package org.apache.jcs.admin.servlet;
/*
* 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 javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.jcs.admin.JCSAdminBean;
import org.apache.velocity.Template;
import org.apache.velocity.context.Context;
import org.apache.velocity.servlet.VelocityServlet;
/**
* A servlet which provides HTTP access to JCS. Allows a summary of regions to
* be viewed, and removeAll to be run on individual regions or all regions. Also
* provides the ability to remove items (any number of key arguments can be
* provided with action 'remove'). Should be initialized with a properties file
* that provides at least a classpath resource loader. Since this extends
* VelocityServlet, which uses the singleton model for velocity, it will share
* configuration with any other Velocity in the same JVM.
* <p>
* Initialization in a webapp will look something like this:
* <p>
*
* <pre>
*
* [servlet]
* [servlet-name]JCSAdminServlet[/servlet-name]
* [servlet-class]org.apache.jcs.admin.servlet.JCSAdminServlet[/servlet-class]
* [init-param]
* [param-name]properties[/param-name]
* [param-value]WEB-INF/conf/JCSAdminServlet.velocity.properties[/param-value]
* [/init-param]
* [/servlet]
*
* </pre>
*
* <p>
* FIXME: It would be nice to use the VelocityEngine model so this can be truly
* standalone. Right now if you run it in the same container as, say, turbine,
* turbine must be run first to ensure it's config takes precedence.
* <p>
*/
public class JCSAdminServlet
extends VelocityServlet
{
private static final long serialVersionUID = -5519844149238645275L;
private static final String DEFAULT_TEMPLATE_NAME = "/org/apache/jcs/admin/servlet/JCSAdminServletDefault.vm";
private static final String REGION_DETAIL_TEMPLATE_NAME = "/org/apache/jcs/admin/servlet/JCSAdminServletRegionDetail.vm";
// Keys for parameters
private static final String CACHE_NAME_PARAM = "cacheName";
private static final String ACTION_PARAM = "action";
private static final String KEY_PARAM = "key";
private static final String SILENT_PARAM = "silent";
// Possible values for 'action' parameter
private static final String CLEAR_ALL_REGIONS_ACTION = "clearAllRegions";
private static final String CLEAR_REGION_ACTION = "clearRegion";
private static final String REMOVE_ACTION = "remove";
private static final String DETAIL_ACTION = "detail";
/**
* Velocity based admin servlet.
* <p>
* @param request
* @param response
* @param context
* @return Template
* @throws Exception
*
*/
protected Template handleRequest( HttpServletRequest request, HttpServletResponse response, Context context )
throws Exception
{
JCSAdminBean admin = new JCSAdminBean();
String templateName = DEFAULT_TEMPLATE_NAME;
// Get cacheName for actions from request (might be null)
String cacheName = request.getParameter( CACHE_NAME_PARAM );
// If an action was provided, handle it
String action = request.getParameter( ACTION_PARAM );
if ( action != null )
{
if ( action.equals( CLEAR_ALL_REGIONS_ACTION ) )
{
admin.clearAllRegions();
}
else if ( action.equals( CLEAR_REGION_ACTION ) )
{
if ( cacheName != null )
{
admin.clearRegion( cacheName );
}
}
else if ( action.equals( REMOVE_ACTION ) )
{
String[] keys = request.getParameterValues( KEY_PARAM );
for ( int i = 0; i < keys.length; i++ )
{
admin.removeItem( cacheName, keys[i] );
}
templateName = REGION_DETAIL_TEMPLATE_NAME;
}
else if ( action.equals( DETAIL_ACTION ) )
{
templateName = REGION_DETAIL_TEMPLATE_NAME;
}
}
if ( request.getParameter( SILENT_PARAM ) != null )
{
// If silent parameter was passed, no output should be produced.
return null;
}
// Populate the context based on the template
if ( templateName == REGION_DETAIL_TEMPLATE_NAME )
{
context.put( "cacheName", cacheName );
context.put( "elementInfoRecords", admin.buildElementInfo( cacheName ) );
}
else if ( templateName == DEFAULT_TEMPLATE_NAME )
{
context.put( "cacheInfoRecords", admin.buildCacheInfo() );
}
return getTemplate( templateName );
}
}