Update port file writer to support reactive servers

Closes gh-8531

spring-boot/src/main/java/org/springframework/boot/system/EmbeddedServerPortFileWriter.java

@@ -21,12 +21,14 @@ import java.io.File;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
-import org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext;
-import org.springframework.boot.web.servlet.context.ServletWebServerInitializedEvent;
+import org.springframework.boot.web.context.WebServerInitializedEvent;
+import org.springframework.boot.web.reactive.context.ReactiveWebApplicationContext;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationListener;
 import org.springframework.util.Assert;
 import org.springframework.util.FileCopyUtils;
 import org.springframework.util.StringUtils;
+import org.springframework.web.context.ConfigurableWebApplicationContext;
 
 /**
  * An {@link ApplicationListener} that saves embedded server port and management port into
@@ -40,7 +42,7 @@ import org.springframework.util.StringUtils;
  * @since 1.4.0
  */
 public class EmbeddedServerPortFileWriter
-		implements ApplicationListener<ServletWebServerInitializedEvent> {
+		implements ApplicationListener<WebServerInitializedEvent> {
 
 	private static final String DEFAULT_FILE_NAME = "application.port";
 
@@ -84,7 +86,7 @@ public class EmbeddedServerPortFileWriter
 	}
 
 	@Override
-	public void onApplicationEvent(ServletWebServerInitializedEvent event) {
+	public void onApplicationEvent(WebServerInitializedEvent event) {
 		File portFile = getPortFile(event.getApplicationContext());
 		try {
 			String port = String.valueOf(event.getWebServer().getPort());
@@ -100,12 +102,12 @@ public class EmbeddedServerPortFileWriter
 	/**
 	 * Return the actual port file that should be written for the given application
 	 * context. The default implementation builds a file from the source file and the
-	 * application context namespace.
+	 * application context namespace if available.
 	 * @param applicationContext the source application context
 	 * @return the file that should be written
 	 */
-	protected File getPortFile(ServletWebServerApplicationContext applicationContext) {
-		String contextName = applicationContext.getNamespace();
+	protected File getPortFile(ApplicationContext applicationContext) {
+		String contextName = getContextName(applicationContext);
 		if (StringUtils.isEmpty(contextName)) {
 			return this.file;
 		}
@@ -124,6 +126,17 @@ public class EmbeddedServerPortFileWriter
 		return new File(this.file.getParentFile(), name);
 	}
 
+	private String getContextName(ApplicationContext applicationContext) {
+		if (applicationContext instanceof ConfigurableWebApplicationContext) {
+			return ((ConfigurableWebApplicationContext) applicationContext)
+					.getNamespace();
+		}
+		if (applicationContext instanceof ReactiveWebApplicationContext) {
+			return ((ReactiveWebApplicationContext) applicationContext).getNamespace();
+		}
+		return null;
+	}
+
 	private boolean isUpperCase(String name) {
 		for (int i = 0; i < name.length(); i++) {
 			if (Character.isLetter(name.charAt(i))

spring-boot/src/main/java/org/springframework/boot/web/reactive/context/GenericReactiveWebApplicationContext.java

@@ -28,6 +28,8 @@ import org.springframework.context.annotation.AnnotationConfigApplicationContext
 public class GenericReactiveWebApplicationContext extends
 		AnnotationConfigApplicationContext implements ReactiveWebApplicationContext {
 
+	private String namespace;
+
 	public GenericReactiveWebApplicationContext() {
 		super();
 	}
@@ -36,4 +38,14 @@ public class GenericReactiveWebApplicationContext extends
 		super(annotatedClasses);
 	}
 
+	@Override
+	public void setNamespace(String namespace) {
+		this.namespace = namespace;
+	}
+
+	@Override
+	public String getNamespace() {
+		return this.namespace;
+	}
+
 }

spring-boot/src/main/java/org/springframework/boot/web/reactive/context/ReactiveWebApplicationContext.java

@@ -26,4 +26,16 @@ import org.springframework.context.ApplicationContext;
  */
 public interface ReactiveWebApplicationContext extends ApplicationContext {
 
+	/**
+	 * Set the namespace for this reactive web application context.
+	 * @param namespace the namespace for the context
+	 */
+	void setNamespace(String namespace);
+
+	/**
+	 * Return the namespace for this reactive web application context, if any.
+	 * @return the namespace or {@code null}
+	 */
+	String getNamespace();
+
 }

spring-boot/src/test/java/org/springframework/boot/system/EmbeddedServerPortFileWriterTests.java

@@ -20,13 +20,20 @@ import java.io.File;
 import java.io.FileReader;
 import java.util.HashSet;
 import java.util.Set;
+import java.util.function.BiFunction;
 
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
 
+import org.springframework.boot.web.context.WebServerInitializedEvent;
+import org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext;
+import org.springframework.boot.web.reactive.context.ReactiveWebServerInitializedEvent;
 import org.springframework.boot.web.server.WebServer;
 import org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext;
 import org.springframework.boot.web.servlet.context.ServletWebServerInitializedEvent;
@@ -44,10 +51,44 @@ import static org.mockito.Mockito.mock;
  * @author Phillip Webb
  * @author Andy Wilkinson
  */
+@RunWith(Parameterized.class)
 public class EmbeddedServerPortFileWriterTests {
 
 	@Rule
-	public TemporaryFolder temporaryFolder = new TemporaryFolder();
+	public final TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+	@Parameters(name = "{0}")
+	public static Object[] parameters() {
+		BiFunction<String, Integer, ? extends WebServerInitializedEvent> servletEvent = (
+				String name, Integer port) -> {
+			ServletWebServerApplicationContext applicationContext = mock(
+					ServletWebServerApplicationContext.class);
+			given(applicationContext.getNamespace()).willReturn(name);
+			WebServer source = mock(WebServer.class);
+			given(source.getPort()).willReturn(port);
+			ServletWebServerInitializedEvent event = new ServletWebServerInitializedEvent(
+					applicationContext, source);
+			return event;
+		};
+		BiFunction<String, Integer, ? extends WebServerInitializedEvent> reactiveEvent = (
+				String name, Integer port) -> {
+			ReactiveWebServerApplicationContext applicationContext = mock(
+					ReactiveWebServerApplicationContext.class);
+			given(applicationContext.getNamespace()).willReturn(name);
+			WebServer source = mock(WebServer.class);
+			given(source.getPort()).willReturn(port);
+			return new ReactiveWebServerInitializedEvent(source, applicationContext);
+		};
+		return new Object[] { new Object[] { "Servlet", servletEvent },
+				new Object[] { "Reactive", reactiveEvent } };
+	}
+
+	private final BiFunction<String, Integer, ? extends WebServerInitializedEvent> eventFactory;
+
+	public EmbeddedServerPortFileWriterTests(String name,
+			BiFunction<String, Integer, ? extends WebServerInitializedEvent> eventFactory) {
+		this.eventFactory = eventFactory;
+	}
 
 	@Before
 	@After
@@ -117,15 +158,8 @@ public class EmbeddedServerPortFileWriterTests {
 		assertThat(collectFileNames(file.getParentFile())).contains(managementFile);
 	}
 
-	private ServletWebServerInitializedEvent mockEvent(String name, int port) {
-		ServletWebServerApplicationContext applicationContext = mock(
-				ServletWebServerApplicationContext.class);
-		WebServer source = mock(WebServer.class);
-		given(applicationContext.getNamespace()).willReturn(name);
-		given(source.getPort()).willReturn(port);
-		ServletWebServerInitializedEvent event = new ServletWebServerInitializedEvent(
-				applicationContext, source);
-		return event;
+	private WebServerInitializedEvent mockEvent(String name, int port) {
+		return this.eventFactory.apply(name, port);
 	}
 
 	private Set<String> collectFileNames(File directory) {