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.padaf.xmpbox; import java.io.IOException; import java.io.OutputStream; import javax.xml.transform.TransformerException; import org.apache.commons.io.IOUtils; import org.apache.commons.io.output.ByteArrayOutputStream; import org.apache.padaf.xmpbox.parser.XMLUtil; import org.apache.padaf.xmpbox.schema.XMPSchema; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.ProcessingInstruction; /** * This class represents tools to save metadata and schema in serialized way * (RDF/XML Format) * * @author a183132 * */ public class SaveMetadataHelper { /** * According to check-style, Utility classes should not have a public or * default constructor. */ protected SaveMetadataHelper() { }; /** * Prepare XMP Saving Put data necessary to make a well-formed XMP * * @param metadata * metadata concerned by the serialization processing * @param intoXPacket * true if Processing instruction must be embedded * @return The DOM Document which will represent the serialized metadata */ protected static Document prepareSaving(XMPMetadata metadata, boolean intoXPacket) { Document newdoc = (Document) metadata.getFuturOwner().cloneNode(true); if (intoXPacket) { ProcessingInstruction beginXPacket = newdoc.createProcessingInstruction("xpacket", "begin=\"" + metadata.getXpacketBegin() + "\" id=\"" + metadata.getXpacketId() + "\""); newdoc.appendChild(beginXPacket); } Element xmpMeta = newdoc.createElementNS("adobe:ns:meta/", "x:xmpmeta"); xmpMeta.setAttributeNS(XMPSchema.NS_NAMESPACE, "xmlns:x", "adobe:ns:meta/"); newdoc.appendChild(xmpMeta); Element elem = (Element) metadata.getContainerElement().cloneNode(true); newdoc.adoptNode(elem); xmpMeta.appendChild(elem); if (intoXPacket) { ProcessingInstruction endXPacket = newdoc.createProcessingInstruction("xpacket", metadata.getEndXPacket()); newdoc.appendChild(endXPacket); } return newdoc; } /** * Serialize metadata into an output stream with XPacket PI * * @param metadata * Metadata concerned by the serialization processing * @param os * Stream to save serialized metadata * @throws TransformException * When couldn't parse data to XML/RDF */ public static void serialize(XMPMetadata metadata, OutputStream os) throws TransformException { serialize(metadata, true, os); } /** * Serialize metadata into an output stream * * @param metadata * Metadata concerned by the serialization processing * @param intoXPacket * True to put XPacket Processing Information * @param os * Stream to save serialized metadata * @throws TransformException * When couldn't parse data to XML/RDF */ public static void serialize(XMPMetadata metadata, boolean intoXPacket, OutputStream os) throws TransformException { Document doc = prepareSaving(metadata, intoXPacket); try { XMLUtil.save(doc, os, "UTF-8"); } catch (TransformerException e) { throw new TransformException("Failed to parse defined XMP", e); } } /** * Serialize metadata into the byte array returned * * @param metadata * Metadata concerned by the serialization processing * @param intoXPacket * True to put XPacket Processing Information * @return ByteArray which contains serialized metadata * @throws TransformException * When couldn't parse data to XML/RDF */ public static byte[] serialize(XMPMetadata metadata, boolean intoXPacket) throws TransformException { ByteArrayOutputStream bos = new ByteArrayOutputStream(); serialize(metadata, intoXPacket, bos); IOUtils.closeQuietly(bos); return bos.toByteArray(); } /** * Serialize metadata with XPacket PI into the byte array returned * * @param metadata * Metadata concerned by the serialization processing * @return ByteArray which contains serialized metadata * @throws TransformException * When couldn't parse data to XML/RDF */ public static byte[] serialize(XMPMetadata metadata) throws TransformException { return serialize(metadata, true); } /** * Serialize a schema into an Output stream * * @param schema * Schema concerned by the serialization processing * @param os * Stream to save serialized schema * @throws TransformException * When couldn't parse data to XML/RDF */ public static void serialize(XMPSchema schema, OutputStream os) throws TransformException { try { Document doc = XMLUtil.newDocument(); Element rdf = doc.createElementNS("http://www.w3.org/1999/02/22-rdf-syntax-ns#", "rdf:RDF"); Node schemContent = schema.getElement().cloneNode(true); doc.adoptNode(schemContent); rdf.appendChild(schemContent); XMLUtil.save(rdf, os, "UTF-8"); } catch (TransformerException e) { throw new TransformException("Failed to parse defined XMP", e); } catch (IOException e) { throw new TransformException("Failed to create Document to contain Schema representation ", e); } } /** * Serialize a schema into a Byte Array * * @param schema * Schema concerned by the serialization processing * @return a ByteArray which contains serialized schema * @throws TransformException * When couldn't parse data to XML/RDF */ public static byte[] serialize(XMPSchema schema) throws TransformException { ByteArrayOutputStream bos = new ByteArrayOutputStream(); serialize(schema, bos); IOUtils.closeQuietly(bos); return bos.toByteArray(); } }