ActiveMQ example source code file (ClassLoaderSPIConnectionFactory.java)

This example ActiveMQ source code file (ClassLoaderSPIConnectionFactory.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

adding, cannot, classloader, connectionfactory, connectionfactory, exception, exception, file, file, io, logger, net, network, spiconnectionfactory, string, string, stringtokenizer, util

The ActiveMQ ClassLoaderSPIConnectionFactory.java source code

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package org.apache.activemq.tool.spi;

import java.io.File;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import java.util.StringTokenizer;

import javax.jms.ConnectionFactory;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public abstract class ClassLoaderSPIConnectionFactory implements SPIConnectionFactory {

    public static final String KEY_EXT_DIR = "extDir";
    private static final Logger LOG = LoggerFactory.getLogger(ClassLoaderSPIConnectionFactory.class);

    public final ConnectionFactory createConnectionFactory(Properties settings) throws Exception {

        // Load new context class loader
        ClassLoader newClassLoader = getContextClassLoader(settings);
        Thread.currentThread().setContextClassLoader(newClassLoader);

        return instantiateConnectionFactory(settings);
    }

    protected ClassLoader getContextClassLoader(Properties settings) {
        String extDir = (String)settings.remove(KEY_EXT_DIR);
        if (extDir != null) {
            StringTokenizer tokens = new StringTokenizer(extDir, ";,");
            List<URL> urls = new ArrayList();
            while (tokens.hasMoreTokens()) {
                String dir = tokens.nextToken();
                try {
                    File f = new File(dir);
                    if (!f.exists()) {
                        LOG.warn("Cannot find extension dir: " + f.getAbsolutePath());
                    } else {
                        LOG.info("Adding extension dir: " + f.getAbsolutePath());

                        urls.add(f.toURL());

                        File[] files = f.listFiles();
                        if (files != null) {
                            for (int j = 0; j < files.length; j++) {
                                if (files[j].getName().endsWith(".zip") || files[j].getName().endsWith(".jar")) {
                                    LOG.info("Adding extension dir: " + files[j].getAbsolutePath());
                                    urls.add(files[j].toURL());
                                }
                            }
                        }
                    }
                } catch (Exception e) {
                    LOG.warn("Failed to load ext dir: " + dir + ". Reason: " + e);
                }
            }

            URL u[] = new URL[urls.size()];
            urls.toArray(u);
            return new URLClassLoader(u, Thread.currentThread().getContextClassLoader());
        }
        return ClassLoaderSPIConnectionFactory.class.getClassLoader();
    }

    protected abstract ConnectionFactory instantiateConnectionFactory(Properties settings) throws Exception;
}