de.zib.gndms.infra.system.PluginLoader.java Source code

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Here is the source code for de.zib.gndms.infra.system.PluginLoader.java

Source

package de.zib.gndms.infra.system;
/*
 * Copyright 2008-2011 Zuse Institute Berlin (ZIB)
 *
 *  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.
 */

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;

/**
 * @author Maik Jorra
 * @email jorra@zib.de
 * @date 03.02.12  11:01
 * @brief
 */
public class PluginLoader {

    private String pluginPath;

    public PluginLoader(final String pluginPath) {
        this.pluginPath = pluginPath;
    }

    public URLClassLoader loadPlugins() throws IOException {

        final ArrayList<URL> jars;

        final File pluginDir = new File(pluginPath);

        final String[] list = pluginDir.list(new FilenameFilter() {
            @Override
            public boolean accept(final File dir, final String name) {

                return name.matches(".*\\.jar");
            }
        });

        if (list != null) {
            jars = new ArrayList<URL>(list.length);
            for (int i = 0; i < list.length; ++i)
                jars.add(new URL("file://" + pluginPath + File.separator + list[i]));

            return new URLClassLoader(jars.toArray(new URL[jars.size()]), this.getClass().getClassLoader());
        }

        return new URLClassLoader(new URL[] {}, this.getClass().getClassLoader());
    }

    public static void main(String[] args) throws Exception {

        if (args.length != 1) {
            System.out.println("java " + PluginLoader.class.getName() + " <plugin-dir>");
            System.exit(1);
        }

        ApplicationContext context = new ClassPathXmlApplicationContext("classpath:META-INF/00_system.xml");

        PluginLoader pl = new PluginLoader(args[0]);
        ClassLoader cl = pl.loadPlugins();
        PluggableTaskFlowProvider provider = (PluggableTaskFlowProvider) context.getAutowireCapableBeanFactory()
                .getBean("taskFlowProvider");

        provider.setCl(cl);
        provider.loadPlugins();
        provider.listPlugins();

        System.exit(0);
    }
}