Add throwExceptionIfNoHandlerFound property

Add a property to customize if an exception should be thrown when no
handler was found to process a given request.

Closes gh-4000

Author: snicoll

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/DispatcherServletAutoConfiguration.java

@@ -34,6 +34,7 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
 import org.springframework.boot.context.embedded.ServletRegistrationBean;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.context.web.SpringBootServletInitializer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ConditionContext;
@@ -53,6 +54,7 @@
  *
  * @author Phillip Webb
  * @author Dave Syer
+ * @author Stephane Nicoll
  */
 @AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
 @Configuration
@@ -74,17 +76,24 @@ public class DispatcherServletAutoConfiguration {
 	@Configuration
 	@Conditional(DefaultDispatcherServletCondition.class)
 	@ConditionalOnClass(ServletRegistration.class)
+	@EnableConfigurationProperties(WebMvcProperties.class)
 	protected static class DispatcherServletConfiguration {
 
 		@Autowired
 		private ServerProperties server;
 
+		@Autowired
+		private WebMvcProperties webMvcProperties;
+
 		@Autowired(required = false)
 		private MultipartConfigElement multipartConfig;
 
 		@Bean(name = DEFAULT_DISPATCHER_SERVLET_BEAN_NAME)
 		public DispatcherServlet dispatcherServlet() {
-			return new DispatcherServlet();
+			DispatcherServlet dispatcherServlet = new DispatcherServlet();
+			dispatcherServlet.setThrowExceptionIfNoHandlerFound(
+					this.webMvcProperties.isThrowExceptionIfNoHandlerFound());
+			return dispatcherServlet;
 		}
 
 		@Bean(name = DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME)

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcProperties.java

@@ -53,6 +53,12 @@ public class WebMvcProperties {
 	 */
 	private boolean ignoreDefaultModelOnRedirect = true;
 
+	/**
+	 * If a "NoHandlerFoundException" should be thrown if no Handler was found to process
+	 * a request.
+	 */
+	private boolean throwExceptionIfNoHandlerFound = false;
+
 	private final Async async = new Async();
 
 	private final View view = new View();
@@ -90,6 +96,14 @@ public void setIgnoreDefaultModelOnRedirect(boolean ignoreDefaultModelOnRedirect
 		this.ignoreDefaultModelOnRedirect = ignoreDefaultModelOnRedirect;
 	}
 
+	public boolean isThrowExceptionIfNoHandlerFound() {
+		return this.throwExceptionIfNoHandlerFound;
+	}
+
+	public void setThrowExceptionIfNoHandlerFound(boolean throwExceptionIfNoHandlerFound) {
+		this.throwExceptionIfNoHandlerFound = throwExceptionIfNoHandlerFound;
+	}
+
 	public Async getAsync() {
 		return this.async;
 	}

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/DispatcherServletAutoConfigurationTests.java

@@ -19,7 +19,9 @@
 import javax.servlet.MultipartConfigElement;
 import javax.servlet.http.HttpServletRequest;
 
+import org.junit.After;
 import org.junit.Test;
+import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.beans.factory.UnsatisfiedDependencyException;
 import org.springframework.boot.context.embedded.MultipartConfigFactory;
 import org.springframework.boot.context.embedded.ServletRegistrationBean;
@@ -49,6 +51,13 @@ public class DispatcherServletAutoConfigurationTests {
 
 	private AnnotationConfigWebApplicationContext context;
 
+	@After
+	public void closeContext() {
+		if (this.context != null) {
+			this.context.close();
+		}
+	}
+
 	@Test
 	public void registrationProperties() throws Exception {
 		this.context = new AnnotationConfigWebApplicationContext();
@@ -137,6 +146,20 @@ public void renamesMultipartResolver() throws Exception {
 				instanceOf(MockMultipartResolver.class));
 	}
 
+	@Test
+	public void dispatcherServletConfig() {
+		this.context = new AnnotationConfigWebApplicationContext();
+		this.context.setServletContext(new MockServletContext());
+		this.context.register(ServerPropertiesAutoConfiguration.class,
+				DispatcherServletAutoConfiguration.class);
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.mvc.throw-exception-if-no-handler-found:true");
+		this.context.refresh();
+		DispatcherServlet bean = this.context.getBean(DispatcherServlet.class);
+		assertEquals(true, new DirectFieldAccessor(bean).
+				getPropertyValue("throwExceptionIfNoHandlerFound"));
+	}
+
 	@Configuration
 	protected static class MultipartConfiguration {
 

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -151,6 +151,7 @@ content into your application; rather pick only the properties that you need.
 	spring.mvc.favicon.enabled=true
 	spring.mvc.message-codes-resolver-format= # PREFIX_ERROR_CODE / POSTFIX_ERROR_CODE
 	spring.mvc.ignore-default-model-on-redirect=true # if the content of the "default" model should be ignored redirects
+	spring.mvc.throw-exception-if-no-handler-found=false # if a "NoHandlerFoundException" should be thrown if no Handler was found to process a request
 	spring.mvc.async.request-timeout= # async request timeout in milliseconds
 	spring.mvc.view.prefix= # MVC view prefix
 	spring.mvc.view.suffix= # ... and suffix