[BS-157] Add MultipartConfig support

Use Servlet 3.0 features to autodetect a MultipartConfigElement and
hence autowire multipart support in the servlet container.

spring-bootstrap/src/main/java/org/springframework/bootstrap/autoconfigure/web/MultipartAutoConfiguration.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2012-2013 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.bootstrap.autoconfigure.web;
+
+import javax.servlet.MultipartConfigElement;
+
+import org.springframework.bootstrap.context.annotation.ConditionalOnBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.multipart.support.StandardServletMultipartResolver;
+
+/**
+ * Autoconfiguration for multipart uploads. It detects the existence of a
+ * {@link MultipartConfigElement} in the app context and then adds critical beans
+ * while also autowiring it into the Jetty/Tomcat embedded containers.
+ * 
+ * @author Greg Turnquist
+ *
+ */
+@Configuration
+public class MultipartAutoConfiguration {
+	
+	@ConditionalOnBean(MultipartConfigElement.class)
+	@Bean
+	public StandardServletMultipartResolver multipartResolver() {
+		System.out.println("Loading up a MultipartResolver!!!");
+	    return new StandardServletMultipartResolver();
+	}
+
+}

spring-bootstrap/src/main/java/org/springframework/bootstrap/context/embedded/EmbeddedServletContainerFactory.java

@@ -41,6 +41,6 @@ public interface EmbeddedServletContainerFactory {
 	 * @see EmbeddedServletContainer#stop()
 	 */
 	EmbeddedServletContainer getEmbdeddedServletContainer(
-			ServletContextInitializer... initializers);
+			ServletContextInitializer... initializers); //TODO(6/14/2013) Fix name of method
 
 }

spring-bootstrap/src/main/java/org/springframework/bootstrap/context/embedded/EmbeddedWebApplicationContext.java

@@ -23,10 +23,12 @@ import java.util.Comparator;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 
 import javax.servlet.Filter;
+import javax.servlet.MultipartConfigElement;
 import javax.servlet.Servlet;
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletContext;
@@ -208,10 +210,17 @@ public class EmbeddedWebApplicationContext extends GenericWebApplicationContext
 			}
 			initializers.add(initializer);
 		}
+		
+		Map<String, MultipartConfigElement> multipartConfigBeans;
+		MultipartConfigElement multipartConfigElement = null;
+		multipartConfigBeans = getBeanFactory().getBeansOfType(MultipartConfigElement.class);
+		for (MultipartConfigElement bean : multipartConfigBeans.values()) {
+			multipartConfigElement = bean;
+		}
 
 		List<Entry<String, Servlet>> servletBeans = getOrderedBeansOfType(Servlet.class);
 		for (Entry<String, Servlet> servletBean : servletBeans) {
-			String name = servletBean.getKey();
+			final String name = servletBean.getKey();
 			Servlet servlet = servletBean.getValue();
 			if (targets.contains(servlet)) {
 				continue;
@@ -220,10 +229,15 @@ public class EmbeddedWebApplicationContext extends GenericWebApplicationContext
 			if (name.equals(DISPATCHER_SERVLET_NAME)) {
 				url = "/"; // always map the main dispatcherServlet to "/"
 			}
-			ServletRegistrationBean registration = new ServletRegistrationBean(servlet,
+			if (multipartConfigElement != null) {
-					url);
+				initializers.add(new ServletRegistrationBean(servlet, multipartConfigElement, url) {{
-			registration.setName(name);
+					setName(name);
-			initializers.add(registration);
+				}});
+			} else {
+				initializers.add(new ServletRegistrationBean(servlet, url) {{
+					setName(name);
+				}});
+			}
 		}
 
 		for (Entry<String, Filter> filterBean : getOrderedBeansOfType(Filter.class)) {

spring-bootstrap/src/main/java/org/springframework/bootstrap/context/embedded/ServletRegistrationBean.java

@@ -22,6 +22,7 @@ import java.util.LinkedHashSet;
 import java.util.Set;
 
 import javax.servlet.Filter;
+import javax.servlet.MultipartConfigElement;
 import javax.servlet.Servlet;
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
@@ -55,6 +56,8 @@ public class ServletRegistrationBean extends RegistrationBean {
 	private int loadOnStartup = 1;
 
 	private Set<Filter> filters = new LinkedHashSet<Filter>();
+	
+	private MultipartConfigElement multipartConfigElement = null;
 
 	/**
 	 * Create a new {@link ServletRegistrationBean} instance.
@@ -72,6 +75,11 @@ public class ServletRegistrationBean extends RegistrationBean {
 		setServlet(servlet);
 		addUrlMappings(urlMappings);
 	}
+	
+	public ServletRegistrationBean(Servlet servlet, MultipartConfigElement multipartConfigElement, String... urlMappings) {
+		this(servlet, urlMappings);
+		this.multipartConfigElement = multipartConfigElement;
+	}
 
 	/**
 	 * Sets the servlet to be registered.
@@ -181,5 +189,8 @@ public class ServletRegistrationBean extends RegistrationBean {
 		}
 		registration.addMapping(urlMapping);
 		registration.setLoadOnStartup(this.loadOnStartup);
+		if (multipartConfigElement != null) {
+			registration.setMultipartConfig(multipartConfigElement);
+		}
 	}
 }

spring-bootstrap/src/test/java/org/springframework/bootstrap/autoconfigure/web/MultipartAutoConfigurationTests.java

@@ -0,0 +1,234 @@
+/*
+ * Copyright 2012-2013 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.bootstrap.autoconfigure.web;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.fail;
+
+import javax.servlet.MultipartConfigElement;
+
+import org.junit.Test;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.bootstrap.context.embedded.AnnotationConfigEmbeddedWebApplicationContext;
+import org.springframework.bootstrap.context.embedded.jetty.JettyEmbeddedServletContainerFactory;
+import org.springframework.bootstrap.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.multipart.MultipartResolver;
+import org.springframework.web.multipart.support.StandardServletMultipartResolver;
+import org.springframework.web.servlet.DispatcherServlet;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+
+/**
+ * A series of embedded unit tests, based on an empty configuration, no multipart
+ * configuration, and a multipart configuration, with both Jetty and Tomcat.
+ * 
+ * @author Greg Turnquist
+ */
+public class MultipartAutoConfigurationTests {
+	
+	private AnnotationConfigEmbeddedWebApplicationContext context;
+	
+	@Test
+	public void containerWithNothing() {
+		this.context = new AnnotationConfigEmbeddedWebApplicationContext(
+				ContainerWithNothing.class,
+				EmbeddedServletContainerAutoConfiguration.class,
+				MultipartAutoConfiguration.class);
+		try {
+			DispatcherServlet servlet = this.context.getBean(DispatcherServlet.class);
+			assertNull(servlet.getMultipartResolver());
+			try {
+				this.context.getBean(StandardServletMultipartResolver.class);
+				fail("Expected to receive a " + NoSuchBeanDefinitionException.class);
+			} catch (NoSuchBeanDefinitionException e) {
+			}
+			try {
+				this.context.getBean(MultipartResolver.class);
+				fail("Expected to receive a " + NoSuchBeanDefinitionException.class);
+			} catch (NoSuchBeanDefinitionException e) {
+			}
+		} finally {
+			this.context.close();
+		}
+	}
+	
+	@Configuration
+	public static class ContainerWithNothing {
+	}
+
+	@Test
+	public void containerWithNoMultipartJettyConfiguration() {
+		this.context = new AnnotationConfigEmbeddedWebApplicationContext(
+				ContainerWithNoMultipartJetty.class,
+				EmbeddedServletContainerAutoConfiguration.class,
+				MultipartAutoConfiguration.class);
+		try {
+			DispatcherServlet servlet = this.context.getBean(DispatcherServlet.class);
+			assertNull(servlet.getMultipartResolver());
+			try {
+				this.context.getBean(StandardServletMultipartResolver.class);
+				fail("Expected to receive a " + NoSuchBeanDefinitionException.class);
+			} catch (NoSuchBeanDefinitionException e) {
+			}
+			try {
+				this.context.getBean(MultipartResolver.class);
+				fail("Expected to receive a " + NoSuchBeanDefinitionException.class);
+			} catch (NoSuchBeanDefinitionException e) {
+			}
+			verifyServletWorks();
+		} finally {
+			this.context.close();
+		}
+	}
+
+	@Configuration
+	public static class ContainerWithNoMultipartJetty {
+		@Bean
+		JettyEmbeddedServletContainerFactory containerFactory() {
+			return new JettyEmbeddedServletContainerFactory();
+		}
+		@Bean
+		WebController controller() {
+			return new WebController();
+		}
+	}	
+
+	@Test
+	public void containerWithNoMultipartTomcatConfiguration() {
+		this.context = new AnnotationConfigEmbeddedWebApplicationContext(
+				ContainerWithNoMultipartTomcat.class,
+				EmbeddedServletContainerAutoConfiguration.class,
+				MultipartAutoConfiguration.class);
+		try {
+			DispatcherServlet servlet = this.context.getBean(DispatcherServlet.class);
+			assertNull(servlet.getMultipartResolver());
+			try {
+				this.context.getBean(StandardServletMultipartResolver.class);
+				fail("Expected to receive a " + NoSuchBeanDefinitionException.class);
+			} catch (NoSuchBeanDefinitionException e) {
+			}
+			try {
+				this.context.getBean(MultipartResolver.class);
+				fail("Expected to receive a " + NoSuchBeanDefinitionException.class);
+			} catch (NoSuchBeanDefinitionException e) {
+			}
+			verifyServletWorks();
+		} finally {
+			this.context.close();
+		}
+	}
+
+	@Configuration
+	public static class ContainerWithNoMultipartTomcat {
+		@Bean
+		TomcatEmbeddedServletContainerFactory containerFactory() {
+			return new TomcatEmbeddedServletContainerFactory();
+		}
+		@Bean
+		WebController controller() {
+			return new WebController();
+		}
+	}	
+
+	@Test
+	public void containerWithAutomatedMultipartJettyConfiguration() {
+		this.context = new AnnotationConfigEmbeddedWebApplicationContext(
+				ContainerWithEverythingJetty.class,
+				EmbeddedServletContainerAutoConfiguration.class,
+				MultipartAutoConfiguration.class);
+		try {
+			this.context.getBean(MultipartConfigElement.class);
+			assertSame(
+					this.context.getBean(DispatcherServlet.class).getMultipartResolver(), 
+					this.context.getBean(StandardServletMultipartResolver.class));
+			verifyServletWorks();
+		} finally {
+			this.context.close();
+		}
+	}
+
+	@Configuration
+	public static class ContainerWithEverythingJetty {
+		@Bean
+		MultipartConfigElement multipartConfigElement() {
+			return new MultipartConfigElement("");
+		}
+		@Bean
+		JettyEmbeddedServletContainerFactory containerFactory() {
+			return new JettyEmbeddedServletContainerFactory();
+		}
+		@Bean
+		WebController webController() {
+			return new WebController();
+		}
+	}
+
+	@Test
+	public void containerWithAutomatedMultipartTomcatConfiguration() {
+		this.context = new AnnotationConfigEmbeddedWebApplicationContext(
+				ContainerWithEverythingTomcat.class,
+				EmbeddedServletContainerAutoConfiguration.class,
+				MultipartAutoConfiguration.class);
+		try {
+			this.context.getBean(MultipartConfigElement.class);
+			assertSame(
+					this.context.getBean(DispatcherServlet.class).getMultipartResolver(), 
+					this.context.getBean(StandardServletMultipartResolver.class));
+			verifyServletWorks();
+		} finally {
+			this.context.close();
+		}
+	}
+
+	@Configuration
+	@EnableWebMvc
+	public static class ContainerWithEverythingTomcat {
+		@Bean
+		MultipartConfigElement multipartConfigElement() {
+			return new MultipartConfigElement("");
+		}
+		@Bean
+		TomcatEmbeddedServletContainerFactory containerFactory() {
+			return new TomcatEmbeddedServletContainerFactory();
+		}
+		@Bean
+		WebController webController() {
+			return new WebController();
+		}
+	}
+
+	@Controller
+	public static class WebController {
+		@RequestMapping("/")
+		public @ResponseBody String index() {
+			return "Hello";
+		}
+	}
+	
+	private void verifyServletWorks() {
+		RestTemplate restTemplate = new RestTemplate();
+		assertEquals(restTemplate.getForObject("http://localhost:8080/", String.class), "Hello");
+	}
+
+
+}