Java tutorial
/* * Copyright (c) 2006-2011 Nuxeo SA (http://nuxeo.com/) and others. * * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * bstefanescu */ package org.eclipse.ecr.runtime.model.persistence.fs; import java.io.ByteArrayInputStream; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.List; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.eclipse.ecr.runtime.model.persistence.Contribution; import org.eclipse.ecr.runtime.model.persistence.ContributionStorage; import org.nuxeo.common.Environment; import org.nuxeo.common.utils.FileUtils; import org.nuxeo.common.xmap.DOMSerializer; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; /** * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a> * */ public class FileSystemStorage implements ContributionStorage { public static final Log log = LogFactory.getLog(FileSystemStorage.class); protected static final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); protected final File root; public FileSystemStorage() { root = new File(Environment.getDefault().getData(), "contribs"); root.mkdirs(); } public static synchronized String safeRead(File file) throws IOException { return FileUtils.readFile(file); } public static synchronized void safeWrite(File file, String content) throws IOException { FileUtils.writeFile(file, content); } public static synchronized boolean safeCreate(File file, String content) throws IOException { if (file.isFile()) { return false; } FileUtils.writeFile(file, content); return true; } public static synchronized boolean safeRemove(File file) throws IOException { return file.delete(); } public static void loadMetadata(Contribution contrib) { try { DocumentBuilder docBuilder = factory.newDocumentBuilder(); Document doc = docBuilder.parse(new ByteArrayInputStream(contrib.getContent().getBytes())); Element root = doc.getDocumentElement(); contrib.setDisabled(Boolean.parseBoolean(root.getAttribute("disabled"))); Node node = root.getFirstChild(); while (node != null) { if (node.getNodeType() == Node.ELEMENT_NODE && "documentation".equals(node.getNodeName())) { break; } node = node.getNextSibling(); } if (node != null) { node = node.getFirstChild(); StringBuilder buf = new StringBuilder(); while (node != null) { if (node.getNodeType() == Node.TEXT_NODE) { buf.append(node.getNodeValue()); } node = node.getNextSibling(); } contrib.setDescription(buf.toString().trim()); } else { contrib.setDescription(""); } } catch (Exception e) { log.error("Failed to read contribution metadata", e); } } @Override public Contribution addContribution(Contribution contribution) throws Exception { File file = new File(root, contribution.getName() + ".xml"); String content = contribution.getContent(); if (safeCreate(file, content)) { return new ContributionFile(contribution.getName(), file); } return null; } @Override public Contribution getContribution(String name) { File file = new File(root, name + ".xml"); if (file.isFile()) { return new ContributionFile(name, file); } return null; } @Override public List<Contribution> getContributions() { List<Contribution> result = new ArrayList<Contribution>(); File[] files = root.listFiles(); if (files == null) { return result; } for (File file : files) { String name = file.getName(); if (name.endsWith(".xml")) { name = name.substring(0, name.length() - 4); result.add(new ContributionFile(name, file)); } } return result; } @Override public boolean removeContribution(Contribution contrib) throws Exception { return safeRemove(new File(root, contrib.getName() + ".xml")); } @Override public Contribution updateContribution(Contribution contribution) throws Exception { File file = new File(root, contribution.getName() + ".xml"); String content = safeRead(file); DocumentBuilder docBuilder = factory.newDocumentBuilder(); Document doc = docBuilder.parse(new ByteArrayInputStream(content.getBytes())); Element root = doc.getDocumentElement(); if (contribution.isDisabled()) { root.setAttribute("disabled", "true"); } else { root.removeAttribute("disabled"); } Node node = root.getFirstChild(); while (node != null) { if (node.getNodeType() == Node.ELEMENT_NODE && "documentation".equals(node.getNodeName())) { break; } node = node.getNextSibling(); } String description = contribution.getDescription(); if (description == null) { description = ""; } if (node != null) { root.removeChild(node); } Element el = doc.createElement("documentation"); el.appendChild(doc.createTextNode(description)); root.appendChild(el); safeWrite(file, DOMSerializer.toString(doc)); return getContribution(contribution.getName()); } }