user.setEmail( data.email );
			if ( hashedPassword!=null )
			{
				user.setHashedPassword(hashedPassword);
			}
			user.setName( data.login );
			user.setTitle( data.title );
			user.setFirstName( data.firstName );
			// Last name is always saved in all upper case to simplify searching
			user.setLastName( data.lastName.toUpperCase() );
			user.setLastModifiedMillis( System.currentTimeMillis() );
		}
		catch (Exception ex)
		{
			getSessionContext().setRollbackOnly();
			throw new UserException("Error setting data for User "+data.login, ex);
		}

		// Refresh the roles for this user in case they have changed, if roles are available.
		if (data.roles!=null)
		{