JPAConfiguration.java

package travel.snapshot.dp.ota.configuration;

import org.apache.commons.dbcp2.ConnectionFactory;
import org.apache.commons.dbcp2.DriverManagerConnectionFactory;
import org.apache.commons.dbcp2.PoolableConnection;
import org.apache.commons.dbcp2.PoolableConnectionFactory;
import org.apache.commons.dbcp2.PoolingDataSource;
import org.apache.commons.pool2.ObjectPool;
import org.apache.commons.pool2.impl.GenericObjectPool;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
import org.hibernate.jpa.HibernatePersistenceProvider;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.PropertiesLoaderUtils;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import java.io.IOException;
import java.sql.SQLException;
import java.util.Properties;

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

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = "travel.snapshot.dp.ota.db.dal")
public class JPAConfiguration {

    private static final String PROPERTY_NAME_DATABASE_DRIVER = "db.driver";
    private static final String PROPERTY_NAME_DATABASE_PASSWORD = "db.password";
    private static final String PROPERTY_NAME_DATABASE_URL = "db.url";
    private static final String PROPERTY_NAME_DATABASE_USERNAME = "db.username";
    private static final String PROPERTY_NAME_DB_POOL_MAX_TOTAL = "db.pool.max_total";
    private static final String PROPERTY_NAME_DB_POOL_MAX_IDLE = "db.pool.max_idle";
    private static final String PROPERTY_NAME_DB_POOL_MIN_IDLE = "db.pool.min_idle";
    private static final String PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN = "entitymanager.packages.to.scan";

    @Resource(name = "dbProperties")
    private Properties dbProperties;
    

    @Bean
    public Properties dbProperties() throws IOException {
        return PropertiesLoaderUtils.loadProperties(new ClassPathResource("/db.properties"));
    }

    @Bean
    public DataSource otaDataSource() throws ClassNotFoundException {
        Class.forName(dbProperties.getProperty(PROPERTY_NAME_DATABASE_DRIVER));
        Properties dbConProperties = new Properties();
        dbConProperties.put("user", dbProperties.getProperty(PROPERTY_NAME_DATABASE_USERNAME));
        dbConProperties.put("password", dbProperties.getProperty(PROPERTY_NAME_DATABASE_PASSWORD));
        ConnectionFactory connectionFactory = new DriverManagerConnectionFactory(
                dbProperties.getProperty(PROPERTY_NAME_DATABASE_URL), dbConProperties);
        PoolableConnectionFactory poolableConnectionFactory =
                new PoolableConnectionFactory(connectionFactory, null);
        GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig();
        poolConfig.setMaxTotal(Integer.parseInt(dbProperties.getProperty(PROPERTY_NAME_DB_POOL_MAX_TOTAL)));
        poolConfig.setMaxIdle(Integer.parseInt(dbProperties.getProperty(PROPERTY_NAME_DB_POOL_MAX_IDLE)));
        poolConfig.setMinIdle(Integer.parseInt(dbProperties.getProperty(PROPERTY_NAME_DB_POOL_MIN_IDLE)));
        poolConfig.setTestOnBorrow(true);
        ObjectPool<PoolableConnection> connectionPool =
                new GenericObjectPool<>(poolableConnectionFactory, poolConfig);
        poolableConnectionFactory.setPool(connectionPool);
        return new PoolingDataSource<>(connectionPool);
    }

    @Bean
    public JpaTransactionManager transactionManager() {
        return new JpaTransactionManager();
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(DataSource otaDataSource) throws ClassNotFoundException, SQLException {
        LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();

        entityManagerFactoryBean.setDataSource(otaDataSource);
        entityManagerFactoryBean.setPersistenceProviderClass(HibernatePersistenceProvider.class);
        entityManagerFactoryBean
                .setPackagesToScan(dbProperties.getProperty(PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN));
        entityManagerFactoryBean.setJpaProperties(dbProperties);

        return entityManagerFactoryBean;
    }
}