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java程序很大一部分要操作数据库，为了提高性能操作数据库的时候，又不得不使用数据库连接池。数据库连接池有很多选择，c3p、dhcp、proxool等，druid作为一名后起之秀，凭借其出色的性能，也逐渐映入了大家的眼帘。接下来本教程就说一下druid的简单使用。
jar包下载、配置详解及配置示例
1. jar包获取
- 可以从 http://repo1.maven.org/maven2/com/alibaba/druid/ 下载最新的jar包。
- 如果想使用最新的源码编译，也可以从 https://github.com/alibaba/druid 下载源码，然后使用maven命令行，或者导入到IDEA中进行编译获得。
- 从maven的仓库中获取
<dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.6</version> </dependency>
2. 配置示例
spring.xml文件中加入：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">
<bean name = "transactionManager"
class ="org.springframework.jdbc.datasource.DataSourceTransactionManager" >
<property name = "dataSource" ref = "dataSource" ></ property >
</bean >
<bean id = "propertyConfigurer"
class ="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" >
<property name = "locations" >
<list>
<value > /WEB-INF/classes/dbconfig.properties </ value >
</list>
</property>
</bean>
<!-- 阿里 druid 数据库连接池 -->
<bean id = "dataSource" class = "com.alibaba.druid.pool.DruidDataSource" destroy-method = "close" >
<!-- 数据库基本信息配置 -->
<property name = "url" value = "${jdbc.url}" />
<property name = "username" value = "${jdbc.username}" />
<property name = "password" value = "${jdbc.password}" />
<property name = "driverClassName" value = "${jdbc.driverClassName}" />
<property name = "filters" value = "${jdbc.filters}" />
<!-- 最大并发连接数 -->
<property name = "maxActive" value = "${jdbc.maxActive}" />
<!-- 初始化连接数量 -->
<property name = "initialSize" value = "${jdbc.initialSize}" />
<!-- 配置获取连接等待超时的时间 -->
<property name = "maxWait" value = "${jdbc.maxWait}" />
<!-- 最小空闲连接数 -->
<property name = "minIdle" value = "${jdbc.minIdle}" />
<!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->
<property name = "timeBetweenEvictionRunsMillis" value ="${jdbc.timeBetweenEvictionRunsMillis}" />
<!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->
<property name = "minEvictableIdleTimeMillis" value ="${jdbc.minEvictableIdleTimeMillis}" />
<property name = "validationQuery" value = "${jdbc.validationQuery}" />
<property name = "testWhileIdle" value = "${jdbc.testWhileIdle}" />
<property name = "testOnBorrow" value = "${jdbc.testOnBorrow}" />
<property name = "testOnReturn" value = "${jdbc.testOnReturn}" />
<property name = "maxOpenPreparedStatements" value ="${jdbc.maxOpenPreparedStatements}" />
<!-- 打开 removeAbandoned 功能 -->
<property name = "removeAbandoned" value = "${jdbc.removeAbandoned}" />
<!-- 1800 秒，也就是 30 分钟 -->
<property name = "removeAbandonedTimeout" value ="${jdbc.removeAbandonedTimeout}" />
<!-- 关闭 abanded 连接时输出错误日志 -->
<property name = "logAbandoned" value = "${jdbc.logAbandoned}" />
</bean>
</beans>
jdbc.url=jdbc:mysql://localhost:3306/newm jdbc.driverClassName=com.mysql.jdbc.Driver jdbc.username=root jdbc.password=root jdbc.filters=stat jdbc.maxActive=20 jdbc.initialSize=1 jdbc.maxWait=60000 jdbc.minIdle=10 jdbc.maxIdle=15 jdbc.timeBetweenEvictionRunsMillis=60000 jdbc.minEvictableIdleTimeMillis=300000 jdbc.validationQuery=SELECT 'x' jdbc.testWhileIdle=true jdbc.testOnBorrow=false jdbc.testOnReturn=false jdbc.maxOpenPreparedStatements=20 jdbc.removeAbandoned=true jdbc.removeAbandonedTimeout=1800 jdbc.logAbandoned=true
<!-- 连接池 启用 Web 监控统计功能 start-->
<filter>
<filter-name>DruidWebStatFilter</filter-name>
<filter-class>com.alibaba.druid.support.http.WebStatFilter</filter-class>
<init-param>
<param-name>exclusions</param-name>
<param-value>*.js ,*.gif ,*.jpg ,*.png ,*.css ,*.ico ,/druid/*</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>DruidWebStatFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet>
<servlet-name>DruidStatView</servlet-name>
<servlet-class>com.alibaba.druid.support.http.StatViewServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>DruidStatView</servlet-name>
<url-pattern>/druid/*</url-pattern>
</servlet-mapping>
<!-- 连接池 启用 Web 监控统计功能 end-->
