Java tutorial
/* * NOTE: This copyright does *not* cover user programs that use HQ * program services by normal system calls through the application * program interfaces provided as part of the Hyperic Plug-in Development * Kit or the Hyperic Client Development Kit - this is merely considered * normal use of the program, and does *not* fall under the heading of * "derived work". * * Copyright (C) [2004-2007], Hyperic, Inc. * This file is part of HQ. * * HQ is free software; you can redistribute it and/or modify * it under the terms version 2 of the GNU General Public License as * published by the Free Software Foundation. This program 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA. */ package org.hyperic.hq.hqu; import groovy.lang.GroovyClassLoader; import java.io.File; import java.io.IOException; import java.net.MalformedURLException; import java.util.Properties; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.hyperic.hq.authz.server.session.AuthzSubject; import org.hyperic.hq.authz.server.session.Resource; import org.hyperic.hq.common.SystemException; import org.hyperic.hq.hqu.server.session.Attachment; import org.hyperic.hq.hqu.server.session.UIPlugin; import org.hyperic.util.Runnee; import org.hyperic.util.file.FileUtil; /** * Basically a wrapper around the classloader and associated groovy artifacts. * * This class sets up the rendit_sys directory as a member of the classloader * hierarchy. In addition, any jars contained in pluginDir/lib will be added to * the classloader. */ public class PluginWrapper { private static final Log _log = LogFactory.getLog(PluginWrapper.class); private File _pluginDir; private final GroovyClassLoader _loader; private IDispatcher _dispatcher; /** * @return A unique temporary directory for embedded jar deployments. */ private File getTempDir() { String tmp = System.getProperty("java.io.tmpdir"); File tmpHquDir = new File(tmp, "hqu"); if (!tmpHquDir.exists()) { if (!tmpHquDir.mkdirs()) { throw new RuntimeException("Unable to create temporary directory " + tmpHquDir.getAbsolutePath()); } } return tmpHquDir; } PluginWrapper(File pluginDir, ClassLoader parentLoader) { GroovyClassLoader groovyLoader = new GroovyClassLoader(parentLoader); _pluginDir = pluginDir; try { File tmpDir = getTempDir(); File libDir = new File(_pluginDir, "lib"); if (libDir.isDirectory()) { File[] files = libDir.listFiles(); for (int i = 0; i < files.length; i++) { if (files[i].isFile() && files[i].getName().endsWith(".jar")) { String prefix = pluginDir.getName() + "-" + files[i].getName().substring(0, files[i].getName().length() - 4); File tmpJar = File.createTempFile(prefix, ".jar", tmpDir); FileUtil.copyFile(files[i], tmpJar); tmpJar.deleteOnExit(); groovyLoader.addURL(tmpJar.toURL()); _log.info("Added url [" + tmpJar.toURL() + "] to plugin [" + pluginDir + "]"); } } } } catch (MalformedURLException e) { throw new RuntimeException(e); } catch (IOException e) { throw new RuntimeException(e); } _loader = groovyLoader; } private Object doInContext(Runnee runnable) throws Exception { Thread curThread = Thread.currentThread(); ClassLoader oldLoader = curThread.getContextClassLoader(); try { curThread.setContextClassLoader(_loader); return runnable.run(); } finally { curThread.setContextClassLoader(oldLoader); } } void loadDispatcher() throws Exception { doInContext(new Runnee() { public Object run() throws Exception { try { Class c = _loader.loadClass("org.hyperic.hq.hqu.rendit.Dispatcher"); _dispatcher = (IDispatcher) c.newInstance(); } catch (Exception e) { _log.error("Unable to load groovy class: org.hyperic.hq.hqu.rendit.Dispatcher", e); } return null; } }); } Properties loadPlugin() { try { return (Properties) doInContext(new Runnee() { public Object run() { return _dispatcher.loadPlugin(_pluginDir); } }); } catch (Exception e) { throw new PluginLoadException("Unable to load plugin", e); } } void handleRequest(final Object request) { try { doInContext(new Runnee() { public Object run() { _dispatcher.handleRequest(request); return null; } }); } catch (Exception e) { _log.warn("Error handling request from " + _pluginDir, e); throw new SystemException(e); } } void deploy(final UIPlugin p) { try { doInContext(new Runnee() { public Object run() { _dispatcher.deploy(p); return null; } }); } catch (Exception e) { _log.warn("Error deploying from " + _pluginDir, e); } } AttachmentDescriptor getAttachmentDescriptor(final Attachment a, final Resource r, final AuthzSubject u) { try { return (AttachmentDescriptor) doInContext(new Runnee() { public Object run() { return _dispatcher.getAttachmentDescriptor(a, r, u); } }); } catch (Exception e) { _log.warn("Error getting attachment descriptor for " + _pluginDir, e); throw new SystemException(e); } } Object invokeMethod(final InvokeMethodInvocationBindings b) { try { return doInContext(new Runnee() { public Object run() { return _dispatcher.invokeMethod(b); } }); } catch (Exception e) { _log.warn("Error invoking method from " + _pluginDir, e); throw new SystemException(e); } } File getPluginDir() { return _pluginDir; } }