MvcRequestMatcher servletPath Polish / XML Config

Fixes gh-4014

web/src/main/java/org/springframework/security/web/servlet/util/matcher/MvcRequestMatcher.java

@@ -16,17 +16,24 @@
 
 package org.springframework.security.web.servlet.util.matcher;
 
+import org.springframework.beans.factory.InitializingBean;
 import org.springframework.http.HttpMethod;
+import org.springframework.security.web.access.intercept.FilterInvocationSecurityMetadataSource;
 import org.springframework.security.web.util.matcher.RequestMatcher;
 import org.springframework.security.web.util.matcher.RequestVariablesExtractor;
 import org.springframework.util.AntPathMatcher;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.PathMatcher;
+import org.springframework.web.context.ServletContextAware;
 import org.springframework.web.servlet.handler.HandlerMappingIntrospector;
 import org.springframework.web.servlet.handler.MatchableHandlerMapping;
 import org.springframework.web.servlet.handler.RequestMatchResult;
 import org.springframework.web.util.UrlPathHelper;
 
+import javax.servlet.ServletContext;
+import javax.servlet.ServletRegistration;
 import javax.servlet.http.HttpServletRequest;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
 
@@ -45,13 +52,18 @@ import java.util.Map;
  * @since 4.1.1
  */
 public class MvcRequestMatcher
-		implements RequestMatcher, RequestVariablesExtractor {
+		implements RequestMatcher, RequestVariablesExtractor, InitializingBean, ServletContextAware {
+
+	private static final boolean isServlet30 = ClassUtils.isPresent(
+		"javax.servlet.ServletRegistration", MvcRequestMatcher.class.getClassLoader());
+
 	private final DefaultMatcher defaultMatcher = new DefaultMatcher();
 
 	private final HandlerMappingIntrospector introspector;
 	private final String pattern;
 	private HttpMethod method;
 	private String servletPath;
+	private ServletContext servletContext;
 
 	public MvcRequestMatcher(HandlerMappingIntrospector introspector, String pattern) {
 		this.introspector = introspector;
@@ -100,6 +112,40 @@ public class MvcRequestMatcher
 				: result.extractUriTemplateVariables();
 	}
 
+	/* (non-Javadoc)
+	 * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
+	 */
+	@Override
+	public void afterPropertiesSet() throws Exception {
+		// servletPath is required when at least one registered Servlet
+		// is mapped to a path other than the default (root) path '/'
+		if (this.servletContext == null || !isServlet30) {
+			return;
+		}
+		if (this.getServletPath() != null) {
+			return;
+		}
+		for (ServletRegistration registration : this.servletContext.getServletRegistrations().values()) {
+			for (String mapping : registration.getMappings()) {
+				if (mapping.startsWith("/") && mapping.length() > 1) {
+					throw new IllegalStateException(
+						"servletPath must not be null for mvcPattern \"" + this.getMvcPattern()
+							+ "\" when providing a servlet mapping of "
+							+ mapping + " for servlet "
+							+ registration.getClassName());
+				}
+			}
+		}
+	}
+
+	/* (non-Javadoc)
+	 * @see org.springframework.web.context.ServletContextAware#setServletContext(javax.servlet.ServletContext)
+	 */
+	@Override
+	public void setServletContext(ServletContext servletContext) {
+		this.servletContext = servletContext;
+	}
+
 	/**
 	 * @param method the method to set
 	 */