커넥션 풀 connection pool

의존성 

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-dbcp2</artifactId>
    <version>2.4.0</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
    <version>2.5.0</version>
</dependency>
<dependency>
    <groupId>commons-logging</groupId>
    <artifactId>commons-logging</artifactId>
    <version>1.2</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.48</version>
</dependency>

 

커넥션 풀 설정 : DBCPinit

package jdbc;

import org.apache.commons.dbcp2.*;
import org.apache.commons.pool2.impl.GenericObjectPool;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBCPInit extends HttpServlet {

    @Override
    public void init() throws ServletException {
        System.out.println("잘되니?");
        loadJDBCDriver();
        initConnectionPool();
    }

    private void loadJDBCDriver()  {
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            throw new RuntimeException("fail to load jdbc Driver",e);
        }
    }

    private void initConnectionPool() {
        String url = "jdbc:mysql://localhost:3306/guestbook?characterEncoding=UTF-8&useSSL=false";
        String uid = "root";
        String upw = "1234";

        ConnectionFactory connectionFactory = new DriverManagerConnectionFactory(url,uid,upw);
        PoolableConnectionFactory poolableConnectionFactory =
                new PoolableConnectionFactory(connectionFactory,null);
        poolableConnectionFactory.setValidationQuery("select 1");

        GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig();
        poolConfig.setTestWhileIdle(true);
        poolConfig.setMinIdle(4);
        poolConfig.setMaxTotal(50);

        GenericObjectPool<PoolableConnection> connectionPool =
                new GenericObjectPool<>(poolableConnectionFactory,poolConfig);

        try {
            Class.forName("org.apache.commons.dbcp2.PoolingDriver");
            PoolingDriver driver = (PoolingDriver) DriverManager.getDriver("jdbc:apache:commons:dbcp:");
            driver.registerPool("guestbook",connectionPool);
        } catch (ClassNotFoundException | SQLException e) {
            throw new RuntimeException(e);
        }
    }
}

web.xml

<servlet>
    <servlet-name>dbcpInit</servlet-name>
    <servlet-class>jdbc.DBCPInit</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

 

 

커넥션풀 사용 : ConnectionProvider

package jdbc;

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

public class ConnectionProvider {

    public static Connection getConnection() throws SQLException {
        String url = "jdbc:apache:commons:dbcp:guestbook";
        return DriverManager.getConnection(url);
    }
}