AbstractPluginControllerFactory.java

/*
 * Copyright 2005-2015 by BerryWorks Software, LLC. All rights reserved.
 *
 * This file is part of EDIReader. You may obtain a license for its use directly from
 * BerryWorks Software, and you may also choose to use this software under the terms of the
 * GPL version 3. Other products in the EDIReader software suite are available only by licensing
 * with BerryWorks. Only those files bearing the GPL statement below are available under the GPL.
 *
 * EDIReader 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.
 *
 * EDIReader 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 EDIReader.  If not,
 * see <http://www.gnu.org/licenses/>.
 */

package com.berryworks.edireader.plugin;

import com.berryworks.edireader.EDIAbstractReader;
import com.berryworks.edireader.Plugin;
import com.berryworks.edireader.PluginController;
import com.berryworks.edireader.tokenizer.Tokenizer;

import java.util.HashMap;
import java.util.Map;

import static com.berryworks.edireader.util.FixedLength.isPresent;

public abstract class AbstractPluginControllerFactory implements PluginControllerFactoryInterface {

    protected static final Map<String, Plugin> pluginCache = new HashMap<>();
    protected static boolean debug;

    protected String lastPluginLoaded = null;
    protected PluginController lastPluginController;

    public String getLastPluginLoaded() {
        return lastPluginLoaded;
    }

    /**
     * Creates a new instance of a PluginController, selecting a plugin based on the standard and type of document.
     *
     * @param standard  - name of EDI standard (for example: "EDIFACT" or "ANSI")
     * @param docType   - type of document (for example: "837" or "INVOIC")
     * @param tokenizer - reference to the Tokenizer to provide context for syntax exceptions
     * @return instance of a PluginController
     */
    @Override
    public PluginController create(String standard, String docType, Tokenizer tokenizer) {
        return create(standard, docType, null, null, tokenizer);
    }


    /**
     * Find a plugin for a given standard, document type, version, and release.
     * If no matching plugin is found, return null.
     * Plugins are cached so that once a plugin is loaded it can be quickly found again without using the
     * class loader.
     *
     * @param standard   - name of EDI standard (for example: "EDIFACT" or "ANSI")
     * @param docType    - type of document (for example: "837" or "INVOIC")
     * @param docVersion - a particular version of the standard (for example: "X" in ANSI or "04A" in EDIFACT)
     * @param docRelease - a particular release of the standard (for example: "D" in EDIFACT or "004010" in ANSI)
     * @return Plugin that was found, or null if no suitable plugin was found
     */
    protected Plugin loadPlugin(String standard, String docType, String docVersion, String docRelease) {
        Plugin result = null;
        String key = standard + "_" + docType + "_" + docVersion + "_" + docRelease;
        if (pluginCache.containsKey(key)) {
            if (debug)
                trace("plugin for " + key + " found in cache");
            lastPluginLoaded = key;
            result = pluginCache.get(key);

        } else {
            String suffix = System.getProperty("EDIREADER_PLUGIN_SUFFIX");
            if (isPresent(docVersion) && isPresent(docRelease)) {
                if (isPresent(suffix))
                    result = lookForSpecificPlugin(standard, docVersion + "_" + docRelease + "." + standard + "_" + docType + "_" + suffix);

                if (result == null)
                    result = lookForSpecificPlugin(standard, docVersion + "_" + docRelease + "." + standard + "_" + docType);

                if (isPresent(suffix))
                    result = lookForSpecificPlugin(standard, docType + "_" + docVersion + "_" + docRelease + "_" + suffix);

                if (result == null)
                    result = lookForSpecificPlugin(standard, docType + "_" + docVersion + "_" + docRelease);
            }
            if (result == null && isPresent(suffix))
                result = lookForSpecificPlugin(standard, docType + "_" + suffix);

            if (result == null)
                result = lookForSpecificPlugin(standard, docType);

            if (result != null)
                pluginCache.put(key, result);
        }

        return result;
    }

    /**
     * Shorthand for EDIReader.trace(String)
     *
     * @param text message to appear in trace
     */
    protected static void trace(String text) {
        EDIAbstractReader.trace(text);
    }

    @Override
    public PluginController getLastControllerCreated() {
        return lastPluginController;
    }

    public void clearCache() {
        pluginCache.clear();
    }

    /**
     * Creates a new instance of a PluginController, selecting a plugin based on the standard, the type of document,
     * and the version and release characteristics.
     * <p>
     * This factory method supports version-specific plugins for a given type of document. If first tries to load
     * a plugin specific to a particular release and version using the naming convention for plugin class names.
     * If no version-specific plugin is available, it uses the other factory method
     * to create a plugin based simply on the standard and type.
     *
     * @param standard   - name of EDI standard (for example: "EDIFACT" or "ANSI")
     * @param docType    - type of document (for example: "837" or "INVOIC")
     * @param docVersion - a particular version of the standard (for example: "X" in ANSI or "04A" in EDIFACT)
     * @param docRelease - a particular release of the standard (for example: "D" in EDIFACT or "004010" in ANSI)
     * @param tokenizer  - reference to the Tokenizer to provide context for syntax exceptions
     * @return instance of a PluginController
     */
    @Override
    public PluginController create(String standard, String docType, String docVersion, String docRelease, Tokenizer tokenizer) {
        PluginControllerImpl result;
        Plugin plugin = loadPlugin(standard, docType, docVersion, docRelease);

        if (plugin == null) {
            result = new PluginControllerImpl(standard, tokenizer);
            result.setEnabled(false);
        } else {
            plugin.init();
            result = plugin.createController(standard, tokenizer);
            result.setEnabled(true);
        }

        result.setDocumentType(docType);
        result.setPlugin(plugin);
        lastPluginController = result;
        return result;
    }

    protected abstract Plugin lookForSpecificPlugin(String standard, String docType);

    protected abstract Plugin getInstance(String standard, String docType) throws Exception;

}