Expose additional admin features

Improve SpringApplicationAdminMXBean to expose additional information:

* Whether the application uses an embedded container
* The properties exposed by the `Environment`

This allows to know if the application is web-based and the HTTP port
on which it is running.

Closes gh-3067

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/admin/SpringApplicationAdminJmxAutoConfigurationTests.java

@@ -30,10 +30,18 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration;
+import org.springframework.boot.autoconfigure.web.DispatcherServletAutoConfiguration;
+import org.springframework.boot.autoconfigure.web.EmbeddedServletContainerAutoConfiguration;
+import org.springframework.boot.autoconfigure.web.ServerPropertiesAutoConfiguration;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.context.embedded.EmbeddedWebApplicationContext;
 import org.springframework.boot.test.EnvironmentTestUtils;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 /**
@@ -52,7 +60,7 @@ public class SpringApplicationAdminJmxAutoConfigurationTests {
 	@Rule
 	public final ExpectedException thrown = ExpectedException.none();
 
-	private AnnotationConfigApplicationContext context;
+	private ConfigurableApplicationContext context;
 
 	private MBeanServer mBeanServer;
 
@@ -104,6 +112,22 @@ public class SpringApplicationAdminJmxAutoConfigurationTests {
 		}
 	}
 
+	@SuppressWarnings("unchecked")
+	@Test
+	public void registerWithSimpleWebApp() throws Exception {
+		this.context = new SpringApplicationBuilder()
+				.sources(
+						EmbeddedServletContainerAutoConfiguration.class,
+						ServerPropertiesAutoConfiguration.class, DispatcherServletAutoConfiguration.class,
+						JmxAutoConfiguration.class, SpringApplicationAdminJmxAutoConfiguration.class)
+				.run("--" + ENABLE_ADMIN_PROP, "--server.port=0");
+		assertTrue(this.context instanceof EmbeddedWebApplicationContext);
+		assertEquals(true, this.mBeanServer.getAttribute(createDefaultObjectName(), "EmbeddedWebApplication"));
+		int expected = ((EmbeddedWebApplicationContext) this.context).getEmbeddedServletContainer().getPort();
+		String actual = getProperty(createDefaultObjectName(), "local.server.port");
+		assertEquals(String.valueOf(expected), actual);
+	}
+
 	private ObjectName createDefaultObjectName() {
 		return createObjectName(DEFAULT_JMX_NAME);
 	}
@@ -117,6 +141,11 @@ public class SpringApplicationAdminJmxAutoConfigurationTests {
 		}
 	}
 
+	private String getProperty(ObjectName objectName, String key) throws Exception {
+		return (String) this.mBeanServer.invoke(objectName, "getProperty",
+				new Object[]{key}, new String[]{String.class.getName()});
+	}
+
 	private void load(String... environment) {
 		AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext();
 		EnvironmentTestUtils.addEnvironment(applicationContext, environment);

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -228,6 +228,9 @@ It is possible to enable admin-related features for the application by specifyin
 on the platform `MBeanServer`. You could use this feature to administer your Spring Boot
 application remotely. This could also be useful for any service wrapper implementation.
 
+TIP: If you want to know on which HTTP port the application is running, get the property
+with key `local.server.port`.
+
 NOTE: Take care when enabling this feature as the MBean exposes a method to shutdown the
 application.
 

spring-boot/src/main/java/org/springframework/boot/admin/SpringApplicationAdminMXBean.java

@@ -32,6 +32,23 @@ public interface SpringApplicationAdminMXBean {
 	 */
 	boolean isReady();
 
+	/**
+	 * Specify if the application runs in an embedded web container. Can return
+	 * {@code null} if that information is not yet available. It is preferable to
+	 * wait for the application to be {@link #isReady() ready}.
+	 * @return {@code true} if the application runs in an embedded web container
+	 * @see #isReady()
+	 */
+	boolean isEmbeddedWebApplication();
+
+	/**
+	 * Return the value of the specified key from the application
+	 * {@link org.springframework.core.env.Environment Environment}.
+	 * @param key the property key
+	 * @return the property value or {@code null} if it does not exist
+	 */
+	String getProperty(String key);
+
 	/**
 	 * Shutdown the application.
 	 * @see org.springframework.context.ConfigurableApplicationContext#close()

spring-boot/src/main/java/org/springframework/boot/admin/SpringApplicationAdminMXBeanRegistrar.java

@@ -27,11 +27,15 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.DisposableBean;
 import org.springframework.beans.factory.InitializingBean;
+import org.springframework.boot.context.embedded.EmbeddedWebApplicationContext;
 import org.springframework.boot.context.event.ApplicationReadyEvent;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.EnvironmentAware;
+import org.springframework.core.env.Environment;
+import org.springframework.core.env.StandardEnvironment;
 import org.springframework.util.Assert;
 
 /**
@@ -42,12 +46,14 @@ import org.springframework.util.Assert;
  * @since 1.3.0
  */
 public class SpringApplicationAdminMXBeanRegistrar implements ApplicationContextAware,
-		InitializingBean, DisposableBean, ApplicationListener<ApplicationReadyEvent> {
+		EnvironmentAware, InitializingBean, DisposableBean, ApplicationListener<ApplicationReadyEvent> {
 
 	private static final Log logger = LogFactory.getLog(SpringApplicationAdmin.class);
 
 	private ConfigurableApplicationContext applicationContext;
 
+	private Environment environment = new StandardEnvironment();
+
 	private final ObjectName objectName;
 
 	private boolean ready = false;
@@ -65,6 +71,11 @@ public class SpringApplicationAdminMXBeanRegistrar implements ApplicationContext
 		this.applicationContext = (ConfigurableApplicationContext) applicationContext;
 	}
 
+	@Override
+	public void setEnvironment(Environment environment) {
+		this.environment = environment;
+	}
+
 	@Override
 	public void onApplicationEvent(ApplicationReadyEvent event) {
 		this.ready = true;
@@ -92,6 +103,17 @@ public class SpringApplicationAdminMXBeanRegistrar implements ApplicationContext
 			return SpringApplicationAdminMXBeanRegistrar.this.ready;
 		}
 
+		@Override
+		public boolean isEmbeddedWebApplication() {
+			return (applicationContext != null
+					&& applicationContext instanceof EmbeddedWebApplicationContext);
+		}
+
+		@Override
+		public String getProperty(String key) {
+			return environment.getProperty(key);
+		}
+
 		@Override
 		public void shutdown() {
 			logger.info("Application shutdown requested.");

spring-boot/src/main/java/org/springframework/boot/admin/SpringApplicationAdminMXBeanRegistrarTests.java

@@ -29,15 +29,15 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import org.springframework.boot.SpringApplication;
-import org.springframework.boot.admin.SpringApplicationAdminMXBeanRegistrar;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.event.ContextRefreshedEvent;
 
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.junit.Assert.assertThat;
 
 /**
  * Tests for {@link SpringApplicationAdminMXBeanRegistrar}.
@@ -76,8 +76,7 @@ public class SpringApplicationAdminMXBeanRegistrarTests {
 			@Override
 			public void onApplicationEvent(ContextRefreshedEvent event) {
 				try {
-					assertFalse("Application should not be ready yet",
-							isCurrentApplicationReady(objectName));
+					assertThat(isApplicationReady(objectName), is(false));
 				}
 				catch (Exception ex) {
 					throw new IllegalStateException(
@@ -86,8 +85,19 @@ public class SpringApplicationAdminMXBeanRegistrarTests {
 			}
 		});
 		this.context = application.run();
-		assertTrue("application should be ready now",
-				isCurrentApplicationReady(objectName));
+		assertThat(isApplicationReady(objectName), is(true));
+	}
+
+	@Test
+	public void environmentIsExposed() {
+		final ObjectName objectName = createObjectName(OBJECT_NAME);
+		SpringApplication application = new SpringApplication(Config.class);
+		application.setWebEnvironment(false);
+		this.context = application.run("--foo.bar=blam");
+		assertThat(isApplicationReady(objectName), is(true));
+		assertThat(isApplicationEmbeddedWebApplication(objectName), is(false));
+		assertThat(getProperty(objectName, "foo.bar"), is("blam"));
+		assertThat(getProperty(objectName, "does.not.exist.test"), is(nullValue()));
 	}
 
 	@Test
@@ -96,16 +106,36 @@ public class SpringApplicationAdminMXBeanRegistrarTests {
 		SpringApplication application = new SpringApplication(Config.class);
 		application.setWebEnvironment(false);
 		this.context = application.run();
-		assertTrue("application should be running", this.context.isRunning());
+		assertThat(this.context.isRunning(), is(true));
 		invokeShutdown(objectName);
-		assertFalse("application should not be running", this.context.isRunning());
+		assertThat(this.context.isRunning(), is(false));
 		this.thrown.expect(InstanceNotFoundException.class); // JMX cleanup
 		this.mBeanServer.getObjectInstance(objectName);
 	}
 
-	private Boolean isCurrentApplicationReady(ObjectName objectName) {
+	private Boolean isApplicationReady(ObjectName objectName) {
+		return getAttribute(objectName, Boolean.class, "Ready");
+	}
+
+	private Boolean isApplicationEmbeddedWebApplication(ObjectName objectName) {
+		return getAttribute(objectName, Boolean.class, "EmbeddedWebApplication");
+	}
+
+	private String getProperty(ObjectName objectName, String key) {
+		try {
+			return (String) this.mBeanServer.invoke(objectName, "getProperty",
+					new Object[] {key}, new String[] {String.class.getName()});
+		}
+		catch (Exception ex) {
+			throw new IllegalStateException(ex.getMessage(), ex);
+		}
+	}
+
+	private <T> T getAttribute(ObjectName objectName, Class<T> type, String attribute) {
 		try {
-			return (Boolean) this.mBeanServer.getAttribute(objectName, "Ready");
+			Object value = this.mBeanServer.getAttribute(objectName, attribute);
+			assertThat((value == null || type.isInstance(value)), is(true));
+			return type.cast(value);
 		}
 		catch (Exception ex) {
 			throw new IllegalStateException(ex.getMessage(), ex);