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package vn.mobileid.jackrabbit.uat.db;


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.concurrent.locks.ReentrantLock;

import org.apache.log4j.Logger;


/**
 *
 * @author cuongdvh
 */
public class DatabaseConnection {
	
	
    final static Logger logger = Logger.getLogger(DatabaseConnection.class);
    
    private static DatabaseConnection instance = null;
    private static ReentrantLock lock = new ReentrantLock();
    
	private static String URL_CFG;
	private static String USERNAME_CFG;
	private static String PASSWORD_CFG;
	
	//public static AtomicInteger cntConnections = new AtomicInteger(0);
	//public static AtomicInteger openConFail = new AtomicInteger(0);
	
	//public static int max = 0;
	
	public static void setURL_CFG(String uRL_CFG) {
		URL_CFG = uRL_CFG;
	}

	public static void setUSERNAME_CFG(String uSERNAME_CFG) {
		USERNAME_CFG = uSERNAME_CFG;
	}

	public static void setPASSWORD_CFG(String pASSWORD_CFG) {
		PASSWORD_CFG = pASSWORD_CFG;
	}
	
	private String url;
	private String userName;
	private String password;
       
    public DatabaseConnection(String url, String userName, String password) throws InstantiationException, IllegalAccessException, ClassNotFoundException{
    	this.url = url + "?useUnicode=true&characterEncoding=utf-8&autoReconnect=true&useSSL=false";
    	this.userName = userName;
    	this.password = password;
    	Class.forName("com.mysql.cj.jdbc.Driver").newInstance();    	
    }    
    
    public static DatabaseConnection getInstance()  {
		if(instance != null)
			return instance;
		
		lock.lock();
		if(instance != null){
			lock.unlock();
			return instance;
		}
		
		try {
			instance = new DatabaseConnection(URL_CFG, USERNAME_CFG, PASSWORD_CFG);
		} catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		lock.unlock();
		
		return instance;
	}
    
    public Connection createConnection() throws SQLException {
    	/*int counter = cntConnections.incrementAndGet();
    	logger.info("Create connection " + counter);
    	
    	lock.lock();
		if(max < counter){
			max = counter;
			logger.info("*************Max DB connections: " + max);
		}
		lock.unlock();*/
		
		try{
			return DriverManager.getConnection(url, userName, password);
		} catch (SQLException e) {
			// TODO: handle exception
			e.printStackTrace();
			//openConFail.incrementAndGet();
			throw e;			
		}        
    }
    
    public int releaseConnection(Connection conn) throws SQLException{
    	if(conn != null)
    		conn.close();    	
    	return 0;
    	
    	/*int cons = cntConnections.decrementAndGet();
    	
    	logger.info("Release connection " + cons);
    	return cons;*/
    }
}