Add @IntegrationTest annotation for test classes

Allowing use of embededded container in @SpringApplicationConfiguration
tests, e.g.

```
@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = Config.class)
@WebAppConfiguration
@IntegrationTest
public class SpringApplicationIntegrationTestTests {

	@Test
	public void nestedConfigClasses() {
		String body = new RestTemplate().getForObject("http://localhost:8080/",
				String.class);
		assertEquals("Hello World", body);
	}

	@Configuration
	@EnableWebMvc
	@RestController
	protected static class Config {

		@Bean
		public DispatcherServlet dispatcherServlet() {
			return new DispatcherServlet();
		}

		@Bean
		public EmbeddedServletContainerFactory embeddedServletContainer() {
			return new TomcatEmbeddedServletContainerFactory();
		}

		@RequestMapping("/")
		public String home() {
			return "Hello World";
		}

	}

}
```

Fixes gh-473

spring-boot/src/main/java/org/springframework/boot/test/IntegrationTest.java

@@ -0,0 +1,48 @@
+/*
+ * 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.boot.test;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.test.context.TestExecutionListeners;
+import org.springframework.test.context.support.DependencyInjectionTestExecutionListener;
+import org.springframework.test.context.support.DirtiesContextTestExecutionListener;
+import org.springframework.test.context.transaction.TransactionalTestExecutionListener;
+
+/**
+ * Test class annotation signifying that the tests are integration tests (and therefore
+ * require an application to startup "fully leaded" and listening on their normal ports).
+ * 
+ * @author Dave Syer
+ */
+@Documented
+@Inherited
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+// Leave out the ServletTestExecutionListener because it only deals with Mock* servlet
+// stuff. A real embedded application will not need the mocks.
+@TestExecutionListeners(listeners = { DependencyInjectionTestExecutionListener.class,
+		DirtiesContextTestExecutionListener.class,
+		TransactionalTestExecutionListener.class })
+public @interface IntegrationTest {
+
+}

spring-boot/src/main/java/org/springframework/boot/test/SpringApplicationContextLoader.java

@@ -30,6 +30,7 @@ import org.springframework.boot.context.web.ServletContextApplicationContextInit
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextInitializer;
 import org.springframework.core.SpringVersion;
+import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.mock.web.MockServletContext;
 import org.springframework.test.context.ContextConfigurationAttributes;
 import org.springframework.test.context.ContextLoader;
@@ -127,8 +128,11 @@ public class SpringApplicationContextLoader extends AbstractContextLoader {
 
 	private Map<String, Object> getArgs(MergedContextConfiguration mergedConfig) {
 		Map<String, Object> args = new LinkedHashMap<String, Object>();
-		// Not running an embedded server, just setting up web context
-		args.put("server.port", "-1");
+		if (AnnotationUtils.findAnnotation(mergedConfig.getTestClass(),
+				IntegrationTest.class) == null) {
+			// Not running an embedded server, just setting up web context
+			args.put("server.port", "-1");
+		}
 		// JMX bean names will clash if the same bean is used in multiple contexts
 		args.put("spring.jmx.enabled", "false");
 		return args;
@@ -161,11 +165,15 @@ public class SpringApplicationContextLoader extends AbstractContextLoader {
 				SpringApplication application,
 				List<ApplicationContextInitializer<?>> initializers) {
 			WebMergedContextConfiguration webConfig = (WebMergedContextConfiguration) mergedConfig;
-			MockServletContext servletContext = new MockServletContext(
-					webConfig.getResourceBasePath());
-			initializers.add(0, new ServletContextApplicationContextInitializer(
-					servletContext));
-			application.setApplicationContextClass(GenericWebApplicationContext.class);
+			if (AnnotationUtils.findAnnotation(webConfig.getTestClass(),
+					IntegrationTest.class) == null) {
+				MockServletContext servletContext = new MockServletContext(
+						webConfig.getResourceBasePath());
+				initializers.add(0, new ServletContextApplicationContextInitializer(
+						servletContext));
+				application
+						.setApplicationContextClass(GenericWebApplicationContext.class);
+			}
 		}
 	}
 

spring-boot/src/test/java/org/springframework/boot/test/SpringApplicationIntegrationTestTests.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2012-2014 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.boot.test;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.context.embedded.EmbeddedServletContainerFactory;
+import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
+import org.springframework.boot.test.SpringApplicationIntegrationTestTests.Config;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.servlet.DispatcherServlet;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Tests for {@link IntegrationTest}
+ * 
+ * @author Dave Syer
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringApplicationConfiguration(classes = Config.class)
+@WebAppConfiguration
+@IntegrationTest
+public class SpringApplicationIntegrationTestTests {
+
+	@Test
+	public void nestedConfigClasses() {
+		String body = new RestTemplate().getForObject("http://localhost:8080/",
+				String.class);
+		assertEquals("Hello World", body);
+	}
+
+	@Configuration
+	@EnableWebMvc
+	@RestController
+	protected static class Config {
+
+		@Bean
+		public DispatcherServlet dispatcherServlet() {
+			return new DispatcherServlet();
+		}
+
+		@Bean
+		public EmbeddedServletContainerFactory embeddedServletContainer() {
+			return new TomcatEmbeddedServletContainerFactory();
+		}
+
+		@RequestMapping("/")
+		public String home() {
+			return "Hello World";
+		}
+
+	}
+
+}