uk.co.modularaudio.util.hibernate.generator.GeneratorHelper.java Source code

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Here is the source code for uk.co.modularaudio.util.hibernate.generator.GeneratorHelper.java

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/**
 *
 * Copyright (C) 2015 - Daniel Hams, Modular Audio Limited
 *                      daniel.hams@gmail.com
 *
 * Mad 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.
 *
 * Mad 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 Mad.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package uk.co.modularaudio.util.hibernate.generator;

import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.springframework.context.support.GenericApplicationContext;

import uk.co.modularaudio.util.exception.DatastoreException;
import uk.co.modularaudio.util.hibernate.component.ComponentWithHibernatePersistence;
import uk.co.modularaudio.util.hibernate.component.HibernatePersistedBeanDefinition;
import uk.co.modularaudio.util.hibernate.component.TableNamePrefixer;
import uk.co.modularaudio.util.io.IOUtils;
import uk.co.modularaudio.util.spring.SpringComponentHelper;

public class GeneratorHelper {
    /**
     * Generate the DDL for one component implementing the IsHibernatePersistedComponent interface
     * @param component The persisted component we wish to obtain the DDL for
     * @param dialectName Which hibernate dialect should be used
     * @param destinationDirectory The output directory
     * @param outputFileName The output filename
     * @throws IOException On errors reading the related hbm files for a component or writing the output DDL file
     */
    public void generateDDL(final ComponentWithHibernatePersistence component, final String dialectName,
            final String destinationDirectory, final String outputFileName) throws IOException {
        final Configuration configuration = new Configuration();
        final List<HibernatePersistedBeanDefinition> listHBM = component.listHibernatePersistedBeanDefinitions();
        for (final HibernatePersistedBeanDefinition hbmDefinition : listHBM) {
            final String originalHbmResourceName = hbmDefinition.getHbmResourceName();

            final InputStream hbmInputStream = Thread.currentThread().getContextClassLoader()
                    .getResourceAsStream(originalHbmResourceName);

            final String originalHbmString = IOUtils.basicReadInputStreamUTF8(hbmInputStream);

            final String newHbmString = TableNamePrefixer.prefixTableNames(originalHbmString,
                    hbmDefinition.getPersistedBeanTablePrefix());

            configuration.addXML(newHbmString);

        }
        configureAndGenerate(dialectName, destinationDirectory, outputFileName, configuration);
    }

    /**
     * Method to configure necessary hibernate properties and generate DDL for a supplied configuration
     * @param dialectName Which hibernate dialect should be used
     * @param destinationDirectory The output directory
     * @param outputFileName The output filename
     * @param configuration The hibernate configuration setup with the appropriate schema objects
     */
    private void configureAndGenerate(final String dialectName, final String destinationDirectory,
            final String outputFileName, final Configuration configuration) {
        final Properties dialect = new Properties();
        dialect.setProperty("hibernate.dialect", dialectName);
        configuration.addProperties(dialect);

        final SchemaExport se = new SchemaExport(configuration);
        se.setOutputFile(destinationDirectory + outputFileName);
        se.setDelimiter(";\n");
        se.create(true, false);
    }

    /**
     * Generate an appropriate DDL by loading a Spring beans.xml and searching for components implementing the IsHibernatePersistedComponent interface
     * @param beansFilename The Spring beans.xml file to read
     * @param configurationFilename The configuration filename necessary
     * @param dialectName The hibernate dialect that should be used
     * @param destinationDirectory The output directory
     * @param outputFileName The output filename
     * @throws DatastoreException A general failure during processing (such as starting up the application context)
     * @throws IOException On errors setting up the components, reading the HBM configurations or writing the output DDL file
     */
    public void generateFromBeansDDL(final String beansFilename, final String configurationFilename,
            final String dialectName, final String destinationDirectory, final String outputFileName)
            throws DatastoreException, IOException {
        final Configuration configuration = new Configuration();
        final SpringComponentHelper sch = new SpringComponentHelper();
        final GenericApplicationContext appContext = sch.makeAppContext(beansFilename, configurationFilename);

        final Map<String, ComponentWithHibernatePersistence> components = appContext
                .getBeansOfType(ComponentWithHibernatePersistence.class);

        for (final Iterator<ComponentWithHibernatePersistence> iter = components.values().iterator(); iter
                .hasNext();) {
            final ComponentWithHibernatePersistence component = iter.next();
            final List<HibernatePersistedBeanDefinition> hbmDefinitions = component
                    .listHibernatePersistedBeanDefinitions();

            for (final HibernatePersistedBeanDefinition beanDefinition : hbmDefinitions) {
                final String originalHbmResourceName = beanDefinition.getHbmResourceName();

                final InputStream hbmInputStream = Thread.currentThread().getContextClassLoader()
                        .getResourceAsStream(originalHbmResourceName);

                final String originalHbmString = IOUtils.basicReadInputStreamUTF8(hbmInputStream);

                final String newHbmString = TableNamePrefixer.prefixTableNames(originalHbmString,
                        beanDefinition.getPersistedBeanTablePrefix());

                configuration.addXML(newHbmString);
            }
        }
        configureAndGenerate(dialectName, destinationDirectory, outputFileName, configuration);
        appContext.close();
    }
}