package er.attachment.upload;
import java.io.File;
import com.webobjects.eocontrol.EOEditingContext;
import com.webobjects.eocontrol.EOGlobalID;
import er.attachment.model.ERAttachment;
import er.attachment.processors.ERAttachmentProcessor;
import er.extensions.concurrency.ERXAsyncQueue;
import er.extensions.eof.ERXEC;
import er.extensions.foundation.ERXExceptionUtilities;
/**
* The <code>ERAttachmentUploadQueue</code> is a queue to upload attachments.
* <p>
* Only <code>ERRemoteAttachment</code>s can be upload using this queue.
*
* @author <a href="mailto:hprange@gmail.com.br">Henrique Prange</a>
*
* @param <T>
* the type of the attachment that can queued for uploading.
*
* @see ERRemoteAttachment
*/
public abstract class ERAttachmentUploadQueue<T extends ERAttachment & ERRemoteAttachment> extends ERXAsyncQueue<ERAttachmentQueueEntry<T>> {
protected final ERAttachmentProcessor<T> _processor;
public ERAttachmentUploadQueue(String name, ERAttachmentProcessor<T> processor) {
super(name);
_processor = processor;
}
/**
* Adds an attachment to the end of the queue.
*
* @param attachment
* the attachment to upload
*/
public void enqueue(T attachment) {
EOEditingContext editingContext = attachment.editingContext();
editingContext.lock();
try {
EOGlobalID attachmentID = editingContext.globalIDForObject(attachment);
ERAttachmentQueueEntry<T> entry = new ERAttachmentQueueEntry<T>(attachment._pendingUploadFile(), attachmentID);
enqueue(entry);
} finally {
editingContext.unlock();
}
}
@Override
public void process(ERAttachmentQueueEntry<T> entry) {
EOEditingContext editingContext = ERXEC.newEditingContext();
T attachment = entry.attachment(editingContext);
File uploadedFile = entry.uploadedFile();
if (uploadedFile != null && uploadedFile.exists()) {
try {
performUpload(editingContext, attachment, uploadedFile);
editingContext.lock();
try {
attachment.setAvailable(Boolean.TRUE);
editingContext.saveChanges();
} finally {
editingContext.unlock();
}
if (_processor.delegate() != null) {
_processor.delegate().attachmentAvailable(_processor, attachment);
}
} catch (Throwable t) {
if (_processor.delegate() != null) {
_processor.delegate().attachmentNotAvailable(_processor, attachment, ERXExceptionUtilities.toParagraph(t));
}
ERAttachmentProcessor.log.error("Failed to upload '" + uploadedFile + "' to the remote server.", t);
} finally {
if (attachment._isPendingDelete()) {
uploadedFile.delete();
}
}
} else {
if (_processor.delegate() != null) {
_processor.delegate().attachmentNotAvailable(_processor, attachment, "Missing attachment file '" + uploadedFile + "'.");
}
ERAttachmentProcessor.log.error("Missing attachment file '" + uploadedFile + "'.");
}
}
/**
* Perform the upload of the attachment to the remote server.
*
* @param attachment
* the attachment to upload
* @param uploadedFile
* the file to upload
*/
protected abstract void performUpload(EOEditingContext editingContext, T attachment, File uploadedFile) throws Exception;
}