extend processor with after returning/throwing

SHL-40

src/main/java/org/springframework/shell/ExecutionProcessor.java

@@ -37,9 +37,19 @@ public interface ExecutionProcessor extends CommandMarker {
 	ParseResult beforeInvocation(ParseResult invocationContext);
 
 	/**
-	 * Method called after invoking the target command (described by {@link ParseResult}).
+	 * Method called after successfully invoking the target command (described by {@link ParseResult}).
 	 * 
 	 * @param invocationContext target command context
+	 * @param result the invocation result
 	 */
-	void afterInvocation(ParseResult invocationContext);
+	void afterReturningInvocation(ParseResult invocationContext, Object result);
+
+	/**
+	 * Method called after invoking the target command (described by {@link ParseResult}) had thrown an exception .
+	 * 
+	 * @param invocationContext target command context
+	 * @param thrown the thrown object
+	 */
+	void afterThrowingInvocation(ParseResult invocationContext, Throwable thrown);
+
 }

src/main/java/org/springframework/shell/SimpleExecutionStrategy.java

@@ -27,9 +27,18 @@ public class SimpleExecutionStrategy implements ExecutionStrategy {
 				ExecutionProcessor processor = ((ExecutionProcessor) target);
 				parseResult = processor.beforeInvocation(parseResult);
 				try {
-					return invoke(parseResult);
+					Object result = invoke(parseResult);
-				} finally {
+					processor.afterReturningInvocation(parseResult, result);
-					processor.afterInvocation(parseResult);
+					return result;
+				} catch (Throwable th) {
+					processor.afterThrowingInvocation(parseResult, th);
+					if (th instanceof Error) {
+						throw ((Error) th);
+					}
+					if (th instanceof RuntimeException) {
+						throw ((RuntimeException) th);
+					}
+					throw new RuntimeException(th);
 				}
 			}
 			else {

src/test/java/org/springframework/shell/SimpleExecutionStrategyTest.java

@@ -46,9 +46,13 @@ public class SimpleExecutionStrategyTest {
 			return (beforeReturn == null ? invocationContext : beforeReturn);
 		}
 
-		public void afterInvocation(ParseResult invocationContext) {
+		public void afterReturningInvocation(ParseResult invocationContext, Object result) {
 			after = invocationContext;
 		}
+
+		public void afterThrowingInvocation(ParseResult invocationContext, Throwable thrown) {
+			//
+		}
 	}
 
 	private SimpleExecutionStrategy execution = new SimpleExecutionStrategy();