/*******************************************************************************
* Copyright (c) 1998, 2013 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.internal.eis.adapters.xmlfile;
import java.io.*;
import java.util.*;
import javax.resource.*;
import javax.resource.cci.*;
import org.eclipse.persistence.eis.EISDOMRecord;
/**
* Transaction to XML file JCA adapter.
* Transaction are supported to a limited degree through writing the doms to the file system on commit.
*
* @author James
* @since OracleAS TopLink 10<i>g</i> (10.0.3)
*/
public class XMLFileTransaction implements LocalTransaction {
protected boolean isInTransaction;
protected Map domFiles;
protected XMLFileConnection connection;
/**
* Default constructor.
*/
public XMLFileTransaction(XMLFileConnection connection) {
this.connection = connection;
this.isInTransaction = false;
}
/**
* Record that a transaction has begun.
*/
public void begin() {
this.isInTransaction = true;
this.domFiles = new HashMap(10);
}
/**
* Return if currently within a transaction.
*/
public boolean isInTransaction() {
return isInTransaction;
}
/**
* Write each of the transactional DOM records back to their files.
*/
public void commit() throws ResourceException {
try {
// store any dom to their files
for (Iterator doms = domFiles.entrySet().iterator(); doms.hasNext();) {
Map.Entry entry = (Map.Entry)doms.next();
String fileName = (String)entry.getKey();
EISDOMRecord record = (EISDOMRecord)entry.getValue();
Writer fileWriter = new FileWriter(fileName);
record.transformToWriter(fileWriter);
fileWriter.flush();
fileWriter.close();
}
} catch (Exception exception) {
throw new ResourceException(exception.toString());
}
this.domFiles = new HashMap(10);
this.isInTransaction = false;
}
/**
* Throw away each of the DOM records in the transactional cache.
*/
public void rollback() {
// throw away doms
this.domFiles = new HashMap(10);
this.isInTransaction = false;
}
/**
* Return the transactional copy of the file's DOM record.
* This will be written on commit.
*/
public EISDOMRecord retrieveDOMRecord(File file) throws Exception {
// Check for transactional copy.
EISDOMRecord fileRecord = (EISDOMRecord)this.domFiles.get(file.getPath());
if (fileRecord == null) {
// If the file exists parse it, otherwise create a new record.
if (file.exists()) {
Reader fileReader = new FileReader(file);
fileRecord = new EISDOMRecord();
// Parse file.
fileRecord.transformFromXML(fileReader);
fileReader.close();
} else {
fileRecord = new EISDOMRecord();
fileRecord.setDOM(fileRecord.createNewDocument("root"));
}
this.domFiles.put(file.getPath(), fileRecord);
}
return fileRecord;
}
}