/*
* Copyright 2002-2006 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.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionServlet;
import org.apache.struts.action.RequestProcessor;
import org.apache.struts.config.ModuleConfig;
import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.web.context.WebApplicationContext;
/**
* Subclass of Struts's default RequestProcessor that autowires Struts Actions
* with Spring beans defined in ContextLoaderPlugIn's WebApplicationContext
* or - in case of general service layer beans - in the root WebApplicationContext.
*
* <p>In the Struts config file, you simply continue to specify the original
* Action class. The instance created for that class will automatically get
* wired with matching service layer beans, that is, bean property setters
* will automatically be called if a service layer bean matches the property.
*
* <pre>
* <action path="/login" type="myapp.MyAction"/></pre>
*
* There are two autowire modes available: "byType" and "byName". The default
* is "byType", matching service layer beans with the Action's bean property
* argument types. This behavior can be changed through specifying an "autowire"
* init-param for the Struts ActionServlet with the value "byName", which will
* match service layer bean names with the Action's bean property <i>names</i>.
*
* <p>Dependency checking is turned off by default: If no matching service
* layer bean can be found, the setter in question will simply not get invoked.
* To enforce matching service layer beans, consider specify the "dependencyCheck"
* init-param for the Struts ActionServlet with the value "true".
*
* <p>If you also need the Tiles setup functionality of the original
* TilesRequestProcessor, use AutowiringTilesRequestProcessor. As there's just
* a single central class to customize in Struts, we have to provide another
* subclass here, covering both the Tiles and the Spring delegation aspect.
*
* <p>The default implementation delegates to the DelegatingActionUtils
* class as fas as possible, to reuse as much code as possible despite
* the need to provide two RequestProcessor subclasses. If you need to
* subclass yet another RequestProcessor, take this class as a template,
* delegating to DelegatingActionUtils just like it.
*
* @author Juergen Hoeller
* @since 2.0
* @see AutowiringTilesRequestProcessor
* @see ContextLoaderPlugIn
* @see DelegatingActionUtils
*/
public class AutowiringRequestProcessor extends RequestProcessor {
private WebApplicationContext webApplicationContext;
private int autowireMode = AutowireCapableBeanFactory.AUTOWIRE_NO;
private boolean dependencyCheck = false;
public void init(ActionServlet actionServlet, ModuleConfig moduleConfig) throws ServletException {
super.init(actionServlet, moduleConfig);
if (actionServlet != null) {
this.webApplicationContext = initWebApplicationContext(actionServlet, moduleConfig);
this.autowireMode = initAutowireMode(actionServlet, moduleConfig);
this.dependencyCheck = initDependencyCheck(actionServlet, moduleConfig);
}
}
/**
* Fetch ContextLoaderPlugIn's WebApplicationContext from the ServletContext,
* falling back to the root WebApplicationContext. This context is supposed
* to contain the service layer beans to wire the Struts Actions with.
* @param actionServlet the associated ActionServlet
* @param moduleConfig the associated ModuleConfig
* @return the WebApplicationContext
* @throws IllegalStateException if no WebApplicationContext could be found
* @see DelegatingActionUtils#findRequiredWebApplicationContext
* @see ContextLoaderPlugIn#SERVLET_CONTEXT_PREFIX
*/
protected WebApplicationContext initWebApplicationContext(
ActionServlet actionServlet, ModuleConfig moduleConfig) throws IllegalStateException {
WebApplicationContext wac =
DelegatingActionUtils.findRequiredWebApplicationContext(actionServlet, moduleConfig);
if (wac instanceof ConfigurableApplicationContext) {
((ConfigurableApplicationContext) wac).getBeanFactory().ignoreDependencyType(ActionServlet.class);
}
return wac;
}
/**
* Determine the autowire mode to use for wiring Struts Actions.
* <p>The default implementation checks the "autowire" init-param of the
* Struts ActionServlet, falling back to "AUTOWIRE_BY_TYPE" as default.
* @param actionServlet the associated ActionServlet
* @param moduleConfig the associated ModuleConfig
* @return the autowire mode to use
* @see DelegatingActionUtils#getAutowireMode
* @see org.springframework.beans.factory.config.AutowireCapableBeanFactory#autowireBeanProperties
* @see org.springframework.beans.factory.config.AutowireCapableBeanFactory#AUTOWIRE_BY_TYPE
* @see org.springframework.beans.factory.config.AutowireCapableBeanFactory#AUTOWIRE_BY_NAME
*/
protected int initAutowireMode(ActionServlet actionServlet, ModuleConfig moduleConfig) {
return DelegatingActionUtils.getAutowireMode(actionServlet);
}
/**
* Determine whether to apply a dependency check after wiring Struts Actions.
* <p>The default implementation checks the "dependencyCheck" init-param of the
* Struts ActionServlet, falling back to no dependency check as default.
* @param actionServlet the associated ActionServlet
* @param moduleConfig the associated ModuleConfig
* @return whether to enforce a dependency check or not
* @see DelegatingActionUtils#getDependencyCheck
* @see org.springframework.beans.factory.config.AutowireCapableBeanFactory#autowireBeanProperties
*/
protected boolean initDependencyCheck(ActionServlet actionServlet, ModuleConfig moduleConfig) {
return DelegatingActionUtils.getDependencyCheck(actionServlet);
}
/**
* Return the current Spring WebApplicationContext.
*/
protected final WebApplicationContext getWebApplicationContext() {
return this.webApplicationContext;
}
/**
* Return the autowire mode to use for wiring Struts Actions.
*/
protected final int getAutowireMode() {
return autowireMode;
}
/**
* Return whether to apply a dependency check after wiring Struts Actions.
*/
protected final boolean getDependencyCheck() {
return dependencyCheck;
}
/**
* Extend the base class method to autowire each created Action instance.
* @see org.springframework.beans.factory.config.AutowireCapableBeanFactory#autowireBeanProperties
*/
protected Action processActionCreate(
HttpServletRequest request, HttpServletResponse response, ActionMapping mapping)
throws IOException {
Action action = super.processActionCreate(request, response, mapping);
getWebApplicationContext().getAutowireCapableBeanFactory().autowireBeanProperties(
action, getAutowireMode(), getDependencyCheck());
return action;
}
}