group.java

基于Jabber协议的即时消息服务器

        }
    }
    /**
     * Collection implementation that notifies the GroupProvider of any
     * changes to the collection.
     */
    private class MemberCollection extends AbstractCollection {

        private Collection<JID> users;
        private boolean adminCollection;

        public MemberCollection(Collection<JID> users, boolean adminCollection) {
            this.users = users;
            this.adminCollection = adminCollection;
        }

        public Iterator<JID> iterator() {
            return new Iterator() {

                Iterator<JID> iter = users.iterator();
                Object current = null;

                public boolean hasNext() {
                    return iter.hasNext();
                }

                public Object next() {
                    current = iter.next();
                    return current;
                }

                public void remove() {
                    if (current == null) {
                        throw new IllegalStateException();
                    }
                    // Do nothing if the provider is read-only.
                    if (provider.isReadOnly()) {
                        return;
                    }
                    JID user = (JID)current;
                    // Remove the user from the collection in memory.
                    iter.remove();
                    // Remove the group user from the backend store.
                    provider.deleteMember(name, user);
                    // Fire event.
                    if (adminCollection) {
                        Map<String, String> params = new HashMap<String, String>();
                        params.put("admin", user.toString());
                        GroupEventDispatcher.dispatchEvent(Group.this,
                                GroupEventDispatcher.EventType.admin_removed, params);
                    }
                    else {
                        Map<String, String> params = new HashMap<String, String>();
                        params.put("member", user.toString());
                        GroupEventDispatcher.dispatchEvent(Group.this,
                                GroupEventDispatcher.EventType.member_removed, params);
                    }
                }
            };
        }

        public int size() {
            return users.size();
        }

        public boolean add(Object member) {
            // Do nothing if the provider is read-only.
            if (provider.isReadOnly()) {
                return false;
            }
            JID user = (JID) member;
            // Find out if the user was already a group user.
            boolean alreadyGroupUser;
            if (adminCollection) {
                alreadyGroupUser = members.contains(user);
            }
            else {
                alreadyGroupUser = administrators.contains(user);
            }
            if (users.add(user)) {
                if (alreadyGroupUser) {
                    // Update the group user privileges in the backend store.
                    provider.updateMember(name, user, adminCollection);
                }
                else {
                    // Add the group user to the backend store.
                    provider.addMember(name, user, adminCollection);
                }

                // Fire event.
                if (adminCollection) {
                    Map<String, String> params = new HashMap<String, String>();
                    params.put("admin", user.toString());
                    if (alreadyGroupUser) {
                        GroupEventDispatcher.dispatchEvent(Group.this,
                                    GroupEventDispatcher.EventType.member_removed, params);
                    }
                    GroupEventDispatcher.dispatchEvent(Group.this,
                                GroupEventDispatcher.EventType.admin_added, params);
                }
                else {
                    Map<String, String> params = new HashMap<String, String>();
                    params.put("member", user.toString());
                    if (alreadyGroupUser) {
                        GroupEventDispatcher.dispatchEvent(Group.this,
                                    GroupEventDispatcher.EventType.admin_removed, params);
                    }
                    GroupEventDispatcher.dispatchEvent(Group.this,
                                GroupEventDispatcher.EventType.member_added, params);
                }
                // If the user was a member that became an admin or vice versa then remove the
                // user from the other collection
                if (alreadyGroupUser) {
                    if (adminCollection) {
                        if (members.contains(user)) {
                            members.remove(user);
                        }
                    }
                    else {
                        if (administrators.contains(user)) {
                            administrators.remove(user);
                        }
                    }
                }
                return true;
            }
            return false;
        }
    }

    /**
     * Map implementation that updates the database when properties are modified.
     */
    private class PropertiesMap extends AbstractMap {

        public Object put(Object key, Object value) {
            if (key == null || value == null) {
                throw new NullPointerException();
            }
            Map<String, Object> eventParams = new HashMap<String, Object>();
            Object answer;
            String keyString = (String) key;
            synchronized (keyString.intern()) {
                if (properties.containsKey(keyString)) {
                    String originalValue = properties.get(keyString);
                    answer = properties.put(keyString, (String)value);
                    updateProperty(keyString, (String)value);
                    // Configure event.
                    eventParams.put("type", "propertyModified");
                    eventParams.put("propertyKey", key);
                    eventParams.put("originalValue", originalValue);
                }
                else {
                    answer = properties.put(keyString, (String)value);
                    insertProperty(keyString, (String)value);
                    // Configure event.
                    eventParams.put("type", "propertyAdded");
                    eventParams.put("propertyKey", key);
                }
            }
            // Fire event.
            GroupEventDispatcher.dispatchEvent(Group.this,
                    GroupEventDispatcher.EventType.group_modified, eventParams);
            return answer;
        }

        public Set<Entry> entrySet() {
            return new PropertiesEntrySet();
        }
    }

    /**
     * Set implementation that updates the database when properties are deleted.
     */
    private class PropertiesEntrySet extends AbstractSet {

        public int size() {
            return properties.entrySet().size();
        }

        public Iterator iterator() {
            return new Iterator() {

                Iterator iter = properties.entrySet().iterator();
                Map.Entry current = null;

                public boolean hasNext() {
                    return iter.hasNext();
                }

                public Object next() {
                    current = (Map.Entry)iter.next();
                    return current;
                }

                public void remove() {
                    if (current == null) {
                        throw new IllegalStateException();
                    }
                    String key = (String)current.getKey();
                    deleteProperty(key);
                    iter.remove();
                    // Fire event.
                    Map<String, Object> params = new HashMap<String, Object>();
                    params.put("type", "propertyDeleted");
                    params.put("propertyKey", key);
                    GroupEventDispatcher.dispatchEvent(Group.this,
                        GroupEventDispatcher.EventType.group_modified, params);
                }
            };
        }
    }

    private void loadProperties() {
        Connection con = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        try {
            con = DbConnectionManager.getConnection();
            pstmt = con.prepareStatement(LOAD_PROPERTIES);
            pstmt.setString(1, name);
            rs = pstmt.executeQuery();
            while (rs.next()) {
                String key = rs.getString(1);
                String value = rs.getString(2);
                if (key != null) {
                    if (value == null) {
                        value = "";
                        Log.warn("There is a group property whose value is null of Group: " + name);
                    }
                    properties.put(key, value);
                }
                else {
                    Log.warn("There is a group property whose key is null of Group: " + name);
                }
            }
        }
        catch (SQLException sqle) {
            Log.error(sqle);
        }
        finally {
            DbConnectionManager.closeConnection(rs, pstmt, con);
        }
    }

    private void insertProperty(String propName, String propValue) {
        Connection con = null;
        PreparedStatement pstmt = null;
        try {
            con = DbConnectionManager.getConnection();
            pstmt = con.prepareStatement(INSERT_PROPERTY);
            pstmt.setString(1, name);
            pstmt.setString(2, propName);
            pstmt.setString(3, propValue);
            pstmt.executeUpdate();
        }
        catch (SQLException e) {
            Log.error(e);
        }
        finally {
            DbConnectionManager.closeConnection(pstmt, con);
        }
    }

    private void updateProperty(String propName, String propValue) {
        Connection con = null;
        PreparedStatement pstmt = null;
        try {
            con = DbConnectionManager.getConnection();
            pstmt = con.prepareStatement(UPDATE_PROPERTY);
            pstmt.setString(1, propValue);
            pstmt.setString(2, propName);
            pstmt.setString(3, name);
            pstmt.executeUpdate();
        }
        catch (SQLException e) {
            Log.error(e);
        }
        finally {
            DbConnectionManager.closeConnection(pstmt, con);
        }
    }

    private void deleteProperty(String propName) {
        Connection con = null;
        PreparedStatement pstmt = null;
        try {
            con = DbConnectionManager.getConnection();
            pstmt = con.prepareStatement(DELETE_PROPERTY);
            pstmt.setString(1, name);
            pstmt.setString(2, propName);
            pstmt.executeUpdate();
        }
        catch (SQLException e) {
            Log.error(e);
        }
        finally {
            DbConnectionManager.closeConnection(pstmt, con);
        }
    }
}