org.efaps.db.transaction.AbstractResource Maven / Gradle / Ivy
/*
* Copyright 2003 - 2012 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: 7483 $
* Last Changed: $Date: 2012-05-11 11:57:38 -0500 (Fri, 11 May 2012) $
* 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 7483 2012-05-11 16:57:38Z [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());
}
}
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