org.springframework.web.struts.LookupDispatchActionSupport 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.struts;
import java.io.File;
import javax.servlet.ServletContext;
import org.apache.struts.action.ActionServlet;
import org.apache.struts.actions.LookupDispatchAction;
import org.springframework.context.support.MessageSourceAccessor;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.util.WebUtils;
/**
* Convenience class for Spring-aware Struts 1.1+ LookupDispatchActions.
*
* Provides a reference to the current Spring application context, e.g.
* for bean lookup or resource loading. Auto-detects a ContextLoaderPlugIn
* context, falling back to the root WebApplicationContext. For typical
* usage, i.e. accessing middle tier beans, use a root WebApplicationContext.
*
*
For classic Struts Actions, DispatchActions or MappingDispatchActions,
* use the analogous {@link ActionSupport ActionSupport} or
* {@link DispatchActionSupport DispatchActionSupport} /
* {@link MappingDispatchActionSupport MappingDispatchActionSupport} class.
*
*
As an alternative approach, you can wire your Struts Actions themselves
* as Spring beans, passing references to them via IoC rather than looking
* up references in a programmatic fashion. Check out
* {@link DelegatingActionProxy DelegatingActionProxy} and
* {@link DelegatingRequestProcessor DelegatingRequestProcessor}.
*
* @author Juergen Hoeller
* @since 1.1
* @see ContextLoaderPlugIn#SERVLET_CONTEXT_PREFIX
* @see WebApplicationContext#ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE
* @see org.springframework.web.context.ContextLoaderListener
* @see org.springframework.web.context.ContextLoaderServlet
* @see ActionSupport
* @see DispatchActionSupport
* @see MappingDispatchActionSupport
* @see DelegatingActionProxy
* @see DelegatingRequestProcessor
*/
public abstract class LookupDispatchActionSupport extends LookupDispatchAction {
private WebApplicationContext webApplicationContext;
private MessageSourceAccessor messageSourceAccessor;
/**
* Initialize the WebApplicationContext for this Action.
* Invokes onInit after successful initialization of the context.
* @see #initWebApplicationContext
* @see #onInit
*/
public void setServlet(ActionServlet actionServlet) {
super.setServlet(actionServlet);
if (actionServlet != null) {
this.webApplicationContext = initWebApplicationContext(actionServlet);
this.messageSourceAccessor = new MessageSourceAccessor(this.webApplicationContext);
onInit();
}
else {
onDestroy();
}
}
/**
* Fetch ContextLoaderPlugIn's WebApplicationContext from the ServletContext,
* falling back to the root WebApplicationContext (the usual case).
* @param actionServlet the associated ActionServlet
* @return the WebApplicationContext
* @throws IllegalStateException if no WebApplicationContext could be found
* @see DelegatingActionUtils#findRequiredWebApplicationContext
*/
protected WebApplicationContext initWebApplicationContext(ActionServlet actionServlet)
throws IllegalStateException {
return DelegatingActionUtils.findRequiredWebApplicationContext(actionServlet, null);
}
/**
* 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());
}
/**
* Callback for custom initialization after the context has been set up.
* @see #setServlet
*/
protected void onInit() {
}
/**
* Callback for custom destruction when the ActionServlet shuts down.
* @see #setServlet
*/
protected void onDestroy() {
}
}