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eFaps is a framework used to map objects with or without attached files to
a relational database and optional file systems (only for attaches files). Configurable access control can be provided down to object and attribute level depending on implementation and use case. Depending on requirements, events (like triggers) allow to implement business logic and to separate business logic from user interface.
The framework includes integrations (e.g. webdav, full text search) and a web application as 'simple' configurable user interface. Some best practises, example web application modules (e.g. team work module) support administrators and implementers using this framework.
/*
* Copyright 2003 - 2011 The eFaps Team
*
* 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.
*
* Revision: $Rev: 6210 $
* Last Changed: $Date: 2011-02-18 16:02:56 -0500 (Fri, 18 Feb 2011) $
* Last Changed By: $Author: [email protected] $
*/
package org.efaps.db.transaction;
import javax.transaction.RollbackException;
import javax.transaction.SystemException;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.Xid;
import org.efaps.db.Context;
import org.efaps.util.EFapsException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Abstract class used to given an easy interface to implemented XA resources
* within the eFaps application.
* To use the implementation of such resource, it must be called first method
* {@link #open}. To free a resource of using, methods {@link #commit} (if all
* work was OK) or {@link #abort} (if the transaction must be rolled back) must
* be called.
*
* @author The eFaps Team
* @version $Id: AbstractResource.java 6210 2011-02-18 21:02:56Z [email protected] $
*/
public abstract class AbstractResource
implements XAResource
{
/**
* Logging instance used in this class.
*/
private static Logger LOG = LoggerFactory.getLogger(AbstractResource.class);
/**
* Is set to true if the connection resource is already enlisted in
* the transaction. Otherwise the value is false.
*/
private boolean opened = false;
/**
* Opens this connection resource and enlisted this resource in the
* transaction.
*
* @throws EFapsException if the resource is already opened or this
* resource could not be enlisted
*/
public void open() throws EFapsException
{
if (AbstractResource.LOG.isDebugEnabled()) {
AbstractResource.LOG.debug("open");
}
if (this.opened) {
AbstractResource.LOG.error("resource already opened");
throw new EFapsException(AbstractResource.class, "open.AlreadyOpened");
}
try {
final Context context = Context.getThreadContext();
context.getTransaction().enlistResource(this);
} catch (final RollbackException e) {
AbstractResource.LOG.error("exception occurs while delisting in transaction, "
+ "commit not possible", e);
throw new EFapsException(AbstractResource.class,
"open.RollbackException", e);
} catch (final SystemException e) {
AbstractResource.LOG.error("exception occurs while delisting in transaction, "
+ "commit not possible", e);
throw new EFapsException(AbstractResource.class,
"open.SystemException", e);
}
this.opened = true;
}
/**
* Closes this connection resource and delisted this resource in the
* transaction. The method must be called if the transaction should be
* commited.
*
* @throws EFapsException if the resource is not opened or this resource
* could not delisted
*/
public void commit() throws EFapsException
{
if (AbstractResource.LOG.isDebugEnabled()) {
AbstractResource.LOG.debug("commit");
}
if (!this.opened) {
AbstractResource.LOG.error("resource not opened, commit not possible");
throw new EFapsException(AbstractResource.class, "commit.NotOpened");
}
try {
final Context context = Context.getThreadContext();
context.getTransaction().delistResource(this, TMSUCCESS);
} catch (final SystemException e) {
AbstractResource.LOG.error("exception occurs while delisting in transaction, "
+ "commit not possible", e);
throw new EFapsException(AbstractResource.class,
"commit.SystemException", e);
}
freeResource();
this.opened = false;
}
/**
* Closes this XA resource and delisted this resource in the transaction.
*
* The method must be called if the transaction should be aborted (rolled
* back).
*
* @throws EFapsException if the resource is not opened or this resource
* could not delisted
*/
public void abort()
throws EFapsException
{
if (AbstractResource.LOG.isDebugEnabled()) {
AbstractResource.LOG.debug("abort");
}
if (!this.opened) {
throw new EFapsException(AbstractResource.class, "abort.NotOpened");
}
try {
final Context context = Context.getThreadContext();
context.getTransaction().delistResource(this, TMFAIL);
context.abort();
} catch (final SystemException e) {
throw new EFapsException(AbstractResource.class, "abort.SystemException", e);
}
freeResource();
this.opened = false;
}
/**
* Method used to free this resource in the eFaps context object (so that
* the resource instance could be reused).
*/
protected abstract void freeResource();
/**
* This is the getter method for instance variable {@link #opened}.
*
* @return true if this resource is open, otherwise
* false is returned.
* @see #opened
*/
public final boolean isOpened()
{
return this.opened;
}
/////////////////////////////////////////////////////////////////////////////
// all further methods are implementing javax.transaction.xa.XAResource
/**
* The method starts work on behalf of a transaction branch specified in
* parameter _xid. Normally nothing must be done, because the
* pre-work is already done in the contructor (and an instance of a
* resource is only defined for one transaction).
*
* @param _xid global transaction identifier
* @param _flags flags
*/
public void start(final Xid _xid,
final int _flags)
{
if (AbstractResource.LOG.isDebugEnabled()) {
AbstractResource.LOG.debug("start resource " + _xid + ", flags = " + _flags);
}
}
/**
* The method ends the work performed on behalf of a transaction branch.
* Normally nothing must be done, because an instance of a resource is only
* defined for one transaction.
*
* @param _xid global transaction identifier
* @param _flags flags
*/
public void end(final Xid _xid,
final int _flags)
{
if (AbstractResource.LOG.isDebugEnabled()) {
AbstractResource.LOG.debug("end resource " + _xid + ", flags = " + _flags);
}
}
/**
* The method is called from the transaction (manager) to check if the XA
* resource is the same as the given XA resource in the parameter
* _xaras. This is done with a string compare
* (method {@link String#equals(Object)}) off the
* {@link Object#toString()} methods of this and the XA resource in
* _xaras.
*
* @param _xares XA resource used to test if same resource
* @return true if the string compare returns that they are
* equal, otherwise false is returned
* @see XAResource#isSameRM(XAResource)
*/
public boolean isSameRM(final XAResource _xares)
{
if (AbstractResource.LOG.isDebugEnabled()) {
AbstractResource.LOG.debug("is Same RM " + _xares.toString().equals(toString()));
}
return _xares.toString().equals(toString());
}
}