-. addObjectCreate(element 경로, 자바빈크래스) : 어떤 element 경로를 자바빈클래스로 매칭?

-. addSetProperties(element 속성명, 자바빈프로퍼티명) : 어떤 element 속성을 자바빈 변수에 설정?

-. addBeanPropertySetter(element 경로, 자바빈프로퍼티명) : 어떤 element 경로를 자바빈 변수에 설정?

-. addSetNext(element 경로, 자바빈함수) : 어떤 element 경로를 자바빈 함수에?

<a>                 -- Matches pattern "a"
    <b>             -- Matches pattern "a/b"
        <c/>        -- Matches pattern "a/b/c"
        <c/>        -- Matches pattern "a/b/c"
    </b>
    <b>             -- Matches pattern "a/b"
        <c/>        -- Matches pattern "a/b/c"
        <c/>        -- Matches pattern "a/b/c"
        <c/>        -- Matches pattern "a/b/c"
    </b>
</a>

...

digester.addObjectCreate("a/b", B.class);

digester.addBeanPropertySetter("a/b/c", "c");

...

<?xml version="1.0" encoding="EUC-KR"?>

<connection-sources>
   <description>This script is a connection description</description>

   <JDBCConnectionPool name="mysql">
      <description>Mysql Connection Source</description>
      <defaultAutoCommit>true</defaultAutoCommit>
      <defaultReadOnly>false</defaultReadOnly>
      <driverClassName>org.gjt.mm.mysql.Driver</driverClassName>
      <maxActive>10</maxActive>
      <maxIdle>10</maxIdle>
      <maxWait>10000</maxWait>
      <username>unicorn</username>
      <password>iloveyou</password>
      <url>jdbc:mysql://localhost/unicorn</url>
   </JDBCConnectionPool>

   <JDBCConnectionPool name="oracle">
      <description>Oracle Connection Source</description>
      <defaultAutoCommit>true</defaultAutoCommit>
      <defaultReadOnly>false</defaultReadOnly>
      <driverClassName>oracle.jdbc.driver.OracleDriver</driverClassName>
      <maxActive>10</maxActive>
      <maxIdle>10</maxIdle>
      <maxWait>10000</maxWait>
      <username>unicorn</username>
      <password>iloveyoutoo</password>
      <url>jdbc:oracle:thin:@localhost:1521:unicorn</url>
   </JDBCConnectionPool>

</connection-sources>

<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app
    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
    "http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>

  <servlet>
     <servlet-name>connectioninitialize</servlet-name>
     <servlet-class>db.ConnectionInitialize</servlet-class>
     <init-param>
        <param-name>config</param-name>
        <param-value>C:\Tomcat 5.0\webapps\ROOT\WEB-INF\classes\config.xml</param-value>
     </init-param>
     <load-on-startup>1</load-on-startup>
  </servlet>
   
</web-app>

package db.jdbc;

import java.util.HashMap;

public class ConnectionSources {

	private String description;
	private HashMap source = new HashMap();
	
	public void setDescription(String description) {
		this.description = description;
	}
	
	public void addSource(JDBCConnectionPool source) {
		this.source.put(source.getName(), source);
	}
	
	public String getDescription() {
		return this.description;
	}
	
	public JDBCConnectionPool getSource(String name) {
		return (JDBCConnectionPool)this.source.get(name);
	}
}

package db.jdbc;

public class JDBCConnectionPool {

	private String name;
	private String description;
	private boolean defaultAutoCommit;
	private boolean defaultReadOnly;
	private String driverClassName;
	private int maxActive;
	private int maxIdle;
	private int maxWait;
	private String username;
	private String password;
	private String url;
	
       //for debug
	public void print() {
		String toString = "name : "+name+"\n"+
			"description : "+description+"\n"+
			"defaultAutoCommit : "+defaultAutoCommit+"\n"+	
			"defaultReadOnly : "+defaultReadOnly+"\n"+	
			"driverClassName : "+driverClassName+"\n"+	
			"maxActive : "+maxActive+"\n"+	
			"maxIdle : "+maxIdle+"\n"+	
			"maxWait : "+maxWait+"\n"+	
			"username : "+username+"\n"+	
			"password : "+password+"\n"+	
			"url : "+url;
		System.out.println(toString);
	}
	
	public void setName(String name) {
		this.name = name;
	}
	
	public void setDescription(String description) {
		this.description = description;
	}
	
	public void setDefaultAutoCommit(boolean defaultAutoCommit) {
		this.defaultAutoCommit = defaultAutoCommit;
	}

	public void setDefaultReadOnly(boolean defaultReadOnly) {
		this.defaultReadOnly = defaultReadOnly;
	}
	
	public void setDriverClassName(String driverClassName) {
		this.driverClassName = driverClassName;
	}
	
	public void setMaxActive(int maxActive) {
		this.maxActive = maxActive;
	}
	
	public void setMaxIdle(int maxIdle) {
		this.maxIdle = maxIdle;
	}
	
	public void setMaxWait(int maxWait) {
		this.maxWait = maxWait;
	}
	
	public void setUsername(String username) {
		this.username = username;
	}
	
	public void setPassword(String password) {
		this.password = password;
	}
	
	public void setUrl(String url) {
		this.url = url;
	}
	
	public String getName() {
		return this.name;
	}
	
	public String getDescription() {
		return this.description;
	}
	
	public boolean getDefaultAutoCommit() {
		return this.defaultAutoCommit;
	}
	
	public boolean getDefaultReadOnly() {
		return this.defaultReadOnly;
	}
	
	public String getDriverClassName() {
		return this.driverClassName;
	}
	
	public int getMaxActive() {
		return this.maxActive;
	}
	
	public int getMaxIdle() {
		return this.maxIdle;
	}
	
	public int getMaxWait() {
		return this.maxWait;
	}
	
	public String getUsername() {
		return this.username;
	}
	
	public String getPassword() {
		return this.password;
	}
	
	public String getUrl() {
		return this.url;
	}
}

package db;

import java.sql.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

import org.apache.commons.pool.ObjectPool;
import org.apache.commons.pool.impl.GenericObjectPool;
import org.apache.commons.dbcp.ConnectionFactory;
import org.apache.commons.dbcp.PoolingDriver;
import org.apache.commons.dbcp.PoolableConnectionFactory;
import org.apache.commons.dbcp.DriverManagerConnectionFactory;

import org.apache.commons.digester.Digester;
import java.io.*;
import org.xml.sax.SAXException;

import db.jdbc.ConnectionSources;
import db.jdbc.JDBCConnectionPool;

public class ConnectionInitialize extends HttpServlet {

	public void init() throws ServletException {

		String config = null;
		// web.xml의 배치스크립트의 파라미터이름을 가져온다
		Enumeration names = getServletConfig().getInitParameterNames();
		do {
			if(!names.hasMoreElements())
			break;
			String name = (String)names.nextElement();
			String value = getServletConfig().getInitParameter(name).trim();

			System.out.println(name+" : "+value);

			// config에 정의된 XML 파일을 가져온다
			if (name.startsWith("config"))
 				config = value;
		} while(true);

		//Digester를 생성하고
		Digester digester = new Digester();
		//XML 유효성을 검증할것인가?
		digester.setValidating(false);

		//connection-sources 요소를 ConnectionSources.class 객체에 저장하겠다
		digester.addObjectCreate("connection-sources",
		                          ConnectionSources.class);

		//connection-sources/description 요소를
		//ConnectionSources.class의 description 변수에 저장하겠다
		digester.addBeanPropertySetter("connection-sources/description",
						"description");

		//connection-sources/JDBCConnectionPool 요소를 JDBCConnectionPool.class 객체에저장하겠다
		digester.addObjectCreate("connection-sources/JDBCConnectionPool",
		                         db.jdbc.JDBCConnectionPool.class);

		//connection-sources/JDBCConnectionPool 요소의 name 속성을
		//JDBCConnectionPool.class의 name 변수에 저장하겠다
		digester.addSetProperties("connection-sources/JDBCConnectionPool", "name", "name");

		//connection-sources/JDBCConnectionPool/description 을
		//JDBCConnectionPool.class 객에의 description 변수에 저장하겠다
		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/description",
                                       "description");

		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/defaultAutoCommit",
                                       "defaultAutoCommit");
		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/defaultReadOnly",
                                       "defaultReadOnly");
		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/driverClassName",
                                       "driverClassName");
		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/maxActive",
                                       "maxActive");
		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/maxIdle",
                                       "maxIdle");
		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/maxWait",
                                       "maxWait");
		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/username",
                                       "username");
		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/password",
                                       "password");
		digester.addBeanPropertySetter("connection-sources/JDBCConnectionPool/url", "url");

		//connection-sources/JDBCConnectionPool을
		//ConnectionResources.class의 addSource를 이용하여 반복적으로 추가하겠다
		digester.addSetNext("connection-sources/JDBCConnectionPool", "addSource");

		try {
			File file = new File(config);
			//digester 파싱 및 결과 리턴
			ConnectionSources connectionSources =
                                                             (ConnectionSources)digester.parse(file);

			System.out.println(connectionSources.getDescription());
			JDBCConnectionPool mysql = connectionSources.getSource("mysql");
			mysql.print(); //디버깅
			JDBCConnectionPool oracle = connectionSources.getSource("oracle");
			oracle.print(); //디버깅

			//이부분 이하는 Commons-dbcp 부분을 참조하기 바란다
			setupDriver(mysql.getName(),
				mysql.getDriverClassName(),
				mysql.getUrl(),
				mysql.getUsername(),
				mysql.getPassword(),
				mysql.getDefaultAutoCommit(),
				mysql.getDefaultReadOnly(),
				mysql.getMaxActive(),
				mysql.getMaxIdle(),
				mysql.getMaxWait());

			setupDriver(oracle.getName(),
				oracle.getDriverClassName(),
				oracle.getUrl(),
				oracle.getUsername(),
				oracle.getPassword(),
				oracle.getDefaultAutoCommit(),
				oracle.getDefaultReadOnly(),
				oracle.getMaxActive(),
				oracle.getMaxIdle(),
				oracle.getMaxWait());

		} catch (FileNotFoundException filenotfoundexception) {
			System.out.println("Config file not found");
			filenotfoundexception.printStackTrace();
		} catch (Exception exception) {
			exception.printStackTrace();
		}
	}

	public void setupDriver(String poolName,
			String driverClassName,
			String url,
			String username,
			String password,
			boolean defaultAutoCommit,
			boolean defaultReadOnly,
			int maxActive,
			int maxIdle,
			long maxWait) throws Exception {
		try {
		    Class.forName(driverClassName);
		} catch (ClassNotFoundException classnotfoundexception) {
			System.out.println(driverClassName+" is not found");
		    classnotfoundexception.printStackTrace();
		    throw classnotfoundexception;
		}
		
		GenericObjectPool connectionPool = new GenericObjectPool(null);
		connectionPool.setMaxActive(maxActive);
		connectionPool.setMaxIdle(maxIdle);
		connectionPool.setMaxWait(maxWait);
		
		ConnectionFactory connectionFactory
			= new DriverManagerConnectionFactory(url, username, password);
		
		PoolableConnectionFactory poolableConnectionFactory
			= new PoolableConnectionFactory(connectionFactory,
		                                   connectionPool,
		                                   null,
		                                   null,
		                                   defaultReadOnly,
		                                   defaultAutoCommit);
		
		Class.forName("org.apache.commons.dbcp.PoolingDriver");
		PoolingDriver driver = (PoolingDriver) DriverManager.getDriver("jdbc:apache:commons:dbcp:");
		
		driver.registerPool(poolName,connectionPool);    
	}
}

package db;

public interface ConnectionContext {
	public java.sql.Connection getConnection();
	public void rollback();
	public void commit();
	public void release();
}

package db;

import java.sql.Connection;
import java.sql.DriverManager;
import javax.sql.DataSource;

public class ConnectionResource implements ConnectionContext {
	private Connection connection = null;
	private boolean transaction = false;

    public ConnectionResource(String poolName) throws Exception {
    	init(false, poolName);	
    }
    
    public ConnectionResource(boolean transaction, String poolName) throws Exception {
    	init(transaction, poolName);
    }
    
    public void init(boolean transaction, String poolName) throws Exception {
    	this.transaction = transaction;
    	connection = DriverManager.getConnection("jdbc:apache:commons:dbcp:"+poolName);
       if (transaction) connection.setAutoCommit(false);
    	if (connection == null) throw new Exception("fail to get connection");
    }
    	
    public Connection getConnection() {		
		return connection;
    }

	public void rollback() {
		if (transaction) {
			if (connection != null) try { connection.rollback(); } catch (Exception e) {}
		}
	}

	public void commit() {
		if (transaction) {
			if (connection != null) try { connection.commit(); } catch (Exception e) {}
		}
	}

	public void release() { {
		if (connection != null) {
			if (transaction) {
				try { connection.setAutoCommit(true); } catch (Exception e) {}
			}
			try { connection.close(); } catch (Exception e) {}
		}
    }
}

<%@ page contentType="text/html;charset=EUC_KR" %>
<%@ page import="java.sql.*,db.*" %>

<%

ConnectionContext mysqlContext = new ConnectionResource("mysql");
// 혹은 ConnectionContext oracleContext = new ConnectionResource("oracle");

Connection connection = null;

try {

    connection = mysqlContext.getConnection();
    out.println(connection);

} catch (Exception exception) {
    exception.printStackTrace();
} finally {
    if (connection != null) try { mysqlContext.release(); } catch (Exception exception) {}
}

%>