// Copyright 2004, 2005 The Apache Software Foundation
//
// 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 com.panorama.startup.impl;
import java.util.Iterator;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.hivemind.ErrorLog;
import org.apache.hivemind.Messages;
import org.apache.hivemind.order.Orderer;
/**
* A service that executes a series of {@link com.panorama.startup.impl.Task}s. Tasks have an
* ordering based on pre- and post-requisites.
*
* @author Howard Lewis Ship
*/
public class TaskExecutor implements Runnable
{
private Log _log;
private ErrorLog _errorLog;
private List _tasks;
private Messages _messages;
/**
* Orders the {@link #setTasks(List) tasks}into an execution order, and executes each in turn.
* Logs the elapsed time, number of tasks, and the number of failures (if any).
*/
public void run()
{
long startTime = System.currentTimeMillis();
Orderer orderer = new Orderer(_errorLog, task());
Iterator i = _tasks.iterator();
while (i.hasNext())
{
Task t = (Task) i.next();
orderer.add(t, t.getId(), t.getAfter(), t.getBefore());
}
List orderedTasks = orderer.getOrderedObjects();
int failures = 0;
i = orderedTasks.iterator();
while (i.hasNext())
{
Task t = (Task) i.next();
if (!execute(t))
failures++;
}
long elapsedTime = System.currentTimeMillis() - startTime;
if (failures == 0)
_log.info(success(orderedTasks.size(), elapsedTime));
else
_log.info(failure(failures, orderedTasks.size(), elapsedTime));
}
/**
* Execute a single task.
*
* @return true on success, false on failure
*/
private boolean execute(Task t)
{
_log.info(executingTask(t));
try
{
t.execute();
return true;
}
catch (Exception ex)
{
_errorLog.error(exceptionInTask(t, ex), t.getLocation(), ex);
return false;
}
}
private String task()
{
return _messages.getMessage("task");
}
private String executingTask(Task t)
{
return _messages.format("executing-task", t.getTitle());
}
private String exceptionInTask(Task t, Throwable cause)
{
return _messages.format("exception-in-task", t.getTitle(), cause);
}
private String success(int count, long elapsedTimeMillis)
{
return _messages.format("success", new Integer(count), new Long(elapsedTimeMillis));
}
private String failure(int failureCount, int totalCount, long elapsedTimeMillis)
{
return _messages.format(
"failure",
new Integer(failureCount),
new Integer(totalCount),
new Long(elapsedTimeMillis));
}
public void setLog(Log log)
{
_log = log;
}
public void setErrorLog(ErrorLog errorLog)
{
_errorLog = errorLog;
}
public void setMessages(Messages messages)
{
_messages = messages;
}
public void setTasks(List list)
{
_tasks = list;
}
}