Set the default session timeout to 30 mins

Update AbstractConfigurableEmbeddedServletContainer to set the default
session timeout to 30 minutes. Also correct Javadoc to specify that
the default is '30 minutes'.

Fixes gh-2084

Author: philwebb

spring-boot/src/main/java/org/springframework/boot/context/embedded/AbstractConfigurableEmbeddedServletContainer.java

@@ -37,6 +37,9 @@
 public abstract class AbstractConfigurableEmbeddedServletContainer implements
 		ConfigurableEmbeddedServletContainer {
 
+	private static final int DEFAULT_SESSION_TIMEOUT = (int) TimeUnit.SECONDS
+			.toMinutes(30);
+
 	private String contextPath = "";
 
 	private boolean registerDefaultServlet = true;
@@ -57,7 +60,7 @@ public abstract class AbstractConfigurableEmbeddedServletContainer implements
 
 	private InetAddress address;
 
-	private int sessionTimeout;
+	private int sessionTimeout = DEFAULT_SESSION_TIMEOUT;
 
 	private Ssl ssl;
 

spring-boot/src/main/java/org/springframework/boot/context/embedded/ConfigurableEmbeddedServletContainer.java

@@ -49,8 +49,8 @@ public interface ConfigurableEmbeddedServletContainer {
 	void setPort(int port);
 
 	/**
-	 * The session timeout in seconds (default 30). If 0 or negative then sessions never
-	 * expire.
+	 * The session timeout in seconds (default 30 minutes). If 0 or negative then sessions
+	 * never expire.
 	 * @param sessionTimeout the session timeout
 	 */
 	void setSessionTimeout(int sessionTimeout);

spring-boot/src/main/java/org/springframework/boot/context/embedded/jetty/JettyEmbeddedServletContainerFactory.java

@@ -28,6 +28,7 @@
 import org.eclipse.jetty.http.MimeTypes;
 import org.eclipse.jetty.server.Connector;
 import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.SessionManager;
 import org.eclipse.jetty.server.handler.ErrorHandler;
 import org.eclipse.jetty.server.ssl.SslSocketConnector;
 import org.eclipse.jetty.servlet.ErrorPageErrorHandler;
@@ -227,13 +228,13 @@ protected final void configureWebAppContext(WebAppContext context,
 						.getClassLoader())) {
 			addJspServlet(context);
 		}
-
 		ServletContextInitializer[] initializersToUse = mergeInitializers(initializers);
 		Configuration[] configurations = getWebAppContextConfigurations(context,
 				initializersToUse);
 		context.setConfigurations(configurations);
-		context.getSessionHandler().getSessionManager()
-				.setMaxInactiveInterval(getSessionTimeout());
+		int sessionTimeout = (getSessionTimeout() > 0 ? getSessionTimeout() : -1);
+		SessionManager sessionManager = context.getSessionHandler().getSessionManager();
+		sessionManager.setMaxInactiveInterval(sessionTimeout);
 		postProcessWebAppContext(context);
 	}
 

spring-boot/src/main/java/org/springframework/boot/context/embedded/tomcat/TomcatEmbeddedServletContainerFactory.java

@@ -344,12 +344,12 @@ protected void configureContext(Context context,
 		for (MimeMappings.Mapping mapping : getMimeMappings()) {
 			context.addMimeMapping(mapping.getExtension(), mapping.getMimeType());
 		}
-		long timeout = getSessionTimeout();
-		if (timeout > 0) {
+		long sessionTimeout = getSessionTimeout();
+		if (sessionTimeout > 0) {
 			// Tomcat timeouts are in minutes
-			timeout = Math.max(TimeUnit.SECONDS.toMinutes(timeout), 1L);
+			sessionTimeout = Math.max(TimeUnit.SECONDS.toMinutes(sessionTimeout), 1L);
 		}
-		context.setSessionTimeout((int) timeout);
+		context.setSessionTimeout((int) sessionTimeout);
 		for (TomcatContextCustomizer customizer : this.tomcatContextCustomizers) {
 			customizer.customize(context);
 		}