SCT-35 Tasks Support TaskExecutionListener

resolves spring-cloud/spring-cloud-task#35

TaskExecutionListener now supports TaskExecution Params

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/listener/TaskExecutionListener.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.task.listener;
+
+import org.springframework.cloud.task.repository.TaskExecution;
+import org.springframework.cloud.task.repository.TaskRepository;
+
+/**
+ * The listener interface for receiving task execution events.
+ * @author Glenn Renfro
+ */
+public interface TaskExecutionListener {
+
+	/**
+	 * Invoked after the {@link TaskExecution} has been stored in the {@link TaskRepository}.
+	 * @param taskExecution instance containing the information about the current task.
+	 */
+	public void onTaskStartup(TaskExecution taskExecution);
+
+	/**
+	 * Invoked before the {@link TaskExecution} has been updated in the {@link TaskRepository}
+	 * upon task end.
+	 * @param taskExecution instance containing the information about the current task.
+	 */
+	public void onTaskEnd(TaskExecution taskExecution);
+
+	/**
+	 * Invoked if an uncaught exception occurs during a task execution.  This invocation
+	 * will occur before the {@link TaskExecution} has been updated in the {@link TaskRepository}
+	 * and before the onTaskEnd is called.
+	 * @param taskExecution instance containing the information about the current task.
+	 * @param throwable the uncaught exception that was thrown during task execution.
+	 */
+	public void onTaskFailed(TaskExecution taskExecution, Throwable throwable);
+
+}

spring-cloud-task-core/src/main/java/org/springframework/cloud/task/listener/TaskLifecycleListener.java

@@ -19,12 +19,14 @@ import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.ApplicationArguments;
 import org.springframework.boot.ExitCodeEvent;
 import org.springframework.boot.context.event.ApplicationFailedEvent;
@@ -57,6 +59,9 @@ import org.springframework.util.Assert;
  */
 public class TaskLifecycleListener implements ApplicationListener<ApplicationEvent>{
 
+	@Autowired(required = false)
+	Collection<TaskExecutionListener> taskExecutionListeners;
+
 	private final static Logger logger = LoggerFactory.getLogger(TaskLifecycleListener.class);
 
 	private final TaskRepository taskRepository;
@@ -142,6 +147,11 @@ public class TaskLifecycleListener implements ApplicationListener<ApplicationEve
 				this.taskExecution.setExitMessage(stackTraceToString(this.applicationFailedEvent.getException()));
 			}
 
+			if(this.taskExecution.getExitCode() != 0){
+				taskExecution.setExitMessage(invokeOnTaskError(taskExecution,
+						this.applicationFailedEvent.getException()).getExitMessage());
+			}
+			taskExecution.setExitMessage(invokeOnTaskEnd(taskExecution).getExitMessage());
 			taskRepository.update(taskExecution);
 		}
 		else {
@@ -169,5 +179,47 @@ public class TaskLifecycleListener implements ApplicationListener<ApplicationEve
 			logger.error("Multiple start events have been received.  The first one was " +
 					"recorded.");
 		}
+		taskExecution.setExitMessage(invokeOnTaskStartup(taskExecution).getExitMessage());
+	}
+
+	private TaskExecution invokeOnTaskStartup(TaskExecution taskExecution){
+		TaskExecution listenerTaskExecution = getTaskExecutionCopy(taskExecution);
+		if (taskExecutionListeners != null) {
+			for (TaskExecutionListener taskExecutionListener : taskExecutionListeners) {
+				taskExecutionListener.onTaskStartup(listenerTaskExecution);
+			}
+		}
+		return listenerTaskExecution;
+	}
+
+	private TaskExecution invokeOnTaskEnd(TaskExecution taskExecution){
+		TaskExecution listenerTaskExecution = getTaskExecutionCopy(taskExecution);
+		if (taskExecutionListeners != null) {
+			for (TaskExecutionListener taskExecutionListener : taskExecutionListeners) {
+				taskExecutionListener.onTaskEnd(listenerTaskExecution);
+			}
+		}
+		return listenerTaskExecution;
+	}
+
+	private TaskExecution invokeOnTaskError(TaskExecution taskExecution, Throwable throwable){
+		TaskExecution listenerTaskExecution = getTaskExecutionCopy(taskExecution);
+		if (taskExecutionListeners != null) {
+			for (TaskExecutionListener taskExecutionListener : taskExecutionListeners) {
+				taskExecutionListener.onTaskFailed(listenerTaskExecution, throwable);
+			}
+		}
+		return listenerTaskExecution;
+	}
+
+	private TaskExecution getTaskExecutionCopy(TaskExecution taskExecution){
+		Date startTime = new Date(taskExecution.getStartTime().getTime());
+		Date endTime = (taskExecution.getEndTime() == null) ?
+				null : new Date(taskExecution.getEndTime().getTime());
+
+		return new TaskExecution(taskExecution.getExecutionId(),
+				taskExecution.getExitCode(), taskExecution.getTaskName(), startTime,
+				endTime,taskExecution.getExitMessage(),
+				Collections.unmodifiableList(taskExecution.getParameters()));
 	}
 }