org.springframework.web.servlet.view.tiles.ComponentControllerSupport Maven / Gradle / Ivy
/*
* Copyright 2002-2005 the original author or authors.
*
* Licensed 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.springframework.web.servlet.view.tiles;
import java.io.File;
import java.io.IOException;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.tiles.ComponentContext;
import org.apache.struts.tiles.ControllerSupport;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.MessageSourceAccessor;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.servlet.support.RequestContextUtils;
import org.springframework.web.util.NestedServletException;
import org.springframework.web.util.WebUtils;
/**
* Convenience class for Spring-aware Tiles component controllers.
* Provides a reference to the current Spring application context,
* e.g. for bean lookup or resource loading.
*
* Derives from Tiles' ControllerSupport class rather than
* implementing Tiles' Controller interface to be compatible with
* Struts 1.1 and 1.2. Implements both Struts 1.1's perform
* and Struts 1.2's execute method accordingly.
*
* @author Juergen Hoeller
* @author Alef Arendsen
* @since 22.08.2003
* @see org.springframework.web.context.support.WebApplicationObjectSupport
*/
public abstract class ComponentControllerSupport extends ControllerSupport {
private WebApplicationContext webApplicationContext;
private MessageSourceAccessor messageSourceAccessor;
/**
* This implementation delegates to execute,
* converting non-Servlet/IO Exceptions to ServletException.
*
This is the only execution method available in Struts 1.1.
* @see #execute
*/
public final void perform(
ComponentContext componentContext, HttpServletRequest request,
HttpServletResponse response, ServletContext servletContext)
throws ServletException, IOException {
try {
execute(componentContext, request, response, servletContext);
}
catch (ServletException ex) {
throw ex;
}
catch (IOException ex) {
throw ex;
}
catch (Throwable ex) {
throw new NestedServletException("Execution of component controller failed", ex);
}
}
/**
* This implementation delegates to doPerform,
* lazy-initializing the application context reference if necessary.
*
This is the preferred execution method in Struts 1.2.
* When running with Struts 1.1, it will be called by perform.
* @see #perform
* @see #doPerform
*/
public final void execute(
ComponentContext componentContext, HttpServletRequest request,
HttpServletResponse response, ServletContext servletContext)
throws Exception {
synchronized (this) {
if (this.webApplicationContext == null) {
this.webApplicationContext = RequestContextUtils.getWebApplicationContext(request, servletContext);
this.messageSourceAccessor = new MessageSourceAccessor(this.webApplicationContext);
}
}
doPerform(componentContext, request, response);
}
/**
* Subclasses can override this for custom initialization behavior.
* Gets called on initialization of the context for this controller.
* @throws org.springframework.context.ApplicationContextException in case of initialization errors
* @throws org.springframework.beans.BeansException if thrown by application context methods
*/
protected void initApplicationContext() throws BeansException {
}
/**
* Return the current Spring ApplicationContext.
*/
protected final ApplicationContext getApplicationContext() {
return this.webApplicationContext;
}
/**
* Return the current Spring WebApplicationContext.
*/
protected final WebApplicationContext getWebApplicationContext() {
return this.webApplicationContext;
}
/**
* Return a MessageSourceAccessor for the application context
* used by this object, for easy message access.
*/
protected final MessageSourceAccessor getMessageSourceAccessor() {
return this.messageSourceAccessor;
}
/**
* Return the current ServletContext.
*/
protected final ServletContext getServletContext() {
return this.webApplicationContext.getServletContext();
}
/**
* Return the temporary directory for the current web application,
* as provided by the servlet container.
* @return the File representing the temporary directory
*/
protected final File getTempDir() {
return WebUtils.getTempDir(getServletContext());
}
/**
* Perform the preparation for the component, allowing for any Exception to be thrown.
* The ServletContext can be retrieved via getServletContext, if necessary.
* The Spring WebApplicationContext can be accessed via getWebApplicationContext.
*
This method will be called both in the Struts 1.1 and Struts 1.2 case,
* by perform or execute, respectively.
* @param componentContext current Tiles component context
* @param request current HTTP request
* @param response current HTTP response
* @throws Exception in case of errors
* @see org.apache.struts.tiles.Controller#perform
* @see #getServletContext
* @see #getWebApplicationContext
* @see #perform
* @see #execute
*/
protected abstract void doPerform(
ComponentContext componentContext, HttpServletRequest request, HttpServletResponse response)
throws Exception;
}