org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping Maven / Gradle / Ivy
/*
* Copyright 2002-2007 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;
import java.util.ArrayList;
import java.util.List;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.context.ApplicationContextException;
import org.springframework.util.StringUtils;
/**
* Implementation of the {@link org.springframework.web.servlet.HandlerMapping}
* interface that map from URLs to beans with names that start with a slash ("/"),
* similar to how Struts maps URLs to action names.
*
* This is the default implementation used by the
* {@link org.springframework.web.servlet.DispatcherServlet}, but it is somewhat naive.
* A {@link SimpleUrlHandlerMapping} or a custom handler mapping should be used
* by preference.
*
*
The mapping is from URL to bean name. Thus an incoming URL "/foo" would map
* to a handler named "/foo", or to "/foo /foo2" in case of multiple mappings to
* a single handler. Note: In XML definitions, you'll need to use an alias
* name="/foo" in the bean definition, as the XML id may not contain slashes.
*
*
Supports direct matches (given "/test" -> registered "/test") and "*"
* matches (given "/test" -> registered "/t*"). Note that the default is
* to map within the current servlet mapping if applicable; see the
* {@link #setAlwaysUseFullPath "alwaysUseFullPath"} property for details.
* For details on the pattern options, see the
* {@link org.springframework.util.AntPathMatcher} javadoc.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @see SimpleUrlHandlerMapping
*/
public class BeanNameUrlHandlerMapping extends AbstractUrlHandlerMapping {
private boolean detectHandlersInAncestorContexts = false;
/**
* Set whether to detect handler beans in ancestor ApplicationContexts.
*
Default is "false": Only handler beans in the current
* ApplicationContext will be detected, that is, only in the context
* that this BeanNameUrlHandlerMapping itself is defined in (typically
* the current DispatcherServlet's context).
*
Switch this flag on to detect handler beans in ancestor contexts
* (typically the Spring root WebApplicationContext) as well.
*/
public void setDetectHandlersInAncestorContexts(boolean detectHandlersInAncestorContexts) {
this.detectHandlersInAncestorContexts = detectHandlersInAncestorContexts;
}
/**
* Calls the {@link #detectHandlers()} method in addition to the
* superclass's initialization.
*/
public void initApplicationContext() throws ApplicationContextException {
super.initApplicationContext();
detectHandlers();
}
/**
* Register all handlers found in the current ApplicationContext.
* Any bean whose name appears to be a URL is considered a handler.
* @throws BeansException if the handler couldn't be registered
* @see #determineUrlsForHandler
*/
protected void detectHandlers() throws BeansException {
if (logger.isDebugEnabled()) {
logger.debug("Looking for URL mappings in application context: " + getApplicationContext());
}
String[] beanNames = (this.detectHandlersInAncestorContexts ?
BeanFactoryUtils.beanNamesForTypeIncludingAncestors(getApplicationContext(), Object.class) :
getApplicationContext().getBeanNamesForType(Object.class));
// Take any bean name or alias that begins with a slash.
for (int i = 0; i < beanNames.length; i++) {
String beanName = beanNames[i];
String[] urls = determineUrlsForHandler(beanName);
if (urls.length > 0) {
// URL paths found: Let's consider it a handler.
registerHandler(urls, beanName);
}
else {
if (logger.isDebugEnabled()) {
logger.debug("Rejected bean name '" + beanNames[i] + "': no URL paths identified");
}
}
}
}
/**
* Check name and aliases of the given bean for URLs,
* detected by starting with "/".
* @param beanName the name of the candidate bean
* @return the URLs determined for the bean, or an empty array if none
*/
protected String[] determineUrlsForHandler(String beanName) {
List urls = new ArrayList();
if (beanName.startsWith("/")) {
urls.add(beanName);
}
String[] aliases = getApplicationContext().getAliases(beanName);
for (int j = 0; j < aliases.length; j++) {
if (aliases[j].startsWith("/")) {
urls.add(aliases[j]);
}
}
return StringUtils.toStringArray(urls);
}
}