package org.jboss.seam.async;
import java.io.Serializable;
import org.jboss.seam.bpm.BusinessProcess;
import org.jboss.seam.contexts.Contexts;
import org.jboss.seam.contexts.Lifecycle;
import org.jboss.seam.core.Init;
import org.jboss.seam.log.LogProvider;
import org.jboss.seam.log.Logging;
/**
* Something that happens asynchronously, and with a full
* set of Seam contexts, including propagation of the
* business process and task instances.
*
* @author Gavin King
*
*/
public abstract class Asynchronous implements Serializable
{
static final long serialVersionUID = -551286304424595765L;
private static transient final LogProvider log = Logging.getLogProvider(Asynchronous.class);
private Long processId;
private Long taskId;
public Asynchronous()
{
if ( Init.instance().isJbpmInstalled() )
{
BusinessProcess businessProcess = BusinessProcess.instance();
processId = businessProcess.getProcessId();
taskId = BusinessProcess.instance().getTaskId();
}
}
protected abstract class ContextualAsynchronousRequest
{
private Object timer;
private boolean createContexts;
public ContextualAsynchronousRequest(Object timer)
{
this.timer = timer;
this.createContexts = !Contexts.isEventContextActive() && !Contexts.isApplicationContextActive();
}
private void setup()
{
if (createContexts) Lifecycle.beginCall();
Contexts.getEventContext().set(AbstractDispatcher.EXECUTING_ASYNCHRONOUS_CALL, true);
if (taskId!=null)
{
BusinessProcess.instance().resumeTask(taskId);
}
else if (processId!=null)
{
BusinessProcess.instance().resumeProcess(processId);
}
if (timer!=null)
{
Contexts.getEventContext().set("timer", timer);
}
log.debug("executing: " + this);
}
protected abstract void process();
public void run()
{
setup();
try
{
process();
}
finally
{
cleanup();
}
}
private void cleanup()
{
Contexts.getEventContext().remove(AbstractDispatcher.EXECUTING_ASYNCHRONOUS_CALL);
if (createContexts) Lifecycle.endCall();
}
}
public abstract void execute(Object timer);
protected abstract void handleException(Exception exception, Object timer);
}