/**
* 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.
*/
package org.apache.activemq.web.filter;
import java.io.IOException;
import java.util.AbstractMap;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.activemq.web.BrokerFacade;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
/**
* Exposes Spring ApplicationContexts to JSP EL and other view technologies.
* Currently a variable is placed in application scope (by default called
* 'applicationContext') so that POJOs can be pulled out of Spring in a JSP page
* to render things using EL expressions. <br/>
*
* e.g. ${applicationContext.cheese} would access the cheese POJO. Or
* ${applicationContext.cheese.name} would access the name property of the
* cheese POJO. <br/>
*
* You can then use JSTL to work with these POJOs such as <c.set var="myfoo"
* value="${applicationContext.foo}"/> <br/>
*
* In addition to applicationContext a 'requestContext' variable is created
* which will automatically bind any request parameters to the POJOs extracted
* from the applicationContext - which is ideal for POJOs which implement
* queries in view technologies.
*
*
*/
public class ApplicationContextFilter implements Filter {
private static final transient Logger LOG = LoggerFactory.getLogger(ApplicationContextFilter.class);
private ServletContext servletContext;
private String applicationContextName = "applicationContext";
private String requestContextName = "requestContext";
private String requestName = "request";
public void init(FilterConfig config) throws ServletException {
this.servletContext = config.getServletContext();
this.applicationContextName = getInitParameter(config, "applicationContextName", applicationContextName);
this.requestContextName = getInitParameter(config, "requestContextName", requestContextName);
this.requestName = getInitParameter(config, "requestName", requestName);
// register the application context in the applicationScope
WebApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(servletContext);
Map wrapper = createApplicationContextWrapper(context);
servletContext.setAttribute(applicationContextName, wrapper);
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
// lets register a requestContext in the requestScope
Map requestContextWrapper = createRequestContextWrapper(request);
String path = ((HttpServletRequest)request).getRequestURI();
// handle slave brokers
// try {
// if ( !(path.endsWith("css") || path.endsWith("png") || path.endsWith("ico") || path.endsWith(slavePage))
// && ((BrokerFacade)requestContextWrapper.get("brokerQuery")).isSlave()) {
// ((HttpServletResponse)response).sendRedirect(slavePage);
// return;
// }
// } catch (Exception e) {
// LOG.warn(path + ", failed to access BrokerFacade: reason: " + e.getLocalizedMessage());
// if (LOG.isDebugEnabled()) {
// LOG.debug(request.toString(), e);
// }
// throw new IOException(e);
// }
request.setAttribute(requestContextName, requestContextWrapper);
request.setAttribute(requestName, request);
chain.doFilter(request, response);
}
public void destroy() {
}
public ServletContext getServletContext() {
return servletContext;
}
public String getApplicationContextName() {
return applicationContextName;
}
public void setApplicationContextName(String variableName) {
this.applicationContextName = variableName;
}
public String getRequestContextName() {
return requestContextName;
}
public void setRequestContextName(String requestContextName) {
this.requestContextName = requestContextName;
}
protected String getInitParameter(FilterConfig config, String key, String defaultValue) {
String parameter = config.getInitParameter(key);
return (parameter != null) ? parameter : defaultValue;
}
/**
* Creates a wrapper around the web application context so that it can be
* accessed easily from inside JSP EL (or other expression languages in
* other view technologies).
*/
protected Map createApplicationContextWrapper(final WebApplicationContext context) {
Map wrapper = new AbstractMap() {
public WebApplicationContext getContext() {
return context;
}
public Object get(Object key) {
if (key == null) {
return null;
}
return context.getBean(key.toString());
}
public Set entrySet() {
return Collections.EMPTY_SET;
}
};
return wrapper;
}
/**
* Creates a wrapper around the request context (e.g. to allow POJOs to be
* auto-injected from request parameter values etc) so that it can be
* accessed easily from inside JSP EL (or other expression languages in
* other view technologies).
*/
protected Map createRequestContextWrapper(final ServletRequest request) {
final WebApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(servletContext);
Map wrapper = new AbstractMap() {
public WebApplicationContext getContext() {
return context;
}
public Object get(Object key) {
if (key == null) {
return null;
}
return bindRequestBean(context.getBean(key.toString()), request);
}
public Set entrySet() {
return Collections.EMPTY_SET;
}
};
return wrapper;
}
/**
* Binds properties from the request parameters to the given POJO which is
* useful for POJOs which are configurable via request parameters such as
* for query/view POJOs
*/
protected Object bindRequestBean(Object bean, ServletRequest request) {
ServletRequestDataBinder binder = new ServletRequestDataBinder(bean, null);
binder.bind(request);
return bean;
}
}