org.springframework.web.servlet.handler.metadata.CommonsPathMapHandlerMapping 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.handler.metadata;
import java.util.Collection;
import org.apache.commons.attributes.AttributeIndex;
import org.apache.commons.attributes.Attributes;
/**
* Subclass of AbstractPathMapHandlerMapping that recognizes Commons Attributes
* metadata attributes of type PathMap on application Controllers and automatically
* wires them into the current servlet's WebApplicationContext.
*
*
* Controllers must have class attributes of the form:
*
* &64;org.springframework.web.servlet.handler.commonsattributes.PathMap("/path.cgi")
*
*
*
The path must be mapped to the relevant Spring DispatcherServlet in /WEB-INF/web.xml.
* It's possible to have multiple PathMap attributes on the one controller class.
*
*
To use this feature, you must compile application classes with Commons Attributes,
* and run the Commons Attributes indexer tool on your application classes, which must
* be in a Jar rather than in WEB-INF/classes.
*
*
Controllers instantiated by this class may have dependencies on middle tier
* objects, expressed via JavaBean properties or constructor arguments. These will
* be resolved automatically.
*
*
You will normally use this HandlerMapping with at most one DispatcherServlet in
* your web application. Otherwise you'll end with one instance of the mapped controller
* for each DispatcherServlet's context. You might want this--for example, if
* one's using a .pdf mapping and a PDF view, and another a JSP view, or if using
* different middle tier objects, but should understand the implications. All
* Controllers with attributes will be picked up by each DispatcherServlet's context.
*
* @author Rod Johnson
* @author Juergen Hoeller
*/
public class CommonsPathMapHandlerMapping extends AbstractPathMapHandlerMapping {
/**
* Use Commons Attributes AttributeIndex to get a Collection of Class
* objects with the required PathMap attribute. Protected so that it can
* be overridden during testing.
*/
protected Class[] getClassesWithPathMapAttributes() throws Exception {
AttributeIndex ai = new AttributeIndex(getClass().getClassLoader());
Collection classes = ai.getClasses(PathMap.class);
return (Class[]) classes.toArray(new Class[classes.size()]);
}
/**
* Use Commons Attributes to find PathMap attributes for the given class.
* We know there's at least one, as the getClassNamesWithPathMapAttributes
* method return this class name.
*/
protected PathMap[] getPathMapAttributes(Class handlerClass) {
Collection atts = Attributes.getAttributes(handlerClass, PathMap.class);
return (PathMap[]) atts.toArray(new PathMap[atts.size()]);
}
}