usermanager.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Ozone Core License version 1 published by ozone-db.org.
//
// The original code and portions created by SMB are
// Copyright (C) 1997-@year@ by SMB GmbH. All rights reserved.
//
// $Id: UserManager.java,v 1.2 2002/06/08 00:49:38 mediumnet Exp $

package org.ozoneDB.core;

import java.io.*;
import org.ozoneDB.DxLib.*;
import org.ozoneDB.util.*;


/**
 * The UserManager holds all information about users and groups.
 *
 * @author <a href="http://www.softwarebuero.de/">SMB</a>
 * @version $Revision: 1.2 $Date: 2002/06/08 00:49:38 $
 * @see User
 * @see Group
 */
public final class UserManager extends ServerComponent {

    // magic number for streaming
    protected final static long serialVersionUID = 2;
    protected final static byte subSerialVersionUID = 1;

    // property names
    public final static String GROUP_TABLE = "ozoneDB.userManager.groupTable";
    public final static String USER_TABLE = "ozoneDB.userManager.userTable";

    protected transient Env env;

    /**
     * All currently known users. Maps String into User.
     */
    protected DxMap userTable;

    /**
     * All currently known users. Maps IDs into User.
     */
    protected DxMap idUserTable;

    /**
     * All currently known groups. Maps String into Group.
     */
    protected DxMap groupTable;

    /**
     * All currently known groups. Maps IDs into Group.
     */
    protected DxMap idGroupTable;


    /**
    	This is the userID of the system. The system has all rights and is comparable to root in
    	UNIX systems.
    */
    protected final static int SYSTEM_USER_ID = -1;

    /**
    	The User object of the GarbageCollector.
    */
    protected final static User garbageCollectorUser    =	new User("garbageCollector",SYSTEM_USER_ID);

	/**
		Returns the User object of the GarbageCollector.
	*/
    protected User getGarbageCollectorUser() {
    	return garbageCollectorUser;
    }

    public UserManager( Env _env ) {
        super( _env );
        env = _env;
        groupTable = new DxHashMap();
        userTable = new DxHashMap();
    }


    public void startup() throws Exception {
        env.logWriter.newEntry( this, "startup...", LogWriter.INFO );

        groupTable = (DxMap)env.state.property( GROUP_TABLE, null );
        userTable = (DxMap)env.state.property( USER_TABLE, null );

        boolean isInitialized = true;
        if (groupTable == null || userTable == null) {
            env.logWriter.newEntry( this, "No state properties found. Initializing...", LogWriter.INFO );
            groupTable = new DxHashMap();
            idGroupTable = new DxHashMap();
            userTable = new DxHashMap();
            isInitialized = false;
        }

        // initialize idUserTable from the content of userTable
        idUserTable = new DxHashMap();
        DxIterator it = userTable.iterator();
        User user;
        while ((user = (User)it.next()) != null) {
            idUserTable.addForKey( user, user.id() );
        }

        // initialize idGroupTable from the content of groupTable
        idGroupTable = new DxHashMap();
        it = groupTable.iterator();
        Group group;
        while ((group = (Group)it.next()) != null) {
            idGroupTable.addForKey( group, group.id() );
        }

        // add admin user and group
        if (isInitialized == false) {
            String adminName = System.getProperty( "user.name" );

            env.logWriter.newEntry( this, "admin user: " + adminName, LogWriter.INFO );

            newUser( adminName, 0 );
            newGroup( "admin", 0 );
            addUserToGroup( adminName, "admin" );
        }
    }


    public void shutdown() throws Exception {
        env.logWriter.newEntry( this, "shutdown...", LogWriter.INFO );
        save();
    }


    public void save() throws Exception {
        env.state.setProperty( GROUP_TABLE, groupTable );
        env.state.setProperty( USER_TABLE, userTable );
    }


    public boolean checkPermission( User user, ObjectContainer container, int lockLevel ) {
        if (lockLevel <= Lock.LEVEL_READ) {
            return checkReadPermission( user, container );
        } else {
            return checkWritePermission( user, container );
        }
    }


    protected boolean checkReadPermission( User reader, ObjectContainer container ) {
        // allRead can be checked fast and is true in most cases so we
        // check it first
        if (container.permissions().allRead()) {
            return true;
        } else if (container.permissions().ownerID == reader.id) {

            return true;
        } else {

            if (container.permissions().groupRead()) {
                User owner = userForID( container.permissions().ownerID );
                // if reader is in any group of the owner permission is granted
                DxIterator it = groupsOfUser( owner ).iterator();
                Group group;
                while ((group = (Group)it.next()) != null) {
                    if (group.containsUser( reader )) {
                        return true;
                    }
                }
            }
        }

        if (reader.getID()==SYSTEM_USER_ID) {
            return true;
        }

        return false;
    }


    protected boolean checkWritePermission( User locker, ObjectContainer container ) {
        // allRead can be checked fast and is true in most cases so we
        // check it first
        if (container.permissions().allLock()) {
            return true;
        } else if (container.permissions().ownerID == locker.id) {

            return true;
        } else {

            if (container.permissions().groupLock()) {
                User owner = userForID( container.permissions().ownerID );
                // if reader is in any group of the owner permission is granted
                DxIterator it = groupsOfUser( owner ).iterator();
                Group group;
                while ((group = (Group)it.next()) != null) {
                    if (group.containsUser( locker )) {
                        return true;
                    }
                }
            }
        }

        if (locker.getID()==SYSTEM_USER_ID) {
            return true;
        }

        return false;
    }


    public void newGroup( String name, int id ) throws UserManagerException {
        if (name == null) {
            throw new UserManagerException( "username is null." );
        }
        Group group = new Group( name, id );

        if (groupForID( id ) != null) {
            throw new UserManagerException( "Group id " + id + " already exists." );
        }

        if (groupForName( name ) != null) {
            throw new UserManagerException( "Group name '" + name + "' already exists." );
        }

        groupTable.addForKey( group, name );
        idGroupTable.addForKey( group, new Integer( id ) );

        setChanged();
    }


    /**
     * Delete the group for the given name.
     */
    public void removeGroup( String name ) throws UserManagerException {
        if (name == null) {
            throw new UserManagerException( "username is null." );
        }
        Group group = groupForName( name );

        if (group == null) {
            throw new UserManagerException( "Group '" + name + "' does not exist." );
        }

        groupTable.removeForKey( group.name );
        idGroupTable.removeForKey( new Integer( group.id ) );

        setChanged();
    }


    protected DxBag groupsOfUser( User user ) {
        DxArrayBag result = new DxArrayBag();

        DxIterator it = groupTable.iterator();
        Group group;
        while ((group = (Group)it.next()) != null) {
            if (group.containsUser( user )) {
                result.add( group );
            }
        }
        return result;
    }


    public void newUser( String name, int id ) throws UserManagerException {
    	newUser( name, name, id);
    }


	public void newUser( String name, String passwd, int id ) throws UserManagerException {
		if (name == null) {
			throw new UserManagerException( "username is null." );
		}

		if (passwd == null) {
			passwd = name;
		}

		User user = new User( name, passwd, id );

		if (userForID( id ) != null) {
			throw new UserManagerException( "User id " + id + " already exists." );
		}
		if (userForName( name ) != null) {
			throw new UserManagerException( "User name '" + name + "' already exists." );
		}

		userTable.addForKey( user, user.name );
		idUserTable.addForKey( user, new Integer( user.id ) );

		setChanged();
	}


    public void addUserToGroup( String userName, String groupName ) throws UserManagerException {
        if (groupName == null) {
            throw new UserManagerException( "groupname is null." );
        }
        if (userName == null) {
            throw new UserManagerException( "username is null." );
        }
        Group group = groupForName( groupName );
        User user = userForName( userName );

        if (group == null) {
            throw new UserManagerException( "Group '" + groupName + "' does not exist." );
        }
        if (user == null) {
            throw new UserManagerException( "User '" + userName + "' does not exist." );
        }

        if (!group.addUser( user )) {
            throw new UserManagerException( "User '" + userName + "' is in this group already." );
        }

        setChanged();
    }


    public void removeUserFromGroup( String userName, String groupName ) throws UserManagerException {
        if (groupName == null) {
            throw new UserManagerException( "groupname is null." );
        }
        if (userName == null) {
            throw new UserManagerException( "username is null." );
        }
        Group group = groupForName( groupName );
        User user = userForName( userName );

        if (group == null) {
            throw new UserManagerException( "Group '" + groupName + "' does not exist." );
        }
        if (user == null) {
            throw new UserManagerException( "User '" + userName + "' does not exist." );
        }

        if (!group.containsUser( user )) {
            throw new UserManagerException( "User '" + userName + "' is not member of '" + groupName + "'." );
        }

        group.removeUser( user );
        setChanged();
    }


    public void removeUser( String name ) throws UserManagerException {
        if (name == null) {
            throw new UserManagerException( "username is null." );
        }
        User user = (User)userTable.removeForKey( name );
        if (user == null) {
            throw new UserManagerException( "User '" + name + "' does not exist." );
        }

        idUserTable.removeForKey( new Integer( user.id ) );

        // remove this user from all groups
        DxIterator it = groupsOfUser( user ).iterator();
        Group group;
        while ((group = (Group)it.next()) != null) {
            group.removeUser( user );
        }

        setChanged();
    }


    public Group groupForName( String name ) throws UserManagerException {
        if (name == null) {
            throw new UserManagerException( "username is null." );
        }
        return (Group)groupTable.elementForKey( name );
    }


    public Group groupForID( int id ) {
        return (Group)idGroupTable.elementForKey( new Integer( id ) );
    }


    public User userForName( String name ) throws UserManagerException {
        if (name == null) {
            throw new UserManagerException( "username is null." );
        }
        return (User)userTable.elementForKey( name );
    }


    public User userForID( int id ) {
        return (User)idUserTable.elementForKey( new Integer( id ) );
    }


    public DxCollection allGroups() {
        return groupTable;
    }


    public DxCollection allUsers() {
        return userTable;
    }
}