/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package org.apache.cocoon.components.modules.output;
import java.util.Iterator;
import java.util.Map;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.logger.Logger;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Session;
/**
* Abstraction layer to encapsulate different output
* destinations. Configuration option <key-prefix> defaults to
* "org.apache.cocoon.components.modules.output.OutputModule"+":"
*
* Can be used with different isolation-level: default is "0" being
* no isolation at all, values are immediately visible but are removed
* on a rollback; "1" keeps the values at a save place until either
* rollback or commit is called. Then values are either discarded or
* copied to the final destination.
*
* @author <a href="mailto:haul@apache.org">Christian Haul</a>
* @version CVS $Id$
*/
public class SessionAttributeOutputModule extends AbstractOutputModule {
public final String PREFIX = "org.apache.cocoon.components.modules.output.OutputModule";
public final String TRANS_PREFIX = "org.apache.cocoon.components.modules.output.OutputModule.SessionAttributeOutputModule.transient";
public final String ROLLBACK_LIST = "org.apache.cocoon.components.modules.output.OutputModule.SessionAttributeOutputModule.rollback";
/**
* communicate an attribute value to further processing logic.
* @param modeConf column's mode configuration from resource
* description. This argument is optional.
* @param objectModel The objectModel
* @param name The attribute's label, consisting of "table.column"
* or "table.column[index]" in case of multiple attributes of the
* same spec.
* @param value The attriute's value.
* */
public void setAttribute( Configuration modeConf, Map objectModel, String name, Object value ) {
if (this.settings.get("isolation-level","0").equals("1")) {
if (getLogger().isDebugEnabled())
getLogger().debug("setting transient ['"+name+"'] to ['"+value+"']");
this.transientSetAttribute(objectModel, TRANS_PREFIX, name, value);
} else {
// use read uncommitted isolation level
Session session = ObjectModelHelper.getRequest(objectModel).getSession();
name = getName(name);
if (!this.attributeExists(objectModel, ROLLBACK_LIST, name)) {
Object tmp = session.getAttribute(name);
this.transientSetAttribute(objectModel, ROLLBACK_LIST, name, tmp);
}
if (getLogger().isDebugEnabled())
getLogger().debug("setting ['"+name+"'] to ['"+value+"']");
session.setAttribute(name, value);
}
}
/**
* If a database transaction needs to rollback, this is called to
* inform the further processing logic about this fact. All
* already set attribute values are invalidated. <em>This is difficult
* because only the request object can be used to synchronize this
* and build some kind of transaction object. Beaware that sending
* your data straight to some beans or other entities could result
* in data corruption!</em>
* */
public void rollback( Configuration modeConf, Map objectModel, Exception e ) {
if (this.settings.get("isolation-level","0").equals("1")) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("rolling back");
}
this.rollback(objectModel, TRANS_PREFIX);
} else {
if (getLogger().isDebugEnabled()) {
getLogger().debug("start rolling back");
}
Session session = ObjectModelHelper.getRequest(objectModel).getSession();
Map rollbackList = this.prepareCommit(objectModel,ROLLBACK_LIST);
if (rollbackList != null) {
for (Iterator i = rollbackList.entrySet().iterator(); i.hasNext(); ) {
Map.Entry me = (Map.Entry)i.next();
String key = (String)me.getKey();
Object val = me.getValue();
if (val != null) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("rolling back ['" + key + "'] to ['" + val + "']");
}
session.setAttribute(key, val);
} else {
if (getLogger().isDebugEnabled()) {
getLogger().debug("rolling back ['" + key + "']");
}
session.removeAttribute(key);
}
}
}
}
if (getLogger().isDebugEnabled()) {
getLogger().debug("done rolling back");
}
String prefix = (String) this.settings.get("key-prefix", PREFIX);
if (!(prefix.equals(""))) {
ObjectModelHelper.getRequest(objectModel).getSession().setAttribute(prefix+":",e.getMessage());
} else {
ObjectModelHelper.getRequest(objectModel).getSession().setAttribute("errorMessage",e.getMessage());
}
}
/**
* Signal that the database transaction completed
* successfully. See notes on @link{rollback}.
* */
public void commit( Configuration modeConf, Map objectModel ) {
if (this.settings.get("isolation-level","0").equals("1")) {
Logger logger = getLogger();
if (logger.isDebugEnabled()) {
logger.debug("prepare commit");
}
Map aMap = this.prepareCommit(objectModel, TRANS_PREFIX);
if (aMap == null || aMap.isEmpty()) {
return;
}
String prefix = (String)this.settings.get("key-prefix", PREFIX );
if (prefix.length() > 0) {
prefix = prefix + ":";
} else {
prefix = null;
}
Session session = ObjectModelHelper.getRequest(objectModel).getSession();
for (Iterator i = aMap.entrySet().iterator(); i.hasNext(); ) {
Map.Entry me = (Map.Entry)i.next();
String key = (String)me.getKey();
Object value = me.getValue();
if (prefix != null) {
key = prefix + key;
}
if (logger.isDebugEnabled()) {
logger.debug("committing ['" + key + "'] to ['" + value + "']");
}
session.setAttribute(key, value);
}
if (logger.isDebugEnabled()) {
logger.debug("done commit");
}
} else {
if (getLogger().isDebugEnabled())
getLogger().debug("commit");
this.prepareCommit(objectModel, ROLLBACK_LIST);
}
}
protected String getName( String name ) {
String prefix = (String) this.settings.get("key-prefix", PREFIX );
return (prefix.length() == 0 ? name : prefix+":"+name);
}
}