Web 예제: SQLExecutor(익명 클래스) 와 TimeDAO (jsp로 시간 나오게 하기)

만드는 순서:

SQLExecutor

TimeDAO

TimeDAOTest

TimeService

AppListener

TimeController

time.jsp

package org.ph.dao;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

public abstract class SQLExecutor {

private static final String JDBC_APACHE_COMMONS_DBCP_POOL = "jdbc:apache:commons:dbcp:/pool";

private static final String ORG_APACHE_COMMONS_DBCP_POOLING_DRIVER = "org.apache.commons.dbcp.PoolingDriver";

private static final String ORACLE_JDBC_DRIVER_ORACLE_DRIVER = "oracle.jdbc.driver.OracleDriver";

protected Connection con;

protected PreparedStatement pstmt;

protected ResultSet rs;

public final void execute() throws Exception{

try {

makeConnection();

doJob();

} catch (Exception e) {

throw e;

}finally{

closeAll();

}

}

protected abstract void doJob();

private void makeConnection() throws Exception {

Class.forName(ORACLE_JDBC_DRIVER_ORACLE_DRIVER);

Class.forName(ORG_APACHE_COMMONS_DBCP_POOLING_DRIVER);

this.con = DriverManager.getConnection(JDBC_APACHE_COMMONS_DBCP_POOL);

}

private void closeAll() {

if(rs !=null){try{rs.close();}catch(Exception e){}}

if(pstmt !=null){try{rs.close();}catch(Exception e){}}

if(con !=null){try{rs.close();}catch(Exception e){}}

}

}

package org.ph.dao;

import java.sql.SQLException;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class TimeDAO {

private static Logger logger = LoggerFactory.getLogger("TimeDAO");

public String getTime() throws Exception{

final String sql = "select sysdate from dual";

final StringBuilder builder = new StringBuilder();

new SQLExecutor(){

@Override

protected void doJob() {

try {

pstmt = con.prepareStatement(sql);

rs=pstmt.executeQuery();

rs.next();

builder.append(rs.getString(1));

logger.info(builder.toString());

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}.execute();

return builder.toString();

} 

}