Catch application exception in tomcat starter thread and rethrow

Fixes gh-1088

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

@@ -16,12 +16,12 @@
 
 package org.springframework.boot.context.embedded.tomcat;
 
-import javax.servlet.ServletException;
-
 import org.apache.catalina.Lifecycle;
 import org.apache.catalina.LifecycleEvent;
 import org.apache.catalina.LifecycleListener;
 import org.apache.catalina.core.StandardContext;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.springframework.boot.context.embedded.ServletContextInitializer;
 import org.springframework.util.Assert;
 
@@ -29,10 +29,15 @@ import org.springframework.util.Assert;
  * Tomcat {@link LifecycleListener} that calls {@link ServletContextInitializer}s.
  * 
  * @author Phillip Webb
+ * @author Dave Syer
  */
 public class ServletContextInitializerLifecycleListener implements LifecycleListener {
 
+	private static Log logger = LogFactory
+			.getLog(ServletContextInitializerLifecycleListener.class);
+
 	private final ServletContextInitializer[] initializers;
+	private Exception startUpException;
 
 	/**
 	 * Create a new {@link ServletContextInitializerLifecycleListener} instance with the
@@ -44,6 +49,10 @@ public class ServletContextInitializerLifecycleListener implements LifecycleList
 		this.initializers = initializers;
 	}
 
+	public Exception getStartUpException() {
+		return this.startUpException;
+	}
+
 	@Override
 	public void lifecycleEvent(LifecycleEvent event) {
 		if (Lifecycle.CONFIGURE_START_EVENT.equals(event.getType())) {
@@ -53,8 +62,13 @@ public class ServletContextInitializerLifecycleListener implements LifecycleList
 				try {
 					initializer.onStartup(standardContext.getServletContext());
 				}
-				catch (ServletException ex) {
-					throw new IllegalStateException(ex);
+				catch (Exception ex) {
+					this.startUpException = ex;
+					// Prevent Tomcat from logging and re-throwing when we know we can
+					// deal with it in the main thread, but log for information here.
+					logger.error("Error starting Tomcat context: "
+							+ ex.getClass().getName());
+					break;
 				}
 			}
 		}

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

@@ -28,6 +28,8 @@ import org.springframework.util.ClassUtils;
  */
 class TomcatEmbeddedContext extends StandardContext {
 
+	private ServletContextInitializerLifecycleListener starter;
+
 	@Override
 	public void loadOnStartup(Container[] children) {
 	}
@@ -49,4 +51,12 @@ class TomcatEmbeddedContext extends StandardContext {
 		}
 	}
 
+	public void setStarter(ServletContextInitializerLifecycleListener starter) {
+		this.starter = starter;
+	}
+
+	public ServletContextInitializerLifecycleListener getStarter() {
+		return this.starter;
+	}
+
 }

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

@@ -77,6 +77,16 @@ public class TomcatEmbeddedServletContainer implements EmbeddedServletContainer
 				engine.setName(engine.getName() + "-" + instanceId);
 			}
 			this.tomcat.start();
+			Container[] children = this.tomcat.getHost().findChildren();
+			for (Container container : children) {
+				if (container instanceof TomcatEmbeddedContext) {
+					Exception exception = ((TomcatEmbeddedContext) container)
+							.getStarter().getStartUpException();
+					if (exception != null) {
+						throw exception;
+					}
+				}
+			}
 			try {
 				// Allow the server to start so the ServletContext is available, but stop
 				// the connector to prevent requests from being handled before the Spring

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

@@ -242,8 +242,13 @@ public class TomcatEmbeddedServletContainerFactory extends
 	 */
 	protected void configureContext(Context context,
 			ServletContextInitializer[] initializers) {
-		context.addLifecycleListener(new ServletContextInitializerLifecycleListener(
-				initializers));
+		ServletContextInitializerLifecycleListener starter = new ServletContextInitializerLifecycleListener(
+				initializers);
+		if (context instanceof TomcatEmbeddedContext) {
+			// Should be true
+			((TomcatEmbeddedContext) context).setStarter(starter);
+		}
+		context.addLifecycleListener(starter);
 		for (LifecycleListener lifecycleListener : this.contextLifecycleListeners) {
 			context.addLifecycleListener(lifecycleListener);
 		}