com.smash.revolance.ui.model.application.ApplicationFactory.java Source code

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Here is the source code for com.smash.revolance.ui.model.application.ApplicationFactory.java

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package com.smash.revolance.ui.model.application;

/*
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Revolance-UI-Model
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Copyright (C) 2012 - 2013 RevoLance
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * 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/gpl-3.0.html>.
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

import com.smash.revolance.ui.model.helper.JarClassLoader;
import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.jar.Attributes;
import java.util.jar.JarFile;
import java.util.jar.Manifest;

/**
 * User: wsmash
 * Date: 01/06/13
 * Time: 00:44
 */
public class ApplicationFactory {
    private Map<String, Application> applicationInstances = new HashMap<String, Application>();
    private Map<String, ClassLoader> applicationLoaders = new HashMap<String, ClassLoader>();

    public Application buildApplication(ApplicationConfiguration setup)
            throws NoSuchMethodException, IllegalAccessException, InstantiationException, IOException,
            InvocationTargetException, ClassNotFoundException {
        Application app = getApplication(setup.getId(), setup.getApplicationDir(),
                setup.getApplicationImplementation(), setup.getApplicationVersion());

        return app;
    }

    private Class loadClass(String appDir, String appId, String impl, String version)
            throws ClassNotFoundException, IOException {
        ClassLoader loader = getLoader(appDir, appId, impl, version);
        if (loader == null) {
            loader = Thread.currentThread().getContextClassLoader();
        }
        return loader.loadClass(impl);
    }

    private Application getApplication(String appId, String appDir, String impl, String version)
            throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InvocationTargetException,
            InstantiationException, IOException {
        if (!applicationInstances.containsKey(getKey(appId, impl, version))) {
            Class applicationClass = loadClass(appDir, appId, impl, version);
            Application application = (Application) applicationClass.getDeclaredConstructor().newInstance();
            applicationInstances.put(getKey(appId, impl, version), application);
        }
        return applicationInstances.get(getKey(appId, impl, version));
    }

    private ClassLoader getLoader(String appDir, String appId, String impl, String version) throws IOException {
        if (!applicationLoaders.containsKey(getKey(appId, impl, version))) {
            loadApplication(appDir, appId, impl, version);
        }
        return applicationLoaders.get(getKey(appId, impl, version));
    }

    private String getKey(String appId, String impl, String version) {
        return appId + "[" + impl + (version == null ? "" : "#" + version);
    }

    private void loadApplication(String appDir, String appId, String impl, String version) throws IOException {
        if (!appDir.isEmpty() && new File(appDir).isDirectory()) {
            Collection<File> files = FileUtils.listFiles(new File(appDir), new String[] { "jar" }, false);

            for (File file : files) {
                JarFile jar = new JarFile(file);
                Manifest manifest = jar.getManifest();
                Attributes attributes = manifest.getMainAttributes();

                String implAttr = attributes.getValue("revolance-ui-explorer-applicationImpl");
                String versionAttr = attributes.getValue("revolance-ui-explorer-applicationVersion");

                if (implAttr.contentEquals(impl) && (versionAttr.contentEquals(version) || version == null)) {
                    applicationLoaders.put(getKey(appId, impl, version), new JarClassLoader(file.toURI().toURL()));
                }
            }

        }
    }
}