Java tutorial
/* * (C) Copyright 2006-2016 Nuxeo SA (http://nuxeo.com/) and others. * * Licensed 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. * * Contributors: * bstefanescu */ package org.nuxeo.runtime.model.impl; import java.io.ByteArrayInputStream; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.util.Collections; import java.util.HashSet; import java.util.Set; import java.util.concurrent.locks.ReadWriteLock; import java.util.concurrent.locks.ReentrantReadWriteLock; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import org.apache.commons.io.FileUtils; import org.nuxeo.common.Environment; import org.nuxeo.runtime.model.RegistrationInfo; import org.nuxeo.runtime.model.RuntimeContext; import org.nuxeo.runtime.osgi.OSGiRuntimeService; import org.osgi.framework.Bundle; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.xml.sax.SAXException; /** * Manage persistent components. Persistent components are located in ${nxserver_data_dir}/components directory, and can * be dynamically removed or registered. After framework startup (after the application was completely started) the * persistent components are deployed. The layout of the components directory is the following: * * <pre> * components/ * component1.xml * component2.xml * ... * bundle_symbolicName1/ * component1.xml * component2.xml * ... * bundle_symbolicName1/ * ... * ... * </pre> * * If components are put directly under the root then they will be deployed in the runtime bundle context. If they are * put in a directory having as name the symbolicName of a bundle in the system, then the component will be deployed in * that bundle context. * <p> * Any files not ending with .xml are ignored. Any directory that doesn't match a bundle symbolic name will be ignored * too. * <p> * Dynamic components must use the following name convention: (it is not mandatory but it is recommended) * <ul> * <li>Components deployed in root directory must use as name the file name without the .xml extension. * <li>Components deployed in a bundle directory must use the relative file path without the .xml extensions. * </ul> * Examples: Given the following component files: <code>components/mycomp1.xml</code> and * <code>components/mybundle/mycomp2.xml</code> the name for <code>mycomp1</code> must be: <code>comp1</code> and for * <code>mycomp2</code> must be <code>mybundle/mycomp2</code> * <p> * This service is working only with {@link OSGiRuntimeService} * * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a> */ public class ComponentPersistence { protected final File root; // a directory to keep exploded extensions protected final RuntimeContext sysrc; protected final OSGiRuntimeService runtime; protected final ReadWriteLock fileLock; protected final Set<RegistrationInfo> persistedComponents; public ComponentPersistence(OSGiRuntimeService runtime) { this.runtime = runtime; root = new File(Environment.getDefault().getData(), "components"); fileLock = new ReentrantReadWriteLock(); sysrc = runtime.getContext(); persistedComponents = Collections.synchronizedSet(new HashSet<>()); } public File getRoot() { return root; } public final RuntimeContext getContext(String symbolicName) { if (symbolicName == null) { return sysrc; } Bundle bundle = runtime.getBundle(symbolicName); if (bundle == null) { return null; } return runtime.createContext(bundle); } protected void deploy(RuntimeContext rc, File file) throws IOException { RegistrationInfoImpl ri = (RegistrationInfoImpl) rc.deploy(file.toURI().toURL()); ri.isPersistent = true; } public void loadPersistedComponents() throws IOException { File[] files = root.listFiles(); if (files != null) { for (File file : files) { if (file.isDirectory()) { RuntimeContext rc = getContext(file.getName()); if (rc != null) { loadPersistedComponents(rc, file); } } else if (file.isFile() && file.getName().endsWith(".xml")) { deploy(sysrc, file); } } } } public void loadPersistedComponents(RuntimeContext rc, File root) throws IOException { File[] files = root.listFiles(); if (files != null) { for (File file : files) { if (file.isFile() && file.getName().endsWith(".xml")) { deploy(rc, file); } } } } public void loadPersistedComponent(File file) throws IOException { file = file.getCanonicalFile(); if (file.isFile() && file.getName().endsWith(".xml")) { File parent = file.getParentFile(); if (root.equals(parent)) { deploy(sysrc, file); return; } else { String symbolicName = parent.getName(); parent = parent.getParentFile(); if (root.equals(parent)) { RuntimeContext rc = getContext(symbolicName); if (rc != null) { deploy(rc, file); return; } } } } throw new IllegalArgumentException("Invalid component file location or bundle not found"); } public Document loadXml(File file) throws IOException { byte[] bytes = safeReadFile(file); return loadXml(new ByteArrayInputStream(bytes)); } public static Document loadXml(InputStream in) { DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); factory.setNamespaceAware(true); try { DocumentBuilder builder = factory.newDocumentBuilder(); return builder.parse(in); } catch (SAXException | IOException | ParserConfigurationException e) { throw new RuntimeException(e); } } public void createComponent(byte[] bytes) throws IOException { createComponent(bytes, true); } public synchronized void createComponent(byte[] bytes, boolean isPersistent) throws IOException { Document doc = loadXml(new ByteArrayInputStream(bytes)); Element root = doc.getDocumentElement(); String name = root.getAttribute("name"); int p = name.indexOf(':'); if (p > -1) { name = name.substring(p + 1); } p = name.indexOf('/'); String owner = null; if (p > -1) { owner = name.substring(0, p); } DefaultRuntimeContext rc = (DefaultRuntimeContext) getContext(owner); File file = new File(this.root, name + ".xml"); if (!isPersistent) { file.deleteOnExit(); } file.getParentFile().mkdirs(); safeWriteFile(bytes, file); rc.deploy(file.toURI().toURL()); } public synchronized boolean removeComponent(String compName) throws IOException { String path = compName + ".xml"; File file = new File(root, path); if (!file.isFile()) { return false; } int p = compName.indexOf('/'); String owner = null; if (p > -1) { owner = compName.substring(0, p); } DefaultRuntimeContext rc = (DefaultRuntimeContext) getContext(owner); rc.undeploy(file.toURI().toURL()); file.delete(); return true; } protected void safeWriteFile(byte[] bytes, File file) throws IOException { fileLock.writeLock().lock(); try { FileUtils.writeByteArrayToFile(file, bytes); } finally { fileLock.writeLock().unlock(); } } protected byte[] safeReadFile(File file) throws IOException { fileLock.readLock().lock(); try { return FileUtils.readFileToByteArray(file); } finally { fileLock.readLock().unlock(); } } }