Java tutorial
/*************************************************************** * This file is part of the [fleXive](R) framework. * * Copyright (c) 1999-2014 * UCS - unique computing solutions gmbh (http://www.ucs.at) * All rights reserved * * The [fleXive](R) project is free software; you can redistribute * it and/or modify it under the terms of the GNU Lesser General Public * License version 2.1 or higher as published by the Free Software Foundation. * * The GNU Lesser General Public License can be found at * http://www.gnu.org/licenses/lgpl.html. * A copy is found in the textfile LGPL.txt and important notices to the * license from the author are found in LICENSE.txt distributed with * these libraries. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * For further information about UCS - unique computing solutions gmbh, * please see the company website: http://www.ucs.at * * For further information about [fleXive](R), please see the * project website: http://www.flexive.org * * * This copyright notice MUST APPEAR in all copies of the file! ***************************************************************/ package com.flexive.core.stream; import com.flexive.core.Database; import com.flexive.core.storage.StorageManager; import com.flexive.core.storage.binary.BinaryInputStream; import com.flexive.shared.FxContext; import com.flexive.shared.FxSharedUtils; import com.flexive.shared.exceptions.FxNotFoundException; import com.flexive.shared.media.FxMediaEngine; import com.flexive.shared.stream.BinaryDownloadPayload; import com.flexive.shared.structure.TypeStorageMode; import com.flexive.shared.value.BinaryDescriptor; import com.flexive.stream.DataPacket; import com.flexive.stream.StreamException; import com.flexive.stream.StreamProtocol; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.io.IOException; import java.nio.ByteBuffer; import java.sql.Connection; import java.sql.SQLException; /** * Stream protocol to download binaries * * @author Markus Plesser (markus.plesser@flexive.com), UCS - unique computing solutions gmbh (http://www.ucs.at) */ public class BinaryDownloadProtocol extends StreamProtocol<BinaryDownloadPayload> { protected static final Log LOG = LogFactory.getLog(BinaryDownloadProtocol.class); private Connection con; private BinaryInputStream bin; private byte[] _buffer; private int pre_read = 0; /** * Ctor */ public BinaryDownloadProtocol() { super(BinaryDownloadPayload.class); } /** * {@inheritDoc} */ @Override public StreamProtocol<BinaryDownloadPayload> getInstance() { return new BinaryDownloadProtocol(); } /** * {@inheritDoc} */ @Override public boolean canHandle(DataPacket<BinaryDownloadPayload> dataPacket) throws StreamException { return true; } /** * {@inheritDoc} */ @Override public DataPacket<BinaryDownloadPayload> processPacket(DataPacket<BinaryDownloadPayload> dataPacket) throws StreamException { if (dataPacket.isExpectResponse() && dataPacket.isExpectStream()) { String mimeType; int datasize; final BinaryDescriptor.PreviewSizes previewSize = BinaryDescriptor.PreviewSizes .fromSize(dataPacket.getPayload().getSize()); try { con = Database.getNonTXDataSource(dataPacket.getPayload().getDivision()).getConnection(); bin = loadBinaryDescriptor(dataPacket, previewSize); if (dataPacket.getPayload().isForceImage() && previewSize == BinaryDescriptor.PreviewSizes.ORIGINAL && !bin.getMimeType().startsWith("image")) { // choose biggest preview size if an image is required, but the binary is no image bin = loadBinaryDescriptor(dataPacket, BinaryDescriptor.PreviewSizes.SCREENVIEW); } } catch (NullPointerException e) { //FX-782, loadBinaryDescriptor failed return new DataPacket<BinaryDownloadPayload>(new BinaryDownloadPayload(true, "ex.stream.notFound"), false); } catch (FxNotFoundException e) { LOG.error("Failed to lookup content storage for division #" + dataPacket.getPayload().getDivision() + ": " + e.getLocalizedMessage()); return new DataPacket<BinaryDownloadPayload>(new BinaryDownloadPayload(true, "ex.stream.notFound"), false); } catch (SQLException e) { throw new StreamException("Database connection error: " + e.getMessage(), e); } if (bin == null || !bin.isBinaryFound()) return new DataPacket<BinaryDownloadPayload>(new BinaryDownloadPayload(true, "ex.stream.notFound"), false); mimeType = bin.getMimeType(); datasize = bin.getSize(); _buffer = new byte[4096]; if (!mimeType.startsWith("image")) { try { pre_read = bin.read(_buffer, 0, 100); } catch (IOException e) { //silently ignore } String tmp = FxMediaEngine.detectMimeType(_buffer); if (tmp.startsWith("image")) mimeType = tmp; } else pre_read = 0; return new DataPacket<BinaryDownloadPayload>(new BinaryDownloadPayload(mimeType, datasize), false); } return null; } private BinaryInputStream loadBinaryDescriptor(DataPacket<BinaryDownloadPayload> dataPacket, BinaryDescriptor.PreviewSizes previewSize) throws FxNotFoundException { // set division information in context for the storage engine FxContext.get().setDivisionId(dataPacket.getPayload().getDivision()); BinaryInputStream o = StorageManager.getContentStorage(TypeStorageMode.Hierarchical).fetchBinary(con, dataPacket.getPayload().getDivision(), previewSize, dataPacket.getPayload().getId(), dataPacket.getPayload().getVersion(), dataPacket.getPayload().getQuality()); if (!o.isBinaryFound()) { Database.closeObjects(BinaryDownloadProtocol.class, con, null); } return o; } /** * {@inheritDoc} */ @Override public void closeResources() { FxSharedUtils.close(bin); Database.closeObjects(BinaryDownloadProtocol.class, con, null); } /** * {@inheritDoc} */ @Override public boolean sendStream(ByteBuffer buffer) throws IOException { if (buffer.remaining() <= 0 || bin == null) return true; //should not happen but possible ... if (pre_read > 0) { buffer.put(_buffer, 0, pre_read); //size should not matter since its only 100 bytes pre_read = 0; } int max = Math.min(buffer.remaining(), _buffer.length); int read = bin.read(_buffer, 0, max); if (read == -1) { return false; } buffer.put(_buffer, 0, read); return true; } }