private synchronized void updateProperty(String key, String value, String originalValue) {
        Connection con = null;
        PreparedStatement pstmt = null;
        try {
            con = DbConnectionManager.getConnection();
            pstmt = con.prepareStatement(UPDATE_PROPERTY);
            pstmt.setString(1, value);
            pstmt.setString(2, key);
            pstmt.setString(3, group.getName());
            pstmt.executeUpdate();
        }
        catch (SQLException e) {
            logger.error(e.getMessage(), e);
        }
        finally {
            DbConnectionManager.closeConnection(pstmt, con);
        }

        // Clean up caches.
        DefaultGroupProvider.sharedGroupMetaCache.clear();
        GroupManager.getInstance().propertyModifiedPostProcess(group, key, originalValue);
    }
Update the value of an existing group property for the current group

@param key Property name
@param value Property value
@param originalValue Original property value
xmppserver/src/main/java/org/jivesoftware/openfire/group/DefaultGroupPropertyMap.java