Java tutorial
/* * 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.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.Observable; import javax.activation.DataHandler; import javax.mail.MessagingException; import org.apache.axiom.attachments.CachedFileDataSource; import org.apache.axiom.attachments.lifecycle.LifecycleManager; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * FileAccessor wraps the attachment temp file. It is created from PartOnFile. * The idea behind wrapping the file is to give rumtime an ability to track * when the file is accessed with streams or data handler and accordingly trigger * events to handle the the files lifecycle. * */ public class FileAccessor extends Observable { private static final Log log = LogFactory.getLog(FileAccessor.class); File file = null; LifecycleManager manager; private int accessCount = 0; public FileAccessor(LifecycleManager manager, File file) { super(); this.manager = manager; this.file = file; } public DataHandler getDataHandler(String contentType) throws MessagingException { if (log.isDebugEnabled()) { log.debug("getDataHandler()"); log.debug("accessCount =" + accessCount); } CachedFileDataSource dataSource = new CachedFileDataSource(file); dataSource.setContentType(contentType); accessCount++; setChanged(); notifyObservers(); DataHandler dataHandler = new DataHandler(dataSource); return new DataHandlerExtImpl(dataHandler, manager); } public String getFileName() throws MessagingException { if (log.isDebugEnabled()) { log.debug("getFileName()"); } return file.getAbsolutePath(); } public InputStream getInputStream() throws IOException, MessagingException { if (log.isDebugEnabled()) { log.debug("getInputStream()"); } return new FileInputStream(file); } public OutputStream getOutputStream() throws FileNotFoundException { if (log.isDebugEnabled()) { log.debug("getOutputStream()"); } return new FileOutputStream(file); } public long getSize() { return file.length(); } public File getFile() { return file; } public void setFile(File file) { this.file = file; } public int getAccessCount() { return accessCount; } }