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: * Nuxeo - initial API and implementation * * $Id$ */ package org.eclipse.ecr.runtime.api; import javax.naming.CompositeName; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NamingException; import javax.naming.Reference; import javax.naming.spi.NamingManager; import javax.sql.DataSource; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * Helper class to look up {@link DataSource}s without having to deal with * vendor-specific JNDI prefixes. * * @author Thierry Delprat * @author Florent Guillaume */ public class DataSourceHelper { private DataSourceHelper() { } protected static final class TestingInitialContext extends InitialContext { protected TestingInitialContext() throws NamingException { super(false); // lazy mode is breaking jboss } // subclass in order to access the protected method @Override public Context getDefaultInitCtx() throws NamingException { return super.getDefaultInitCtx(); } } private static final Log log = LogFactory.getLog(DataSourceHelper.class); public static final String PREFIX_PROPERTY = "org.eclipse.ecr.runtime.datasource.prefix"; public static final String DEFAULT_PREFIX = "java:comp/env/jdbc"; protected static String prefix; public static void autodetectPrefix() { Context ctx = getDefaultInitCtx(); String name = ctx == null ? null : ctx.getClass().getName(); if ("org.nuxeo.common.jndi.NamingContext".equals(name)) { // Nuxeo-Embedded prefix = DEFAULT_PREFIX; } else if ("org.jnp.interfaces.NamingContext".equals(name)) { // JBoss prefix = "java:"; } else if ("org.apache.naming.SelectorContext".equals(name)) { // Tomcat prefix = DEFAULT_PREFIX; } else if ("org.mortbay.naming.local.localContextRoot".equals(name)) { // Jetty prefix = "jdbc"; } else if ("com.sun.enterprise.naming.impl.SerialContext".equals(name)) { // GlassFish prefix = DEFAULT_PREFIX; } else { // unknown, use Java EE standard log.error("Unknown JNDI Context class: " + name); prefix = DEFAULT_PREFIX; } log.info("Using JDBC JNDI prefix: " + prefix); } public static Context getDefaultInitCtx() { try { return new TestingInitialContext().getDefaultInitCtx(); } catch (NamingException e) { return null; } } /** * Get the JNDI prefix used for DataSource lookups. */ public static String getDataSourceJNDIPrefix() { if (prefix == null) { if (Framework.isInitialized()) { String configuredPrefix = Framework.getProperty(PREFIX_PROPERTY); if (configuredPrefix != null) { prefix = configuredPrefix; } else { autodetectPrefix(); } } else { prefix = DEFAULT_PREFIX; } } return prefix; } /** * Look up a datasource JNDI name given a partial name. * <p> * For a datasource {@code "jdbc/foo"}, then it's sufficient to pass {@code * "foo"} to this method. * * @param partialName the partial name * @return the datasource JNDI name */ public static String getDataSourceJNDIName(String partialName) { String targetPrefix = getDataSourceJNDIPrefix(); // keep suffix only (jdbc/foo -> foo) int idx = partialName.lastIndexOf("/"); if (idx > 0) { partialName = partialName.substring(idx + 1); } // add prefix return targetPrefix + "/" + partialName; } /** * Look up a datasource given a partial name. * <p> * For a datasource {@code "jdbc/foo"}, then it's sufficient to pass {@code * "foo"} to this method. * * @param partialName the partial name * @return the datasource * @throws NamingException */ public static DataSource getDataSource(String partialName) throws NamingException { String jndiName = getDataSourceJNDIName(partialName); InitialContext context = new InitialContext(); Object resolved = context.lookup(jndiName); if (resolved instanceof Reference) { try { resolved = NamingManager.getObjectInstance(resolved, new CompositeName(jndiName), context, null); } catch (Exception e) { throw new Error("Cannot get access to " + jndiName, e); } } return (DataSource) resolved; } }