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Diffstat (limited to 'spring-webmvc/src/main/java/org/springframework/web/servlet/handler/HandlerMappingIntrospector.java')
-rw-r--r-- | spring-webmvc/src/main/java/org/springframework/web/servlet/handler/HandlerMappingIntrospector.java | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/spring-webmvc/src/main/java/org/springframework/web/servlet/handler/HandlerMappingIntrospector.java b/spring-webmvc/src/main/java/org/springframework/web/servlet/handler/HandlerMappingIntrospector.java new file mode 100644 index 00000000..1c7fa9b6 --- /dev/null +++ b/spring-webmvc/src/main/java/org/springframework/web/servlet/handler/HandlerMappingIntrospector.java @@ -0,0 +1,187 @@ +/* + * Copyright 2002-2016 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.io.IOException; +import java.util.ArrayList; +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.context.ApplicationContext; +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.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. + * + * <p>Provides the following methods: + * <ul> + * <li>{@link #getMatchableHandlerMapping} — obtain a {@code HandlerMapping} + * to check request-matching criteria against. + * <li>{@link #getCorsConfiguration} — obtain the CORS configuration for the + * request. + * </ul> + * + * @author Rossen Stoyanchev + * @since 4.3.1 + */ +public class HandlerMappingIntrospector implements CorsConfigurationSource { + + private final List<HandlerMapping> handlerMappings; + + + /** + * Constructor that detects the configured {@code HandlerMapping}s in the + * given {@code ApplicationContext} or falls back on + * "DispatcherServlet.properties" like the {@code DispatcherServlet}. + */ + public HandlerMappingIntrospector(ApplicationContext context) { + this.handlerMappings = initHandlerMappings(context); + } + + + private static List<HandlerMapping> initHandlerMappings(ApplicationContext context) { + Map<String, HandlerMapping> beans = BeanFactoryUtils.beansOfTypeIncludingAncestors( + context, HandlerMapping.class, true, false); + if (!beans.isEmpty()) { + List<HandlerMapping> mappings = new ArrayList<HandlerMapping>(beans.values()); + AnnotationAwareOrderComparator.sort(mappings); + return mappings; + } + return initDefaultHandlerMappings(context); + } + + private static List<HandlerMapping> initDefaultHandlerMappings(ApplicationContext context) { + 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<HandlerMapping> result = new ArrayList<HandlerMapping>(names.length); + for (String name : names) { + try { + Class<?> clazz = ClassUtils.forName(name, DispatcherServlet.class.getClassLoader()); + Object mapping = context.getAutowireCapableBeanFactory().createBean(clazz); + result.add((HandlerMapping) mapping); + } + catch (ClassNotFoundException ex) { + throw new IllegalStateException("Could not find default HandlerMapping [" + name + "]"); + } + } + return result; + } + + + /** + * Return the configured HandlerMapping's. + */ + public List<HandlerMapping> getHandlerMappings() { + return this.handlerMappings; + } + + /** + * 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. + * <p>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 + */ + public MatchableHandlerMapping getMatchableHandlerMapping(HttpServletRequest request) throws Exception { + 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 + public CorsConfiguration getCorsConfiguration(HttpServletRequest request) { + 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; + } + + + /** + * 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 + } + } + +} |