EDIT

/**

 * Copyright (C) 2015 EDIT

 * European Distributed Institute of Taxonomy

 * http://www.e-taxonomy.eu

 *

 * The contents of this file are subject to the Mozilla Public License Version 1.1

 * See LICENSE.TXT at the top of this package for the full license terms.

 */

package eu.etaxonomy.cdm.cache;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.lang.reflect.Field;

import java.net.URISyntaxException;

import java.net.URL;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import org.apache.logging.log4j.LogManager;

import org.apache.logging.log4j.Logger;

import org.hibernate.SessionFactory;

import org.hibernate.boot.Metadata;

import org.hibernate.boot.MetadataSources;

import org.hibernate.boot.registry.StandardServiceRegistry;

import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

import org.hibernate.cfg.Configuration;

import org.hibernate.mapping.PersistentClass;

import org.hibernate.mapping.Property;

import org.hibernate.metadata.ClassMetadata;

import org.hibernate.property.access.spi.Getter;

import net.sf.ehcache.Cache;

import net.sf.ehcache.Element;

/**

 * This class is serializing and deserializing the CDM model for performance purposes.

 * To serialize see comments on {@link #main(String[])} and on

 * https://dev.e-taxonomy.eu/redmine/projects/edit/wiki/TaxonomicEditorDevelopersGuide#Model-Change-Actions

 *

 * @author c.mathew

 * @since 2015

 */

public class CdmModelCacher {

    private static final Logger logger = LogManager.getLogger(CdmModelCacher.class);

    public static String HB_CONFIG_FILE_PATH= "/eu/etaxonomy/cdm/mappings/hibernate.cfg.xml";

    public static final String CDM_MAP_SER_FILE = "cdm.map.ser";

    public static final String CDM_MAP_SER_FOLDER = "/eu/etaxonomy/cdm/mappings/";

    public static final String CDM_MAP_SER_FILE_PATH = CDM_MAP_SER_FOLDER + CDM_MAP_SER_FILE;

    public void cacheGetterFields(Cache cache) throws IOException, ClassNotFoundException, URISyntaxException {

        Map<String, CdmModelFieldPropertyFromClass> modelClassMap = loadModelClassMap();

        cache.removeAll();

        for(Map.Entry<String, CdmModelFieldPropertyFromClass> entry : modelClassMap.entrySet()) {

            cache.put(new Element(entry.getKey(), entry.getValue()));

        }

    }

    public Map<String, CdmModelFieldPropertyFromClass> loadModelClassMap() throws URISyntaxException, IOException, ClassNotFoundException  {

        // ============== Eclpipse specific ============== //

        /*Bundle bundle = Platform.getBundle("eu.etaxonomy.taxeditor.cdmlib");

        URL modelMapFileBundleURL = bundle.getEntry(CDM_MAP_SER_FILE_PATH);

        URL modelMapFileURL = FileLocator.resolve(modelMapFileBundleURL);

        String modelMapFilePath = modelMapFileURL.getFile();

        FileInputStream fin = new FileInputStream(modelMapFilePath);

        */

        InputStream fin = this.getClass().getResourceAsStream(CDM_MAP_SER_FILE_PATH);

        // ==============000000000000000 ============== //

        ObjectInputStream ois = new ObjectInputStream(fin);

        @SuppressWarnings("unchecked")

		Map<String, CdmModelFieldPropertyFromClass> modelClassMap = (Map<String, CdmModelFieldPropertyFromClass>) ois.readObject();

        ois.close();

        return modelClassMap;

    }

    public Map<String, CdmModelFieldPropertyFromClass> generateModelClassMap() {

    	// A SessionFactory is set up once for an application!

        URL hibernateConfigFile = this.getClass().getResource(HB_CONFIG_FILE_PATH);

    	final StandardServiceRegistry registry = new StandardServiceRegistryBuilder()

    			.configure(hibernateConfigFile) // configures settings from hibernate.cfg.xml

    			.build();

    	SessionFactory sessionFactory = null;

    	Map<String, CdmModelFieldPropertyFromClass> modelClassMap = new HashMap<>();

    	try {

//    		ConnectionProvider connectionProvider = registry.getService(ConnectionProvider.class);

//    		DatasourceConnectionProviderImpl providerImpl = registry.getService(DatasourceConnectionProviderImpl.class);

    		Metadata metadata = new MetadataSources( registry ).buildMetadata();

    		sessionFactory = metadata.buildSessionFactory();

//    		Configuration configuration = buildConfiguration(HB_CONFIG_FILE_PATH);

        	Map<String, ClassMetadata> classMetaDataMap = sessionFactory.getAllClassMetadata();

//        	Metadata metadata = new MetadataSources( registry ).getMetadataBuilder().applyImplicitNamingStrategy( ImplicitNamingStrategyJpaCompliantImpl.INSTANCE ).build();

            for(ClassMetadata classMetaData : classMetaDataMap.values()) {

            	Class<?> mappedClass = classMetaData.getMappedClass();

                String mappedClassName = mappedClass.getName();

                PersistentClass persistentClass = metadata.getEntityBinding(mappedClassName);

                CdmModelFieldPropertyFromClass cmgmfc = new CdmModelFieldPropertyFromClass(mappedClassName);

                logger.warn("Adding class : " + mappedClassName + " to cache");

                addGetters(persistentClass, cmgmfc);

                modelClassMap.put(mappedClassName, cmgmfc);

            }

    	}

    	catch (Exception e) {

    		// The registry would be destroyed by the SessionFactory, but we had trouble building the SessionFactory

    		// so destroy it manually.

    		StandardServiceRegistryBuilder.destroy( registry );

    		e.printStackTrace();

    	}

        return modelClassMap;

    }

    public static Configuration buildConfiguration(String hibernateConfigFilePath) {

        Configuration configuration = new Configuration().configure(hibernateConfigFilePath);

        configuration.buildMappings();

        return configuration;

    }

    private void addGetters(PersistentClass persistentClass, CdmModelFieldPropertyFromClass cmgmfc) {

        if (persistentClass != null) {

            @SuppressWarnings("unchecked")

            Iterator<Property> propertyIt = persistentClass.getPropertyIterator();

            while(propertyIt.hasNext()){

                Property property = propertyIt.next();

                Getter getter = property.getGetter(persistentClass.getMappedClass());

                if(getter != null && getter.getMember() != null) {

                    Field field = (Field)getter.getMember();

                    //logger.info(" - contains field '" + field.getName() + "' of type '" + field.getType().getName() + "'");

                    cmgmfc.addGetMethods(field.getName());

                }

            }

            addGetters(persistentClass.getSuperclass(), cmgmfc);

        }

    }

    public static void main(String argv[]) {

        // To re-create the serialised cdm map run,

        // mvn exec:java -Dexec.mainClass="eu.etaxonomy.cdm.cache.CdmModelCacher"

        // in the eu.etaxonomy.taxeditor.cdmlib project root dir

    	// See also https://dev.e-taxonomy.eu/redmine/projects/edit/wiki/TaxonomicEditorDevelopersGuide#Model-Change-Actions

    	//Note AM: does not fully work for me, but running the main from the IDE works.

        CdmModelCacher cdmModelCacher = new CdmModelCacher();

        Map<String, CdmModelFieldPropertyFromClass> modelClassMap = cdmModelCacher.generateModelClassMap();

        try{

        	if (!modelClassMap.isEmpty()){

        	    File outFile = new File("src/main/resources/" + CDM_MAP_SER_FILE_PATH);

        	    System.out.println("writing to " + outFile.getAbsolutePath());

        		FileOutputStream fout = new FileOutputStream(outFile);

        		ObjectOutputStream oos = new ObjectOutputStream(fout);

        		oos.writeObject(modelClassMap);

        		oos.close();

        		System.out.println("CDM Map serialized");

        	}else{

        		String message = "CDM Map was empty. Model cache update NOT successful";

        		System.out.println(message);

        	}

        }catch(Exception ex){

            ex.printStackTrace();

        }

    }

}