com.webapp.config.DataBaseConfig.java Source code

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Here is the source code for com.webapp.config.DataBaseConfig.java

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/*
 * Copyright (c) 2014 Stephan D. Cote' - All rights reserved.
 * 
 * This program and the accompanying materials are made available under the 
 * terms of the MIT License which accompanies this distribution, and is 
 * available at http://creativecommons.org/licenses/MIT/
 *
 * Contributors:
 *   Stephan D. Cote 
 *      - Initial concept and initial implementation
 */
package com.webapp.config;

import java.sql.Driver;

import javax.annotation.Resource;
import javax.sql.DataSource;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.jdbc.datasource.SimpleDriverDataSource;

import com.webapp.dao.DefaultDataStore;
import com.webapp.dao.WebAppDataStore;

/**
 * Most web applications need some type of data store.
 * 
 * <p>This is an example of setting up a DataSource for the application.</p>
 * 
 * <p>This code goes one better and sets up an application-specific DAO. This 
 * is an example of course, but it can be extended to meet the needs of almost 
 * any quick-start application.</p>
 */
@Configuration
public class DataBaseConfig {
    private static final Log LOG = LogFactory.getLog(DataBaseConfig.class);

    static final String PROPERTY_NAME_DATABASE_DRIVER = "db.driver";
    static final String PROPERTY_NAME_DATABASE_URL = "db.url";
    static final String PROPERTY_NAME_DATABASE_USERNAME = "db.username";
    static final String PROPERTY_NAME_DATABASE_PASSWORD = "db.password";

    @Resource
    private Environment env;

    /**
     * This creates a generic datasource for the web application.
     * 
     * <p>It uses system properties to determine the configuration.</p>
     * 
     * @return A datasource 
     */
    @Bean
    public DataSource dataSource() {
        LOG.info("Creating a datasource..");
        SimpleDriverDataSource dataSource = new SimpleDriverDataSource();
        try {
            LOG.info("Classname: " + env.getRequiredProperty(PROPERTY_NAME_DATABASE_DRIVER));
            @SuppressWarnings("unchecked")
            Class<? extends Driver> driverClass = (Class<? extends Driver>) Class
                    .forName(env.getRequiredProperty(PROPERTY_NAME_DATABASE_DRIVER));
            dataSource.setDriverClass(driverClass);

            LOG.info("URL: " + env.getRequiredProperty(PROPERTY_NAME_DATABASE_URL));
            dataSource.setUrl(env.getRequiredProperty(PROPERTY_NAME_DATABASE_URL));

            LOG.info("User: " + env.getRequiredProperty(PROPERTY_NAME_DATABASE_USERNAME));
            dataSource.setUsername(env.getRequiredProperty(PROPERTY_NAME_DATABASE_USERNAME));

            dataSource.setPassword(env.getRequiredProperty(PROPERTY_NAME_DATABASE_PASSWORD));
            LOG.info("Datasource created successfully.");
        } catch (ClassNotFoundException | IllegalStateException e) {
            LOG.fatal("Could not create driver class '" + env.getRequiredProperty(PROPERTY_NAME_DATABASE_DRIVER)
                    + "'", e);
        }

        return dataSource;
    }

    /**
     * Create an application-specific Data Access Object (DAO).
     * 
     * @param source The datasource to use.
     * 
     * @return An initialized DAO.
     */
    @Bean
    public WebAppDataStore datastore(DataSource source) {
        WebAppDataStore retval = new DefaultDataStore(source);

        // Set properties

        // Initialize the data store
        try {
            retval.init();
        } catch (Exception e) {
            LOG.fatal("Could not initialize data store.", e);
        }

        return retval;
    }

}