/*
* 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.axiom.attachments.lifecycle.impl;
import java.io.File;
import java.io.IOException;
import java.util.Observable;
import java.util.Observer;
import javax.activation.DataHandler;
import javax.activation.DataSource;
import org.apache.axiom.attachments.CachedFileDataSource;
import org.apache.axiom.attachments.lifecycle.DataHandlerExt;
import org.apache.axiom.attachments.lifecycle.LifecycleManager;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
public class DataHandlerExtImpl extends DataHandler implements
DataHandlerExt, Observer {
private static final Log log = LogFactory.getLog(DataHandlerExtImpl.class);
private DataHandler dataHandler = null;
private LifecycleManager manager = null;
private static int READ_COUNT = 1;
private boolean deleteOnreadOnce = false;
public DataHandlerExtImpl(DataHandler dataHandler, LifecycleManager manager){
super(dataHandler.getDataSource());
this.dataHandler = dataHandler;
this.manager = manager;
}
public void deleteWhenReadOnce() throws IOException {
deleteOnreadOnce = true;
FileAccessor fa =manager.getFileAccessor(getName());
if(fa==null){
log.warn("Could not find FileAccessor, delete on readOnce Failed");
return;
}
if(fa.getAccessCount() >= READ_COUNT){
purgeDataSource();
}else{
fa.addObserver(this);
}
}
public void purgeDataSource() throws IOException {
if(log.isDebugEnabled()){
log.debug("Start purgeDataSource");
}
File file = getFile();
if(file!=null){
//Invoke delete from LifecycleManager
manager.delete(file);
//If file was registered with VMShutdown hook
//lets remove it from the list to be deleted on VMExit.
VMShutdownHook hook =VMShutdownHook.hook();
if(hook.isRegistered()){
hook.remove(file);
}
if(log.isDebugEnabled()){
log.debug("File Purged and removed from Shutdown Hook Collection");
}
}else{
if(log.isDebugEnabled()){
log.debug("DataSource is not a CachedFileDataSource, Unable to Purge.");
}
}
if(log.isDebugEnabled()){
log.debug("End purgeDataSource");
}
}
public void update(Observable o, Object arg) {
try{
if(log.isDebugEnabled()){
log.debug("Start update in Observer");
}
if(o instanceof FileAccessor){
FileAccessor fa = (FileAccessor)o;
if(deleteOnreadOnce && fa.getAccessCount()>=READ_COUNT){
purgeDataSource();
}
}
}catch(IOException e){
if(log.isDebugEnabled()){
log.debug("delete on readOnce Failed");
}
log.warn("delete on readOnce Failed with IOException in Observer"+e.getMessage());
}
if(log.isDebugEnabled()){
log.debug("End update in Observer");
}
}
private File getFile(){
//get DataSource from DataHandler
DataSource dataSource = dataHandler.getDataSource();
if(dataSource instanceof CachedFileDataSource){
CachedFileDataSource cds = (CachedFileDataSource)dataSource;
//get the file object from data source.
return cds.getFile();
}
return null;
}
}