com.comcast.cats.recorder.persistence.SqlTableCreator.java Source code

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Here is the source code for com.comcast.cats.recorder.persistence.SqlTableCreator.java

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/**
 * Copyright 2014 Comcast Cable Communications Management, LLC
 *
 * This file is part of CATS.
 *
 * CATS 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.
 *
 * CATS 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 CATS.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.comcast.cats.recorder.persistence;

import java.io.File;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;

/**
 * A simple utility to create schema based on Entity classes.
 * 
 */
public class SqlTableCreator {
    private AnnotationConfiguration cfg;

    public SqlTableCreator(String packageName) throws Exception {
        cfg = new AnnotationConfiguration();
        cfg.setProperty("hibernate.hbm2ddl.auto", "create");

        for (Class<Object> clazz : getClasses(packageName)) {
            cfg.addAnnotatedClass(clazz);
        }
    }

    /**
     * Method that actually creates the file.
     * 
     * @param dbDialect
     *            to use
     */
    private void generate(Dialect dialect) {
        cfg.setProperty("hibernate.dialect", dialect.getDialectClass());

        SchemaExport export = new SchemaExport(cfg);
        export.setDelimiter(";");
        export.setOutputFile("ddl_" + dialect.name().toLowerCase() + ".sql");
        export.execute(true, false, false, false);
    }

    /**
     * Utility method used to fetch Class list based on a package name.
     * 
     * @param packageName
     *            (should be the package containing your annotated beans.
     */
    @SuppressWarnings("rawtypes")
    private List<Class> getClasses(String packageName) throws Exception {
        List<Class> classes = new ArrayList<Class>();
        File directory = null;
        try {
            ClassLoader cld = Thread.currentThread().getContextClassLoader();
            if (cld == null) {
                throw new ClassNotFoundException("Can't get class loader.");
            }
            String path = packageName.replace('.', '/');
            URL resource = cld.getResource(path);
            if (resource == null) {
                throw new ClassNotFoundException("No resource for " + path);
            }
            directory = new File(resource.getFile());
        } catch (NullPointerException x) {
            throw new ClassNotFoundException(
                    packageName + "does not appear to be a valid package. " + x.getMessage());
        }
        if (directory.exists()) {
            String[] files = directory.list();
            for (int i = 0; i < files.length; i++) {
                if (files[i].endsWith(".class")) {
                    // removes the .class extension
                    classes.add(Class.forName(packageName + '.' + files[i].substring(0, files[i].length() - 6)));
                }
            }
        } else {
            throw new ClassNotFoundException(packageName + " is not a valid package");
        }

        return classes;
    }

    /**
     * Holds the classnames of hibernate dialects for easy reference.
     */
    private static enum Dialect {
        ORACLE("org.hibernate.dialect.Oracle10gDialect"), MYSQL("org.hibernate.dialect.MySQLDialect"), HSQL(
                "org.hibernate.dialect.HSQLDialect");

        private String dialectClass;

        private Dialect(String dialectClass) {
            this.dialectClass = dialectClass;
        }

        public String getDialectClass() {
            return dialectClass;
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {
        SqlTableCreator gen = new SqlTableCreator("com.comcast.cats.reorder.persistence.domain");
        gen.generate(Dialect.MYSQL);
        gen.generate(Dialect.ORACLE);
        gen.generate(Dialect.HSQL);
    }

}