org.springframework.web.servlet.handler.HandlerMappingIntrospector Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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
*
* https://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.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.core.annotation.AnnotationAwareOrderComparator;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PropertiesLoaderUtils;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.CorsConfigurationSource;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.HandlerExecutionChain;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.HandlerMapping;
/**
* Helper class to get information from the {@code HandlerMapping} that would
* serve a specific request.
*
* Provides the following methods:
*
* - {@link #getMatchableHandlerMapping} — obtain a {@code HandlerMapping}
* to check request-matching criteria against.
*
- {@link #getCorsConfiguration} — obtain the CORS configuration for the
* request.
*
*
* @author Rossen Stoyanchev
* @since 4.3.1
*/
public class HandlerMappingIntrospector
implements CorsConfigurationSource, ApplicationContextAware, InitializingBean {
@Nullable
private ApplicationContext applicationContext;
@Nullable
private List handlerMappings;
/**
* Constructor for use with {@link ApplicationContextAware}.
*/
public HandlerMappingIntrospector() {
}
/**
* Constructor that detects the configured {@code HandlerMapping}s in the
* given {@code ApplicationContext} or falls back on
* "DispatcherServlet.properties" like the {@code DispatcherServlet}.
* @deprecated as of 4.3.12, in favor of {@link #setApplicationContext}
*/
@Deprecated
public HandlerMappingIntrospector(ApplicationContext context) {
this.handlerMappings = initHandlerMappings(context);
}
/**
* Return the configured HandlerMapping's.
*/
public List getHandlerMappings() {
return (this.handlerMappings != null ? this.handlerMappings : Collections.emptyList());
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
@Override
public void afterPropertiesSet() {
if (this.handlerMappings == null) {
Assert.notNull(this.applicationContext, "No ApplicationContext");
this.handlerMappings = initHandlerMappings(this.applicationContext);
}
}
/**
* Find the {@link HandlerMapping} that would handle the given request and
* return it as a {@link MatchableHandlerMapping} that can be used to test
* request-matching criteria.
* If the matching HandlerMapping is not an instance of
* {@link MatchableHandlerMapping}, an IllegalStateException is raised.
* @param request the current request
* @return the resolved matcher, or {@code null}
* @throws Exception if any of the HandlerMapping's raise an exception
*/
@Nullable
public MatchableHandlerMapping getMatchableHandlerMapping(HttpServletRequest request) throws Exception {
Assert.notNull(this.handlerMappings, "Handler mappings not initialized");
HttpServletRequest wrapper = new RequestAttributeChangeIgnoringWrapper(request);
for (HandlerMapping handlerMapping : this.handlerMappings) {
Object handler = handlerMapping.getHandler(wrapper);
if (handler == null) {
continue;
}
if (handlerMapping instanceof MatchableHandlerMapping) {
return ((MatchableHandlerMapping) handlerMapping);
}
throw new IllegalStateException("HandlerMapping is not a MatchableHandlerMapping");
}
return null;
}
@Override
@Nullable
public CorsConfiguration getCorsConfiguration(HttpServletRequest request) {
Assert.notNull(this.handlerMappings, "Handler mappings not initialized");
HttpServletRequest wrapper = new RequestAttributeChangeIgnoringWrapper(request);
for (HandlerMapping handlerMapping : this.handlerMappings) {
HandlerExecutionChain handler = null;
try {
handler = handlerMapping.getHandler(wrapper);
}
catch (Exception ex) {
// Ignore
}
if (handler == null) {
continue;
}
if (handler.getInterceptors() != null) {
for (HandlerInterceptor interceptor : handler.getInterceptors()) {
if (interceptor instanceof CorsConfigurationSource) {
return ((CorsConfigurationSource) interceptor).getCorsConfiguration(wrapper);
}
}
}
if (handler.getHandler() instanceof CorsConfigurationSource) {
return ((CorsConfigurationSource) handler.getHandler()).getCorsConfiguration(wrapper);
}
}
return null;
}
private static List initHandlerMappings(ApplicationContext applicationContext) {
Map beans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
applicationContext, HandlerMapping.class, true, false);
if (!beans.isEmpty()) {
List mappings = new ArrayList<>(beans.values());
AnnotationAwareOrderComparator.sort(mappings);
return Collections.unmodifiableList(mappings);
}
return Collections.unmodifiableList(initFallback(applicationContext));
}
private static List initFallback(ApplicationContext applicationContext) {
Properties props;
String path = "DispatcherServlet.properties";
try {
Resource resource = new ClassPathResource(path, DispatcherServlet.class);
props = PropertiesLoaderUtils.loadProperties(resource);
}
catch (IOException ex) {
throw new IllegalStateException("Could not load '" + path + "': " + ex.getMessage());
}
String value = props.getProperty(HandlerMapping.class.getName());
String[] names = StringUtils.commaDelimitedListToStringArray(value);
List result = new ArrayList<>(names.length);
for (String name : names) {
try {
Class clazz = ClassUtils.forName(name, DispatcherServlet.class.getClassLoader());
Object mapping = applicationContext.getAutowireCapableBeanFactory().createBean(clazz);
result.add((HandlerMapping) mapping);
}
catch (ClassNotFoundException ex) {
throw new IllegalStateException("Could not find default HandlerMapping [" + name + "]");
}
}
return result;
}
/**
* Request wrapper that ignores request attribute changes.
*/
private static class RequestAttributeChangeIgnoringWrapper extends HttpServletRequestWrapper {
public RequestAttributeChangeIgnoringWrapper(HttpServletRequest request) {
super(request);
}
@Override
public void setAttribute(String name, Object value) {
// Ignore attribute change...
}
}
}