From aa5ac4f7da25d635a2c51f9d79e667d3bad8d311 Mon Sep 17 00:00:00 2001
From: Robert von Burg <eitch@eitchnet.ch>
Date: Sat, 28 Dec 2013 13:00:26 +0100
Subject: [PATCH] [Minor] better exception handling if Service returns null
 service result

---
 .../java/li/strolch/service/AbstractService.java   | 14 +++++++++++---
 .../li/strolch/service/DefaultServiceHandler.java  |  5 +++++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/main/java/li/strolch/service/AbstractService.java b/src/main/java/li/strolch/service/AbstractService.java
index bef92cdf4..9682676ca 100644
--- a/src/main/java/li/strolch/service/AbstractService.java
+++ b/src/main/java/li/strolch/service/AbstractService.java
@@ -17,6 +17,7 @@ package li.strolch.service;
 
 import java.text.MessageFormat;
 
+import li.strolch.exception.StrolchException;
 import li.strolch.runtime.agent.api.ComponentContainer;
 
 import org.slf4j.Logger;
@@ -61,7 +62,14 @@ public abstract class AbstractService<T extends ServiceArgument, U extends Servi
 
 		try {
 
-			return internalDoService(argument);
+			U serviceResult = internalDoService(argument);
+			if (serviceResult == null) {
+				String msg = "Service {0} is not properly implemented as it returned a null result!"; //$NON-NLS-1$
+				msg = MessageFormat.format(msg, this.getClass().getName());
+				throw new StrolchException(msg);
+			}
+
+			return serviceResult;
 
 		} catch (Exception e) {
 
@@ -97,10 +105,10 @@ public abstract class AbstractService<T extends ServiceArgument, U extends Servi
 	 * Internal method to perform the {@link Service}. The implementor does not need to handle exceptions as this is
 	 * done in the {@link #doService(ServiceArgument)} which calls this method
 	 * 
-	 * @param argument
+	 * @param arg
 	 * @return
 	 */
-	protected abstract U internalDoService(T argument);
+	protected abstract U internalDoService(T arg);
 
 	/**
 	 * @see ch.eitchnet.privilege.model.Restrictable#getPrivilegeName()
diff --git a/src/main/java/li/strolch/service/DefaultServiceHandler.java b/src/main/java/li/strolch/service/DefaultServiceHandler.java
index 0ff6c98c3..3dbe77c5c 100644
--- a/src/main/java/li/strolch/service/DefaultServiceHandler.java
+++ b/src/main/java/li/strolch/service/DefaultServiceHandler.java
@@ -76,6 +76,11 @@ public class DefaultServiceHandler extends StrolchComponent implements ServiceHa
 			// then perform the service
 			service.setContainer(getContainer());
 			U serviceResult = service.doService(argument);
+			if (serviceResult == null) {
+				String msg = "Service {0} is not properly implemented as it returned a null result!"; //$NON-NLS-1$
+				msg = MessageFormat.format(msg, service);
+				throw new StrolchException(msg);
+			}
 
 			// log the result
 			long end = System.nanoTime();