java/Db Connection

Default :

public class BlogManager {
    private Connection conn;
    private static Logger logger = Logger.getLogger(BlogManager.class);

    public BlogManager(){
        try {
            //Class.forName("com.mysql.jdbc.Driver").newInstance();
            //conn = DriverManager.getConnection("jdbc:mysql://localhost/setzer?user=setzer&password=PASSWORD&useUnicode=true&characterEncoding=utf8");
            Class.forName("org.postgresql.Driver").newInstance();
            conn = DriverManager.getConnection("jdbc:postgresql://localhost/setzer","setzer","PASSWORD");
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException ex) {
            logger.error("SQLException: " + ex.getMessage());
            logger.error("SQLState: " + ex.getSQLState());
            logger.error("VendorError: " + ex.getErrorCode());
        }
    }
}

Using DataSource in Struts
[http]

Datasource Example without Struts
[http]

Accessing a Database(Struts Guide)

Tomcat JNDI DataSource
[http]

참고

일반적인 연결 ¶

/*
 * Created on 2005. 4. 3
 */
package net.db;

import java.sql.Connection;
import java.sql.SQLException;

import javax.sql.DataSource;

import org.apache.commons.dbcp.BasicDataSource;
import org.apache.log4j.Logger;


/**
 * @author setzer
 */
public class ConnectionFactory {
    private static DataSource datasource = null;
    private static Logger logger = Logger.getLogger(ConnectionFactory.class);

    private ConnectionFactory(){
        //ignore
    }

    public static Connection getConnection() throws SQLException{
        if(datasource == null){
            datasource = getDataSource("jdbc:postgresql://localhost/setzer");
        }

        return datasource.getConnection();
    }

    private static DataSource getDataSource(String connectURI){
        BasicDataSource ds = new BasicDataSource();
        ds.setDriverClassName("org.postgresql.Driver");
        ds.setUsername("setzer");
        ds.setPassword("PASSWORD");
        ds.setUrl(connectURI);
        return ds;
    }

    private static void shutdownDataSource(DataSource ds) throws SQLException{
        BasicDataSource bds = (BasicDataSource) ds;
        bds.close();
    }

}

리소스 번들을 이용 ¶

/*
 * Created on 2005. 4. 3
 */
package net.db;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.sql.DataSource;

import org.apache.commons.dbcp.BasicDataSource;
import org.apache.log4j.Logger;

/**
 * @author setzer
 */
public class ConnectionFactory extends HttpServlet{
    private static DataSource datasource = null;
    private static Logger logger = Logger.getLogger(ConnectionFactory.class);
    private static ConnectionFactory instance = null;
    private static Properties props = null;

    public ConnectionFactory(){
        /*
        try{
            this.init();
        }catch(ServletException e){
            logger.error(e);
        }
        */
    }

    public void init() throws ServletException{
        props = new Properties();
        try{
	        InputStream in = getServletContext().getResourceAsStream("/WEB-INF/db.properties");
	        props.load(in);
	        in.close();

	        setDataSource(props);
        }catch(IOException e){
            throw new ServletException(e);
        }
        instance = this;
    }

    public void destroy(){
        try{
            shutdownDataSource();
        }catch(SQLException e){
            logger.error(e);
        }
    }

    public static ConnectionFactory getInstance(){
        if(instance == null){
            instance = new ConnectionFactory();
        }
        return instance;
    }

    public static Connection getConnection() throws SQLException{
        if(datasource == null){
            throw new SQLException();
        }
        return datasource.getConnection();
    }

    private static void setDataSource(Properties props) throws IOException{
        BasicDataSource ds = new BasicDataSource();
        //almost, default value is 8
        //logger.error(new Integer(ds.getMaxActive()));
        ds.setMaxActive(Integer.parseInt(props.getProperty("connection.maxActive")));
        ds.setDriverClassName(props.getProperty("connection.driver"));
        ds.setUsername(props.getProperty("user"));
        ds.setPassword(props.getProperty("password"));
        ds.setUrl(props.getProperty("connection.url"));
        datasource = ds;
    }

    private static void shutdownDataSource() throws SQLException{
        BasicDataSource bds = (BasicDataSource) datasource;
        bds.close();
    }

}

db.properties :

 connection.maxActive=0
connection.driver=org.postgresql.Driver
connection.url=jdbc:postgresql://localhost/setzer
user=setzer
password=PASSWORD

득중유고

java/Db Connection

java/Db Connection

일반적인 연결 ¶

리소스 번들을 이용 ¶