Java tutorial
/* * NOTE: This copyright does *not* cover user programs that use HQ * program services by normal system calls through the application * program interfaces provided as part of the Hyperic Plug-in Development * Kit or the Hyperic Client Development Kit - this is merely considered * normal use of the program, and does *not* fall under the heading of * "derived work". * * Copyright (C) [2004, 2005, 2006], Hyperic, Inc. * This file is part of HQ. * * HQ is free software; you can redistribute it and/or modify * it under the terms version 2 of the GNU General Public License as * published by the Free Software Foundation. This program 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 General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA. */ package org.hyperic.hq.ui.servlet; import java.io.IOException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * An <code>HttpServlet</code> that performs an availability lookup * and returns the image data for the icon that represents the lookup * result. */ public class AvailabilityServlet extends AvailabilityBaseServlet { private static final String ICON_ERR_URL = "/images/icon_available_error.gif"; private static final String ICON_AVAIL_URL = "/images/icon_available_green.gif"; private static final String ICON_UNAVAIL_URL = "/images/icon_available_red.gif"; private static final String ICON_WARNING_URL = "/images/icon_available_yellow.gif"; private static final String ICON_PAUSED_URL = "/images/icon_available_orange.gif"; private static final String ICON_POWERED_OFF_URL = "/images/icon_available_black.gif"; private static final String[] iconUrls = { ICON_ERR_URL, ICON_AVAIL_URL, ICON_UNAVAIL_URL, ICON_WARNING_URL, ICON_PAUSED_URL, ICON_POWERED_OFF_URL }; private static Log log = LogFactory.getLog(AvailabilityServlet.class.getName()); protected String[] getIconUrls() { return iconUrls; } protected void sendAvailIcon(HttpServletRequest request, HttpServletResponse response) { try { sendIcon(request, response, ICON_AVAIL_URL); } catch (Exception e) { log.debug("can't send avail icon: ", e); sendErrorIcon(request, response); } } protected void sendUnavailIcon(HttpServletRequest request, HttpServletResponse response) { try { sendIcon(request, response, ICON_UNAVAIL_URL); } catch (Exception e) { log.debug("can't send unavail icon: ", e); sendErrorIcon(request, response); } } protected void sendWarningIcon(HttpServletRequest request, HttpServletResponse response) { try { sendIcon(request, response, ICON_WARNING_URL); } catch (Exception e) { log.debug("can't send unavail icon: ", e); sendErrorIcon(request, response); } } protected void sendErrorIcon(HttpServletRequest request, HttpServletResponse response) { try { sendIcon(request, response, ICON_ERR_URL); return; } catch (Exception e) { log.debug("can't send error icon: ", e); } // if we made it this far, we can't even get the error icon // sent. bail out with an internal server error. try { response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); response.flushBuffer(); } catch (IOException e) { log.debug("can't commit server error response !? ", e); } } protected void sendPausedIcon(HttpServletRequest request, HttpServletResponse response) { try { sendIcon(request, response, ICON_PAUSED_URL); } catch (Exception e) { log.debug("can't send paused icon: ", e); sendErrorIcon(request, response); } } protected void sendPoweredOffIcon(HttpServletRequest request, HttpServletResponse response) { try { sendIcon(request, response, ICON_POWERED_OFF_URL); } catch (Exception e) { log.debug("can't send paused icon: ", e); sendErrorIcon(request, response); } } }