proxool連接池配置詳解及例程

 

1. http://proxool.sourceforge.net/download.html 去下載最新的proxool-***.zip ， 將裏面的 lib/proxool-**.jar 添加到Eclipse的工程中.

2.proxool.xml文件放於src中，部署後處於WEB-INF/classes/文件夾中
<?xml version="1.0" encoding="ISO-8859-1"?>
<!-- the proxool configuration can be embedded within your own application's.
Anything outside the "proxool" tag is ignored. -->
<something-else-entirely>
  <proxool>
    <alias>MyPool</alias>
    <driver-url>jdbc:microsoft:sqlserver://localhost:2767;DatabaseName=camis;SelectMethod=cursor</driver-url>
    <driver-class>com.microsoft.jdbc.sqlserver.SQLServerDriver</driver-class>
    <driver-properties>
      <property name="user" value="sa"/>
      <property name="password" value="sa"/>
    </driver-properties>
    <maximum-connection-count>30</maximum-connection-count>
    <minimum-connection-count>10</minimum-connection-count>
    <house-keeping-sleep-time>90000</house-keeping-sleep-time>
    <prototype-count>5</prototype-count>
    <house-keeping-test-sql>select CURRENT_DATE</house-keeping-test-sql>
  </proxool>
</something-else-entirely>
 
3.在web.xml中添加,使連接池應用程序一開始就執行

  <servlet>
    <servlet-name>ServletConfigurator</servlet-name>
    <servlet-class>org.logicalcobwebs.proxool.configuration.ServletConfigurator</servlet-class>
    <init-param>
      <param-name>xmlFile</param-name>
      <param-value>WEB-INF/classes/proxool.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>

<!--連接池監聽-->
  <servlet>
    <servlet-name>proxool</servlet-name>
    <servlet-class>org.logicalcobwebs.proxool.admin.servlet.AdminServlet</servlet-class>
 </servlet>
 
  <servlet-mapping>
   <servlet-name>proxool</servlet-name>
   <url-pattern>/Admin/proxool/</url-pattern>
  </servlet-mapping>  
 
4.修改hibernate.cfg.xml文件,配置連接池

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration>

<session-factory>
<property name="hibernate.connection.provider_class">org.hibernate.connection.ProxoolConnectionProvider</property>
<property name="hibernate.proxool.pool_alias">MyPool</property>
<property name="hibernate.proxool.xml">proxool.xml</property>
<property name="show_sql">true</property>
<property name="dialect">org.hibernate.dialect.SQLServerDialect</property>
</session-factory>
</hibernate-configuration>

5.http://localhost:8080/camis//Admin/proxool/即可對連接池的情況進行監控

6.在普通jsp中使用，可以先寫一個通用的類

package com.db;
import java.sql.*;

import org.apache.log4j.*;
public class ProxoolAction {
 private static Connection conn;
 static Logger log=Logger.getLogger("ProxoolAction.class");
 public static Connection getConnection()
 {
  try
  {
  conn = DriverManager.getConnection("proxool.MyPool"); //其中MyPool是proxool中配置的連接池的別名,這裏如果沒有配置正確，會出現no suitable driver的異常

  }catch(Exception e)
 {
  log.error("無法獲取數據庫連接！"+e);
 }
  return conn;
 }
 public static void closeConnection(Connection conn)
 {
  if (conn == null) return;
  try
  {
   conn.close();
  }catch(Exception e)
  {
   log.error("不能關閉數據庫連接！",e);
  }
 }
 public static void closeStatement(Statement stmt)
 {
  if(stmt==null) return;
  try
  {
   stmt.close(); 
  }catch(Exception e)
  {
   log.error("不能關閉statement",e);
  }
 }
 public static void closeResultSet(ResultSet rs)
 {
  if(rs==null) return;
  try
   {
         rs.close();
      }catch (SQLException e)
      {
         log.error("不能關閉 resultset.", e);
      }
 }
}

7.在jsp中調用

<%
Connection conn=null;
PreparedStatement stmt=null;
ResultSet rs=null;
try
{
  conn=ProxoolAction.getConnection();
  stmt=conn.prepareStatement("select * from m_student");
  rs=stmt.executeQuery();
  while(rs.next())
  {
    out.println(rs.getString(2)+"<br>");
  }
  ProxoolAction.closeStatement(stmt);   //1.關閉statement
}catch(Exception e)
{
}finally
{
  ProxoolAction.closeResultSet(rs);
  ProxoolAction.closeStatement(stmt);  //2.關閉statement
  ProxoolAction.closeConnection(conn);
}

 %>

注意上面關閉statement時，如果已經關閉了一次，下面再調用關閉statement的方法，後臺會出現如下信息：

2007-09-13 10:29:02,000 [org.logicalcobwebs.proxool.MyPool]-[WARN] 000918 (05/20/00) - #185 registered a statement as closed which wasn't known to be open.

此時只要將1.關閉statement去掉即可.當然，如果在1處的後面繼續要使用這個statement，則應該將其關閉，否則在oracle數據庫中會出現超出遊標最大數的異常
8.相關步驟轉自http://www.blogjava.net/lyyb2001/archive/2007/06/26/126439.html,具體的配置文件變化較大。