package cn.myapps.base.dao;

/**
 * The data source pooling.
 */
import java.sql.Connection;

import javax.sql.DataSource;

import org.apache.commons.dbcp.cpdsadapter.DriverAdapterCPDS;
import org.apache.commons.dbcp.datasources.PerUserPoolDataSource;

import cn.myapps.util.property.DefaultProperty;

public class PoolingDataSource {
	
	private static DataSource datasource = null;
	
	private static String _DRIVER = "DB_DRIVER";

	private static String _URL = "DB_URL";

	private static String _USER = "DB_USER";

	private static String _PASSWORD = "DB_PASSWORD";

	private static String _MAXACTIVE = "DB_MAXACTIVE";

	private static String _MAXWAIT = "DB_MAXWAIT";	

	/**
	 * Get the data source.
	 * @return 
	 * @throws Exception
	 */
	public static DataSource getDataSource() throws Exception {	
		if (datasource == null) {
			datasource = createPerUserPoolDatasource();			
		}		
		return datasource;
	}
	
	/**
	 * Crate the per-user-pool datasource.
	 * @return The per-user-pool datasource.
	 * @throws Exception
	 */
	private static DataSource createPerUserPoolDatasource() throws Exception{
		DriverAdapterCPDS pcds;
		pcds = new DriverAdapterCPDS();
		pcds.setDriver(DefaultProperty.getProperty(_DRIVER));

		pcds.setUrl(DefaultProperty.getProperty(_URL));
		pcds.setUser(DefaultProperty.getProperty(_USER));
		pcds.setPassword(DefaultProperty.getProperty(_PASSWORD));
		pcds.setPoolPreparedStatements(false);

		PerUserPoolDataSource tds = new PerUserPoolDataSource();
		tds.setConnectionPoolDataSource(pcds);
		tds.setDefaultMaxActive(Integer.parseInt(DefaultProperty
				.getProperty(_MAXACTIVE)));
		tds.setDefaultMaxWait(Integer.parseInt(DefaultProperty
				.getProperty(_MAXWAIT)));
		tds
				.setDefaultTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);

		return tds;
	}

}