de.xaniox.heavyspleef.addon.java.AddOnClassLoader.java Source code

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Here is the source code for de.xaniox.heavyspleef.addon.java.AddOnClassLoader.java

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/*
 * This file is part of HeavySpleef.
 * Copyright (c) 2014-2016 Matthias Werning
 *
 * 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 de.xaniox.heavyspleef.addon.java;

import com.google.common.collect.Maps;
import de.xaniox.heavyspleef.addon.AddOnManager;
import de.xaniox.heavyspleef.addon.AddOnProperties;
import de.xaniox.heavyspleef.addon.InvalidAddOnException;
import de.xaniox.heavyspleef.core.HeavySpleef;
import de.xaniox.heavyspleef.core.i18n.I18N;
import org.apache.commons.lang.Validate;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Map;
import java.util.logging.Logger;

public class AddOnClassLoader extends URLClassLoader {

    private final BasicAddOn addOn;
    private final AddOnProperties properties;
    private final SharedClassContext classContext;
    private final Map<String, Class<?>> classes = Maps.newHashMap();
    private final File dataFolder;
    private final File file;
    private I18N i18N;
    private final AddOnManager manager;

    public AddOnClassLoader(File file, ClassLoader parent, AddOnProperties properties, AddOnManager manager,
            SharedClassContext ctx, File dataFolder) throws InvalidAddOnException, MalformedURLException {
        super(new URL[] { file.toURI().toURL() }, parent);

        this.file = file;
        this.dataFolder = dataFolder;
        this.properties = properties;
        this.classContext = ctx;
        this.manager = manager;

        String mainClassName = properties.getMainClass();
        Class<?> mainClass;

        try {
            mainClass = Class.forName(mainClassName, true, this);
        } catch (ClassNotFoundException e) {
            throw new InvalidAddOnException("Cannot find main class \"" + mainClassName + "\"", e);
        }

        Class<? extends BasicAddOn> addOnClass;

        try {
            addOnClass = mainClass.asSubclass(BasicAddOn.class);
        } catch (ClassCastException e) {
            throw new InvalidAddOnException("Main class \"" + mainClassName + "\" does not extend AddOn", e);
        }

        try {
            addOn = addOnClass.newInstance();
        } catch (IllegalAccessException e) {
            throw new InvalidAddOnException(
                    "Main class \"" + mainClassName + "\" does not declare an public empty constructor", e);
        } catch (InstantiationException e) {
            throw new InvalidAddOnException("Main class \"" + mainClassName + "\" could not be instantiated", e);
        }
    }

    public BasicAddOn getAddOn() {
        return addOn;
    }

    public void setI18N(I18N i18n) {
        i18N = i18n;
    }

    @Override
    protected Class<?> findClass(String name) throws ClassNotFoundException {
        return findClass(name, true);
    }

    Class<?> findClass(String name, boolean checkGlobal) throws ClassNotFoundException {
        Validate.notNull(name, "Name cannot be null");

        Class<?> clazz = classes.get(name);

        if (clazz == null) {
            if (checkGlobal) {
                //Get global class
                classContext.getGlobalClass(name);
            }

            if (clazz == null) {
                clazz = super.findClass(name);

                if (clazz != null) {
                    //Register the class in the global class context
                    classContext.registerClass(addOn, clazz);
                    classes.put(name, clazz);
                }
            }
        }

        return clazz;
    }

    void initialize(HeavySpleef heavySpleef, Logger logger) {
        addOn.init(heavySpleef, dataFolder, properties, file, this, manager, i18N, logger);
    }

}