usermanagerbean.java

老外的在线考试

/*
 * UserEJB - CyberDemia's User management library implemented using EJBs.
 * Copyright (C) 2003 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.impl;
import javax.ejb.*;
import javax.naming.*;
import java.util.*;
import java.security.*;
import java.util.logging.*;
import com.cyberdemia.user.*;
import com.cyberdemia.util.HexString;

/**
* UserManagerBean is a session bean implementation
* of UserManager.
*
* @author Alexander Yap
*/
public class UserManagerBean implements SessionBean
{
	/**
	 * 
	 * Creates an instance of UserManagerBean.
	 *
	 */
	public UserManagerBean()
	{
		try
		{
			Context ctx = new InitialContext();
			m_userHome = (LocalUserHome)ctx.lookup("java:comp/env/ejb/localUser");
			m_userRoleHome = (LocalUserRoleHome)ctx.lookup("java:comp/env/ejb/localUserRole");
			m_resourceRefHome = (LocalResourceReferenceHome)ctx.lookup("java:comp/env/ejb/localResourceReference");
		}
		catch (Exception ex)
		{
			throw new EJBException(ex);
		}

	}
	
	/**
	 * 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 email address does not match
	 * any existing email addresses in the database.
	 * Note that the lastName is always atored in all upper-case to simplify searching.
	 * 
	 * @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 email address already exists in the database, or due to some other error.
	 */
	public String addUser(UserData data) throws UserException
	{
		if (isEmailExists(data.getEmail()))
		{
			throw new UserException(UserException.DUPLICATE_EMAIL, "User with email "+data.getEmail()+" already exists.");
		}
		
		String uid = null;
		// Last name is always saved in all upper case to simplify searching
		try
		{
			LocalUser user = m_userHome.create(data.password, data.email, 
				data.title, data.firstName, data.lastName.toUpperCase(), data.groups );
			uid = user.getId();
		}
		catch (Exception ex)
		{
			throw new UserException("Error adding user with email "+data.getEmail(), ex);
		}
		
		addRolesForUserId(uid, data.groups );

		return uid;
	}

	/**
	 * Removed an existing user from the database.
	 * @param id Unique ID of user to remove.
	 * @throws RemoteException
	 * @throws UserException if there is an error.
	 */
	public void removeUser(String id) throws UserException
	{
		try
		{
			LocalUser user = m_userHome.findByPrimaryKey(id);
			user.removeAllResources();
			removeRolesForUserId(id);
			user.remove();
		}
		catch (FinderException fex)
		{
			s_logger.log( Level.WARNING, "Cannot find User with ID "+id);
			throw new UserException(UserException.USER_NOT_FOUND, "Cannot find User with ID "+id);
		}
		catch (Exception ex)
		{
			throw new UserException("Error removing user with ID "+id, ex);
		}
	}

	/**
	 * Gets the unique IDs of all users in the database.
	 * @return Array of all user IDs.
	 * @throws RemoteException
	 */
	public String[] getUsers()
	{
		String[] ids = null;
		try
		{
			Iterator userIter = m_userHome.findAll().iterator();
			ArrayList idList = new ArrayList();
			while (userIter.hasNext())
			{
				LocalUser user = (LocalUser)userIter.next();
				idList.add( user.getPrimaryKey() );
			}
			ids = (String[])idList.toArray(new String[0]);
		}
		catch (Exception ex)
		{
			throw new EJBException(ex);
		}
		return ids;
	}

	/**
	 * Gets the data of a user identified by its unique ID. 
	 * @param id User ID.
	 * @return UserData instance storing the user's data, or null if the user doesn't exist.
	 * @throws RemoteException
	 */
	public UserData getUserData(String id)
	{
		UserData data = null;
		try
		{
			LocalUser user = m_userHome.findByPrimaryKey(id);
			data = user.getUserData();
		}
		catch (FinderException ex)
		{	// return null if user not found.
			s_logger.log( Level.WARNING, "Cannot find User with id "+id);
		}
		return data;
	}

	/**
	 * Finds users by searching for a substring within the email address.
	 * The search may or may not be case-sensitive depending on the
	 * underlying database.
	 * For example, search string "lex@yah" will match email addresses
	 * like "[e-mail]" and "[e-mail]".
	 * 
	 * @param emailSearchStr Email address substring to search for.
	 * @return Array of UserData instances for found users, or empty array if no user found.
	 * @throws RemoteException
	 */
	public UserData[] searchUsersByEmail(String emailSearchStr)
	{	
		UserData[] userDataArr = null;
		try
		{
			Collection userCollection = m_userHome.findByEmailSubString(emailSearchStr);
			userDataArr = new UserData[userCollection.size()];
			Iterator userIter = userCollection.iterator();
			for (int uidx=0; userIter.hasNext(); uidx++)
			{
				LocalUser user = (LocalUser)userIter.next();
				userDataArr[uidx] = user.getUserData();
			}
		}
		catch (FinderException fex)
		{
			s_logger.log( Level.WARNING, "Cannot search User by email search string "+emailSearchStr);
			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".
	 *
	 * @param lastNameSearchStr Last name substring to search for.
	 * @return Array of UserData instances for found users, or empty array if no user found.
	 * @throws RemoteException
	 */
	public UserData[] searchUsersByLastName(String lastNameSearchStr)
	{
		UserData[] userDataArr = null;
		try
		{
			Collection userCollection = m_userHome.findByLastNameSubString(lastNameSearchStr.toUpperCase());
			userDataArr = new UserData[userCollection.size()];
			Iterator userIter = userCollection.iterator();
			for (int uidx=0; userIter.hasNext(); uidx++)
			{
				LocalUser user = (LocalUser)userIter.next();
				userDataArr[uidx] = user.getUserData();
			}
		}
		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 unique ID.  
	 * @param email User email address
	 * @return UserData instance storing the user's data, or null if the user doesn't exist.
	 * @throws RemoteException
	 */
	public UserData getUserDataByEmail(String email)
	{
		UserData data = null;
		LocalUser user = findUserByEmail(email);
		if (user != null)
		{
			data = user.getUserData();
		}
		else
		{	// return null if user not found.
			s_logger.log( Level.WARNING, "Cannot find User with email "+email);
		}
		return data;
	}
	
	/**
	 * Checks if any user with the specified email address already exists in the database.
	 * @param email Email address to check for.
	 * @return true if a user with the email address exist, otherwise false.
	 * @throws RemoteException
	 */
	public boolean isEmailExists(String email)
	{
		return (findUserByEmail(email)!=null);
	}
	
	/**
	 * Updates an existing user with new data passed in as a UserData instance.
	 * The user to modify is identified by UserData's id field.
	 * @param data UserData instance storing user data.
	 * @throws RemoteException
	 * @throws UserException if an error occurs such as the id is invalid.
	 */
	public void setUserData(UserData data) throws UserException
	{
		try
		{
			LocalUser user = m_userHome.findByPrimaryKey(data.id);
			user.setUserData(data);
		}
		catch (FinderException ex)
		{
			throw new UserException(UserException.USER_NOT_FOUND, "Cannot find User with ID "+data.id);
		}
		// refresh the roles for this user in case the groups have changed.
		removeRolesForUserId(data.id);
		addRolesForUserId(data.id, data.groups );
	}


	/**
	* Validates a User ID against a specified password. 
	* This method is provided in case the client code needs to perform some
	* programmatic authentication. If authentication is managed by the container,
	* there is no need for this method.
	* @param id User ID to validate.
	* @param password  Password of user.
	* @return true if user is valid and the password matches, otherwise false
	*/
	public boolean validateUser(String id, String password)
	{
		LocalUser user = null;
		try
		{
			user = m_userHome.findByPrimaryKey(id);
		}
		catch (FinderException ex)
		{
			return false;
		}
		assert user!=null : "User is null for id "+id;
		
		String hashedHex = null;
		try
		{
			byte[] hashed = MessageDigest.getInstance("MD5").digest( password.getBytes() );
			hashedHex = HexString.toString(hashed);
		}
		catch (NoSuchAlgorithmException ex)
		{
			s_logger.log(Level.SEVERE, "Cannot create MD5 MessageDigest",ex);
			return false;
		}

		return user.getHashedPassword().equalsIgnoreCase(hashedHex);
	}

	/**
	* Gets resources within the specified category that are
	* associated with the specified user.
	* @param id User ID
	* @param catKey  Key to identify the category of resource to extract, or null to extract all resources.
	* @return Array of resource IDs.
	*/
	public String[] getResourcesInUser( String id, String catKey )
	{
		String[] resourceIds = null;
		try
		{
			LocalUser user = m_userHome.findByPrimaryKey(id);
			LocalResourceReference[] resourceRefs = user.getResources( catKey );
			resourceIds = new String[ resourceRefs.length ];
			for (int ridx=0; ridx<resourceIds.length; ridx++)
			{
				resourceIds[ridx] = resourceRefs[ridx].getResourceId();
			}
		}
		catch (FinderException fex)
		{
			s_logger.log( Level.WARNING, "Cannot find User with id "+id);
		}
		catch (Exception ex)
		{
			throw new EJBException(ex);
		}
		return resourceIds;
	}

	/**
	* Associates a resource with the specified user.
	* @param id User ID
	* @param catKey  Key to identify the category of resource to add.
	* @param resId   The ID of the resource to add.
	* @return true if resource is added successfully, otherwise false (it already exists).
	*/
	public boolean addResourceToUser( String id, String catKey, String resId )
	{
		boolean success = false;
		try
		{
			LocalUser user = m_userHome.findByPrimaryKey(id);
			// Try to find if the reference already exists, if not create a new one.
			LocalResourceReference resRef = null;
			try
			{
				Iterator resRefIter  = m_resourceRefHome.findByCategoryAndResource(catKey, resId).iterator();
				if (resRefIter.hasNext())
				{
					resRef = (LocalResourceReference)resRefIter.next();
				}
				else
				{
					resRef = m_resourceRefHome.create( catKey, resId );
				}
			}
			catch (FinderException fex)
			{
				resRef = m_resourceRefHome.create( catKey, resId );
			}
			success = user.addResource( resRef );
		}
		catch (Exception ex)
		{
			throw new EJBException(ex);
		}
		return success;
	}

	/**
	* Removes a resource from the specified user.
	* @param id User ID
	* @param catKey  Key to identify the category of resource to remove.
	* @param resId   The ID of the resource to remove.
	* @return true if resource is removed successfully, otherwise false (not found).
	*/
	public boolean removeResourceFromUser( String id, String catKey, String resId )
	{
		// If the reference doesn't exist, skip everything because there is nothing to remove
		LocalResourceReference resRef = null;
		try
		{
			Iterator resRefIter  = m_resourceRefHome.findByCategoryAndResource(catKey, resId).iterator();
			if (resRefIter.hasNext())
			{
				resRef = (LocalResourceReference)resRefIter.next();
			}
		}
		catch (FinderException fex)
		{
		}
		
		if (resRef==null)
		{
			return false;
		}

		boolean success = false;
		try
		{
			LocalUser user = m_userHome.findByPrimaryKey(id);
			success = user.removeResource( resRef );
		}
		catch (Exception ex)
		{
			throw new EJBException(ex);
		}
		return success;
	}
	
	/**
	* Gets roles that are associated with the specified user.
	* @param id User ID
	* @return Array of role names, or empty array if none.
	*/
	public String[] getRolesInUser( String id )
	{
		ArrayList roleList = new ArrayList();
		try
		{
			Collection uRoles = m_userRoleHome.findByUserId(id.toString());
			Iterator uRoleIter = uRoles.iterator();
			while (uRoleIter.hasNext())
			{
				roleList.add( ((LocalUserRole)uRoleIter).getRoleName() );
			}
		}
		catch (FinderException fex2)
		{
			// Its alright for a user not to have any role
		}
		return (String[])roleList.toArray(new String[0]);
	}
	
	/**
	* Associates roles with specified user.
	*/
	private void addRolesForUserId( String id, String groups)
	{
		String[] roles = UserUtils.getRolesForGroups(groups);
		try
		{
			for (int r=0; r<roles.length; r++)
			{
				m_userRoleHome.create( id.toString(), roles[r]);
			}
		}
		catch (Exception ex)
		{
			throw new EJBException(ex);
		}
	}
	
	/**
	* Removes any roles associated with specified user id.
	*/
	private void removeRolesForUserId( String id )
	{
		try
		{
			Collection uRoles = m_userRoleHome.findByUserId(id.toString());
			Iterator uRoleIter = uRoles.iterator();
			while (uRoleIter.hasNext())
			{
				((LocalUserRole)uRoleIter.next()).remove();
			}
		}
		catch (FinderException fex2)
		{
			// Its alright for a user not to have any role
		}
		catch (Exception ex)
		{
			throw new EJBException(ex);
		}
	}

	private LocalUser findUserByEmail(String email)
	{
		LocalUser user = null;
		try
		{
			Iterator userIter = m_userHome.findByEmail(email).iterator();
			if (userIter.hasNext())
			{
				user = (LocalUser)userIter.next();
			}
		}
		catch (FinderException fex)
		{
		}		
		return user;
	}

	public void ejbCreate() {}
	public void ejbPostCreate() { }
	public void ejbRemove() {}
	public void ejbActivate() {}
	public void ejbPassivate() {}

	public void setSessionContext(SessionContext sc)
	{
		m_context = sc;
	}

	private SessionContext m_context = null;
	private LocalUserHome m_userHome = null;
	private LocalUserRoleHome m_userRoleHome = null;
	private LocalResourceReferenceHome m_resourceRefHome = null;
	private static Logger s_logger = Logger.getLogger(UserManagerBean.class.getName());
}