PrintSchemaUpdate.java

package drivers;

import java.io.File;
import java.sql.SQLException;
import java.util.List;

import javax.persistence.Entity;

import org.hibernate.dialect.Dialect;
import org.hibernate.ejb.Ejb3Configuration;
import org.hibernate.tool.hbm2ddl.DatabaseMetadata;

import play.Play;
import play.db.DB;
import play.db.DBPlugin;

/**
 * Creates Schema updates
 * 
 * 
 * @author Gonto
 * @since Dec 4, 2012
 */
public final class PrintSchemaUpdate {

    /**
     * Creates the PrintSchemaUpdate.
     */
    private PrintSchemaUpdate() {

    }

    /**
     * Generates Schema Update SQL script
     * 
     * @param args
     * @throws SQLException
     * @throws Exception
     */
    public static void main(final String[] args) throws Exception {
        String id = "schema";
        if (args.length > 0) {
            id = args[0];
        }

        // Starting up Play!
        Play.init(new File("."), id);

        // Getting DB configuration from Play!'s application configuration
        final String db = Play.configuration.getProperty("db");
        final String dialect = Play.configuration.getProperty("jpa.dialect");
        final String ddl = Play.configuration.getProperty("jpa.ddl");
        System.out.println("Connection against " + db);

        // Setting hibernate configuration
        final Ejb3Configuration configuration = new Ejb3Configuration();
        configuration.setProperty("hibernate.dialect", dialect);
        configuration.setProperty("hibernate.ddl", ddl);
        configuration.setProperty("hibernate.db", db);

        // Getting persisten classes
        final List<Class> classes = Play.classloader.getAnnotatedClasses(Entity.class);
        for (final Class clazz : classes) {
            configuration.addAnnotatedClass(clazz);
        }
        configuration.buildEntityManagerFactory();
        final DBPlugin plugin = new DBPlugin();
        plugin.onApplicationStart();
        Dialect dialectInstance = (Dialect) Class.forName(dialect).newInstance();
        final DatabaseMetadata metadata = new DatabaseMetadata(DB.getConnection(), dialectInstance);
        final String[] sa = configuration.getHibernateConfiguration().generateSchemaUpdateScript(
                dialectInstance, metadata);

        System.out.println("Schema update scripts:");
        for (final String s : sa) {
            System.out.println(s + ";");
        }
        System.exit(0);
    }

}