it.unipmn.di.dcs.sharegrid.web.management.ManagementEnv.java Source code

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Here is the source code for it.unipmn.di.dcs.sharegrid.web.management.ManagementEnv.java

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/*
 * Copyright (C) 2008  Distributed Computing System (DCS) Group, Computer
 * Science Department - University of Piemonte Orientale, Alessandria (Italy).
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

package it.unipmn.di.dcs.sharegrid.web.management;

import it.unipmn.di.dcs.sharegrid.web.management.naming.ManagementContextFactory;
import it.unipmn.di.dcs.sharegrid.web.management.naming.ManagementContextFactoryBuilder;

import java.util.Hashtable;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.naming.Reference;
import javax.naming.spi.NamingManager;
import javax.naming.StringRefAddr;

/**
 * Represents the environment for classes under the {@code management} package.
 *
 * @author <a href="mailto:marco.guazzone@gmail.com">Marco Guazzone</a>
 */
public final class ManagementEnv {
    private boolean initialized = false;
    private InitialContext initCtx = null;
    private ManagementContextFactoryBuilder ctxFactoryBuild = null;

    /** A constructor. */
    protected ManagementEnv() {
        // empty
    }

    /** Returns the sole instance. */
    public static ManagementEnv instance() {
        return ManagementEnvHolder.instance;
    }

    /** Initialize the environment. */
    public void init() throws ManagementException {
        if (this.initialized) {
            return;
        }

        this.initJNDI();
    }

    /** Initialized the JNDI. */
    protected void initJNDI() throws ManagementException {
        try {
            this.ctxFactoryBuild = new ManagementContextFactoryBuilder();
            NamingManager.setInitialContextFactoryBuilder(this.ctxFactoryBuild);
            NamingManager.setObjectFactoryBuilder(this.ctxFactoryBuild);

            // Initial environment with various properties
            Hashtable<String, String> env = new Hashtable<String, String>();
            env.put(Context.INITIAL_CONTEXT_FACTORY, ManagementContextFactory.class.getName());
            //env.put(Context.PROVIDER_URL, "");
            //env.put(Context.OBJECT_FACTORIES, "foo.bar.ObjFactory");
            env.put(Context.URL_PKG_PREFIXES, ManagementContextFactory.class.getPackage().getName());

            this.initCtx = new InitialContext(env);
            Context javaCompCtx = (Context) this.getOrCreateSubcontext("java:comp", initCtx);
            if (javaCompCtx == null) {
                throw new ManagementException("JNDI problem. Cannot get java:comp context from InitialContext.");
            }
            Context envCtx = (Context) this.getOrCreateSubcontext("env", javaCompCtx);
            if (envCtx == null) {
                throw new ManagementException("JNDI problem. Cannot get env context from java:comp context.");
            }
            Context jdbcCtx = (Context) this.getOrCreateSubcontext("jdbc", envCtx);
            if (jdbcCtx == null) {
                throw new ManagementException("JNDI problem. Cannot get jdbc context from java:comp/env context.");
            }

            // Create the DataSource

            //Properties properties = new Properties();
            //properties.put( "driverClassName", "com.mysql.jdbc.Driver" );
            //properties.put( "url", "jdbc:mysql://localhost:3306/DB" );
            //properties.put( "username", "username" );
            //properties.put( "password", "********" );
            //
            //DataSource dataSource = BasicDataSourceFactory.createDataSource( properties );
            //initContext.bind( "java:comp/env/jdbc/db", dataSource );

            //Reference ref = new Reference( "javax.sql.DataSource", "org.apache.commons.dbcp.BasicDataSourceFactory", null ); 
            //ref.add(new StringRefAddr("driverClassName", "com.mysql.jdbc.Driver"));
            //ref.add(new StringRefAddr("url", "jdbc:mysql://localhost:3306/sharegrid"));
            //ref.add(new StringRefAddr("username", "root"));
            //ref.add(new StringRefAddr("password", ""));
            //initCtx.rebind( "java:comp/env/jdbc/mysql", ref );
            java.util.Properties properties = new java.util.Properties();
            properties.put("driverClassName", "com.mysql.jdbc.Driver");
            properties.put("url", "jdbc:mysql://localhost:3306/sharegrid");
            properties.put("username", "root");
            properties.put("password", "");
            javax.sql.DataSource dataSource = org.apache.commons.dbcp.BasicDataSourceFactory
                    .createDataSource(properties);
            initCtx.rebind("java:comp/env/jdbc/mysql", dataSource);

        } catch (Exception ex) {
            throw new ManagementException("JNDI problem.", ex);
        }
    }

    /** Returns the given (sub-)context (eventually, creating it). */
    protected Context getOrCreateSubcontext(String contextName, Context context) throws NamingException {
        try {
            return (Context) context.lookup(contextName);
        } catch (Exception exp) {
            return context.createSubcontext(contextName);
        }
    }

    /** Holds the singleton instance. */
    private static final class ManagementEnvHolder {
        private final static ManagementEnv instance = new ManagementEnv();
    }
}