package org.apache.commons.jcs3.auxiliary.remote.server;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import java.io.IOException;
  import java.io.OutputStream;
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  import java.nio.charset.StandardCharsets;
  import java.util.Properties;
  
  import javax.servlet.ServletConfig;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.jcs3.access.exception.CacheException;
  import org.apache.commons.jcs3.auxiliary.remote.RemoteUtils;
  import org.apache.commons.jcs3.engine.control.CompositeCacheManager;
  import org.apache.commons.jcs3.log.Log;
  import org.apache.commons.jcs3.log.LogManager;
  import org.apache.commons.jcs3.utils.net.HostNameUtil;
  
  /**
   * This servlet can be used to startup the JCS remote cache. It is easy to
   * deploy the remote server in a tomcat base. This give you an easy way to
   * monitor its activity.
   * <p>
   * <code>
   *  servlet&gt;
          &lt;servlet-name&gt;JCSRemoteCacheStartupServlet&lt;/servlet-name&gt;
          &lt;servlet-class&gt;
               org.apache.commons.jcs3.auxiliary.remote.server.RemoteCacheStartupServlet
          &lt;/servlet-class&gt;
          &lt;load-on-startup&gt;1&lt;/load-on-startup&gt;
      &lt;/servlet&gt;
  
  
      &lt;servlet-mapping&gt;
          &lt;servlet-name&gt;JCSRemoteCacheStartupServlet&lt;/servlet-name&gt;
          &lt;url-pattern&gt;/jcs&lt;/url-pattern&gt;
      &lt;/servlet-mapping&gt;
   * </code>
   */
  public class RemoteCacheStartupServlet
          extends HttpServlet
  {
      /** Don't change */
      private static final long serialVersionUID = 1L;
  
      /** The logger */
      private static final Log log = LogManager.getLog(RemoteCacheStartupServlet.class);
  
      /** The default port to start the registry on. */
      private static final int DEFAULT_REGISTRY_PORT = 1101;
  
      /** properties file name */
      private static final String DEFAULT_PROPS_FILE_NAME = "/cache.ccf";
  
      /** properties file name, must set prior to calling get instance */
      private String propsFileName = DEFAULT_PROPS_FILE_NAME;
  
      /** Configuration properties */
      private int registryPort = DEFAULT_REGISTRY_PORT;
  
      /** Configuration properties */
      private String registryHost;
  
      /**
       * Starts the registry and then tries to bind to it.
       * <p>
       * Gets the port from a props file. Uses the local host name for the
       * registry host. Tries to start the registry, ignoring failure. Starts the
       * server.
       * <p>
       *
       * @throws ServletException
       */
      @Override
      public void init()
              throws ServletException
     {
         super.init();
 
         loadInitParams();
         final Properties props = loadPropertiesFromFile();
 
         if (registryHost == null)
         {
             // we will always use the local machine for the registry
             try
             {
                 registryHost = HostNameUtil.getLocalHostAddress();
             }
             catch (final UnknownHostException e)
             {
                 log.error("Could not get local address to use for the registry!", e);
             }
         }
 
         log.debug("registryHost = [{0}]", registryHost);
 
         try
         {
             if (InetAddress.getByName(registryHost).isLoopbackAddress())
             {
                 log.warn("The local address [{0}] is a loopback address. Other machines must "
                         + "be able to use the address to reach this server.", registryHost);
             }
         }
         catch (final UnknownHostException e)
         {
             throw new ServletException("Could not resolve registry host " + registryHost, e);
         }
 
         try
         {
             if (props == null)
             {
                 throw new ServletException("Could not load configuration from " + propsFileName);
             }
 
             RemoteCacheServerFactory.startup(registryHost, registryPort, props);
             log.info("Remote JCS Server started with properties from {0}", propsFileName);
         }
         catch (final IOException e)
         {
             throw new ServletException("Problem starting remote cache server.", e);
         }
     }
 
     /**
      * It just dumps the stats.
      * <p>
      *
      * @param request
      * @param response
      * @throws ServletException
      * @throws IOException
      */
     @Override
     protected void service(final HttpServletRequest request, final HttpServletResponse response)
             throws ServletException, IOException
     {
         String stats = "";
 
         try
         {
             stats = CompositeCacheManager.getInstance().getStats();
         }
         catch (final CacheException e)
         {
             throw new ServletException(e);
         }
 
         log.info(stats);
 
         try
         {
             String characterEncoding = response.getCharacterEncoding();
             if (characterEncoding == null)
             {
                 characterEncoding = StandardCharsets.UTF_8.name();
                 response.setCharacterEncoding(characterEncoding);
             }
             final OutputStream os = response.getOutputStream();
             os.write(stats.getBytes(characterEncoding));
             os.close();
         }
         catch (final IOException e)
         {
             log.error("Problem writing response.", e);
         }
     }
 
     /**
      * shuts the cache down.
      */
     @Override
     public void destroy()
     {
         super.destroy();
 
         log.info("Shutting down remote cache ");
 
         try
         {
             RemoteCacheServerFactory.shutdownImpl(registryHost, registryPort);
         }
         catch (final IOException e)
         {
             log.error("Problem shutting down.", e);
         }
 
         try
         {
             CompositeCacheManager.getInstance().shutDown();
         }
         catch (final CacheException e)
         {
             log.error("Could not retrieve cache manager instance", e);
         }
     }
 
     /**
      * Load configuration values from config file if possible
      */
     private Properties loadPropertiesFromFile()
     {
         Properties props = null;
 
         try
         {
             props = RemoteUtils.loadProps(propsFileName);
             registryHost = props.getProperty("registry.host", registryHost);
             final String portS = props.getProperty("registry.port", String.valueOf(registryPort));
             setRegistryPort(portS);
         }
         catch (final IOException e)
         {
             log.error("Problem loading props.", e);
         }
 
         return props;
     }
 
     /**
      * Load configuration values from init params if possible
      */
     private void loadInitParams()
     {
         final ServletConfig config = getServletConfig();
         final String _propsFileName = config.getInitParameter("propsFileName");
         if (null != _propsFileName)
         {
             this.propsFileName = _propsFileName;
         }
         final String _registryHost = config.getInitParameter("registryHost");
         if (null != _registryHost)
         {
             this.registryHost = _registryHost;
         }
         final String regPortString = config.getInitParameter("registryPort");
         if (null != regPortString)
         {
             setRegistryPort(regPortString);
         }
     }
 
     /**
      * Set registry port from string If the string cannot be parsed, the default
      * value is used
      *
      * @param portS
      */
     private void setRegistryPort(final String portS)
     {
         try
         {
             this.registryPort = Integer.parseInt(portS);
         }
         catch (final NumberFormatException e)
         {
             log.error("Problem converting port to an int.", e);
             this.registryPort = DEFAULT_REGISTRY_PORT;
         }
     }
 }