今天在网上无意间看到了Druid连接池(http://code.alibabatech.com/wiki/display/Druid/Home)，正好闲来无事，在我们项目中配置了一下，特此记录一下。 我们项目用的SSH框架，数据库是Oracle，使用的是proxool连接池，所以改成druid还是很简单的。

1. 首先下载druid的jar包，我用的是0.2.9

2. 在src下添加druid.properties，内容如下： url:jdbc:oracle:thin:@localhost:1521:orcl driverClassName:oracle.jdbc.driver.OracleDriver username:username password:password
   filters:stat maxActive:20
   initialSize:1
   maxWait:60000
   minIdle:10
   timeBetweenEvictionRunsMillis:60000
   minEvictableIdleTimeMillis:300000
   validationQuery:SELECT 'x'
   testWhileIdle:true
   testOnBorrow:false
   testOnReturn:false
   poolPreparedStatements:true
   maxOpenPreparedStatements:20
   removeAbandoned:true
   removeAbandonedTimeout:1800
   logAbandoned:true

3. 编辑Spring的配置文件applicationContext.xml，修改连接池为druid。首先通过spring加载druid.properties,然后修改连接池：

   /WEB-INF/classes/druid.properties

   <property name="maxActive" value="${maxActive}" />
   <property name="initialSize" value="${initialSize}" />
   <property name="maxWait" value="${maxWait}" />
   <property name="minIdle" value="${minIdle}" />
   
   <property name="timeBetweenEvictionRunsMillis" value="${timeBetweenEvictionRunsMillis}" />
   <property name="minEvictableIdleTimeMillis" value="${minEvictableIdleTimeMillis}" />
   
   <property name="validationQuery" value="${validationQuery}" />
   <property name="testWhileIdle" value="${testWhileIdle}" />
   <property name="testOnBorrow" value="${testOnBorrow}" />
   <property name="testOnReturn" value="${testOnReturn}" />
   <property name="poolPreparedStatements" value="${poolPreparedStatements}" />
   <property name="maxOpenPreparedStatements" value="${maxOpenPreparedStatements}" />
   <property name="removeAbandoned" value="${removeAbandoned}" /> <!-- 打开removeAbandoned功能 -->
   <property name="removeAbandonedTimeout" value="${removeAbandonedTimeout}" /> <!-- 1800秒，也就是30分钟 -->
   <property name="logAbandoned" value="${logAbandoned}" /> <!-- 关闭abanded连接时输出错误日志 -->