GBase 8s数据库连接 - C3p0连接池

必需组件：

tomcat 7

数据库连接工具：

GBase 8s JDBC dbtjdbc_2.0.1a2_1.jar

开发环境：

Eclipse

配置前提

1，GBase 8s 数据库服务器已经正常启动

###1, 在eclipse环境中 新建 动态Web项目，使用Tomcat 7

###2, 将gbase 8s的jdbc jar包dbtjdbc_2.0.1a2_1.jar复制到tomcat的lib目录下，c3p0-0.9.5.2.jar和mchange-commons-java-0.2.11.jar也复制到tomcat的lib目录下（也可以放在WebContent/WEB-INF/lib目录下）

###3, 在WebContent/META-INF目录下，创建编写context.xml配置文件 具体内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<Context>
	<Resource name="jdbc/gbase01_c3p0" 
		auth="Container"
		type="com.mchange.v2.c3p0.ComboPooledDataSource"
    	factory="org.apache.naming.factory.BeanFactory"
    	driverClass="com.gbasedbt.jdbc.Driver"
		jdbcUrl="jdbc:gbasedbt-sqli://192.168.1.71:9088/c3p0db:GBASEDBTSERVER=gbase01;DB_LOCALE=zh_CN.utf8;CLIENT_LOCALE=zh_CN.utf8;IFX_LOCK_MODE_WAIT=30"
		user="gbasedbt"
		password="GBase123"
		minPoolSize="5"
		maxPoolSize="10"
		maxIdleTime="1800"
		initialPoolSize="5"
		testConnectionOnCheckin="true"
		idleConnectionTestPeriod="60"
	/>
</Context>

关于更多的c3p0的资源配置，参考：https://www.mchange.com/projects/c3p0/#configuration_properties ###4, 在WebContent/WEB-INF目录下，修改web.xml配置文件，增加以下内容

  <resource-ref>
	<description>C3P0 DB Connection</description>
	<res-ref-name>jdbc/gbase01_c3p0</res-ref-name>
	<res-type>javax.sql.DataSource</res-type>
	<res-auth>Container</res-auth>
  </resource-ref>

###5, 在Java Resources/src目录下，创建C3p0.java类，用于数据库连接。

具体内容如下：

package com.gbasedbt.db;

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

import javax.naming.InitialContext;
import javax.naming.NamingException;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class C3p0 {
	
	public static Connection getConn() throws NamingException, SQLException {
		Connection connection = null;
		InitialContext context = new InitialContext();
		ComboPooledDataSource dataSource = (ComboPooledDataSource)context.lookup("java:/comp/env/jdbc/gbase01_c3p0");
		connection = dataSource.getConnection();
		return connection;		
	}

}

###6， 在WebContent目录下，创建编写testC3p0.jsp动态网页文件

内容如下：

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<%@page import="com.gbasedbt.db.C3p0"%>
<%@page import="java.sql.SQLException"%>
<%@page import="java.sql.ResultSet"%>
<%@page import="java.sql.Statement"%>
<%@page import="java.sql.Connection"%>
<html>
<head>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>C3P0连接到GBase 8s数据库</title>
</head>
<body>
<p>c3p0 连接到GBase 8s数据库</p>
<%
	Connection connection = null;
	Statement statement = null;
	ResultSet resultSet = null;
	try{
		connection = C3p0.getConn();
		statement = connection.createStatement();
		resultSet  = statement.executeQuery("select first 10 tabname from systables");
		while(resultSet.next()){
			out.println("表名:  " + resultSet.getString(1) + "<br>");
		}		
	} catch (SQLException e){
		e.printStackTrace();
	} finally {
		if(resultSet != null){
			try{
				resultSet.close();
			} catch (Exception e){}
		}
		if(statement != null){
			try{
				statement.close();
			} catch (Exception e){}
		}
		if(connection != null){
			try{
				connection.close();
			} catch (Exception e){}
		}		
	}
%>
</body>
</html>

完成配置，测试数据库连接池的连接。