proxool一个数据库连接池框架,提供了对你选择的其它类型的驱动程序的连接池封装。可以非常简单的移植到现存的代码中。完全可配置。快速,成熟,健壮。可以透明地为你现存的JDBC驱动程序增加连接池功能。到目前为止最新版本是proxool 0.9.1,可从官网下载最新版本http://proxool.sourceforge.net
一、配置proxool.xml文件
- <?xml version="1.0" encoding="UTF-8"?>
- <!--
- the proxool configuration can be embedded within your own
- application's. Anything outside the "proxool" tag is ignored.
- -->
- <something-else-entirely>
- <proxool>
- <alias>dbname</alias>
- <driver-url>jdbc:oracle:thin:@127.0.0.1:1521:testdb</driver-url>
- <driver-class>oracle.jdbc.driver.OracleDriver</driver-class>
- <driver-properties>
- <property name="user" value="username" />
- <property name="password" value="password" />
- </driver-properties>
-
- <maximum-connection-count>100</maximum-connection-count>
-
- <minimum-connection-count>10</minimum-connection-count>
-
- <house-keeping-sleep-time>90000</house-keeping-sleep-time>
-
- <maximum-new-connections>10</maximum-new-connections>
-
- <prototype-count>5</prototype-count>
-
- <test-before-use>true</test-before-use>
-
- <house-keeping-test-sql>select sysdate from dual</house-keeping-test-sql>
- </proxool>
- </something-else-entirely>
二、配置web.xml
- <?xml version="1.0" encoding="UTF-8"?>
- <web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
- http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
- <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/proxool.xml</param-value>
- </init-param>
- <load-on-startup>1</load-on-startup>
- </servlet>
-
- <servlet>
- <servlet-name>Admin</servlet-name>
- <servlet-class>
- org.logicalcobwebs.proxool.admin.servlet.AdminServlet
- </servlet-class>
- </servlet>
- <servlet-mapping>
- <servlet-name>Admin</servlet-name>
- <url-pattern>/admin</url-pattern>
- </servlet-mapping>
-
- <security-constraint>
- <web-resource-collection>
- <web-resource-name>proxool</web-resource-name>
- <url-pattern>/admin</url-pattern>
- </web-resource-collection>
- <auth-constraint>
- <role-name>manager</role-name>
- </auth-constraint>
- </security-constraint>
- <login-config>
- <auth-method>BASIC</auth-method>
- <realm-name>proxool manager Application</realm-name>
- </login-config>
- <security-role>
- <description>The role that is required to log in to the Manager Application</description>
- <role-name>manager</role-name>
- </security-role>
- <error-page>
- <error-code>401</error-code>
- <location>/401.jsp</location>
- </error-page>
- </web-app>
ServletConfigurator:加载并初始化proxool.xml文件,因为它是连接数据库的.其他很多模块都用到数据,所以必须首先加载它
load-on-startup:数值越小,就会先被加载初始化
Admin:监控数据库连接池的连接情况
//获得数据库连接的语句
Connection conn=DriverManager.getConnection("proxool.dbname");
注意:在401.jsp页面中必须加
<%
response.setHeader("WWW-Authenticate", "Basic realm=\"Tomcat Manager Application\"");
%>这句话,否则在访问/admin察看连接池信息时,会直接跳转到401.jsp页面。我们是想让访问admin/的用户必须输入用户名和密码,且必须是manager角色,三次输入不正确才会跳到401.jsp页面,如图
输入正确用户名和密码后才能看到proxool池的信息
三、更详细的proxool.xml的配置属性说明:
- <?xml version="1.0" encoding="ISO-8859-1"?>
- <!--
- Properties for Proxool Configurator testing. Defines the same parameters as
- TestHelper.buildCompleteAlternativeProperties()
- -->
- <something-else-entirely xmlns="http://sumthin.else.entirely" xmlns:proxool="The latest version is available at http://proxool.sourceforge.net/xml-namespace">
- <proxool:proxool>
- <proxool:alias>xml-test-ns</proxool:alias>
- <proxool:driver-url>jdbc:hsqldb:db/test</proxool:driver-url>
- <proxool:driver-class>org.hsqldb.jdbcDriver</proxool:driver-class>
- <proxool:driver-properties>
- <proxool:property name="user" value="sa"/>
- <proxool:property name="password" value=""/>
- </proxool:driver-properties>
- <proxool:house-keeping-sleep-time>40000</proxool:house-keeping-sleep-time>
- <proxool:house-keeping-test-sql>select CURRENT_DATE</proxool:house-keeping-test-sql>
- <proxool:maximum-connection-count>10</proxool:maximum-connection-count>
- <proxool:minimum-connection-count>3</proxool:minimum-connection-count>
- <proxool:maximum-connection-lifetime>18000000</proxool:maximum-connection-lifetime>
- <proxool:simultaneous-build-throttle>5</proxool:simultaneous-build-throttle>
- <proxool:recently-started-threshold>40000</proxool:recently-started-threshold>
- <proxool:overload-without-refusal-lifetime>50000</proxool:overload-without-refusal-lifetime>
- <proxool:maximum-active-time>60000</proxool:maximum-active-time>
- <proxool:verbose>true</proxool:verbose>
- <proxool:trace>true</proxool:trace>
- <proxool:fatal-sql-exception>Fatal error</proxool:fatal-sql-exception>
- <proxool:prototype-count>2</proxool:prototype-count>
- </proxool:proxool>
- <nothing-to-do-with-proxool>
- <proxool:proxool>
- <proxool:alias>xml-test-ns-2</proxool:alias>
- <proxool:driver-url>jdbc:hsqldb:db/test</proxool:driver-url>
- <proxool:driver-class>org.hsqldb.jdbcDriver</proxool:driver-class>
- <proxool:driver-properties>
- <proxool:property name="user" value="sa"/>
- <proxool:property name="password" value=""/>
- </proxool:driver-properties>
- <proxool:house-keeping-sleep-time>40000</proxool:house-keeping-sleep-time>
- <proxool:house-keeping-test-sql>select CURRENT_DATE</proxool:house-keeping-test-sql>
- <proxool:maximum-connection-count>10</proxool:maximum-connection-count>
- <proxool:minimum-connection-count>3</proxool:minimum-connection-count>
- <proxool:maximum-connection-lifetime>18000000</proxool:maximum-connection-lifetime>
- <proxool:simultaneous-build-throttle>5</proxool:simultaneous-build-throttle>
- <proxool:recently-started-threshold>40000</proxool:recently-started-threshold>
- <proxool:overload-without-refusal-lifetime>50000</proxool:overload-without-refusal-lifetime>
- <proxool:maximum-active-time>60000</proxool:maximum-active-time>
- <proxool:verbose>true</proxool:verbose>
- <proxool:trace>true</proxool:trace>
- <proxool:fatal-sql-exception>Fatal error</proxool:fatal-sql-exception>
- <proxool:prototype-count>2</proxool:prototype-count>
- </proxool:proxool>
- </nothing-to-do-with-proxool>
- </something-else-entirely>
属性列表说明:
fatal-sql-exception: 它是一个逗号分割的信息片段.当一个SQL异常发生时,他的异常信息将与这个信息片段进行比较.如果在片段中存在,那么这个异常将被认为是个致命错误(Fatal SQL Exception ).这种情况下,数据库连接将要被放弃.无论发生什么,这个异常将会被重掷以提供给消费者.用户最好自己配置一个不同的异常来抛出.
fatal-sql-exception-wrapper-class:正如上面所说,你最好配置一个不同的异常来重掷.利用这个属性,用户可以包装SQLException,使他变成另外一个异常.这个异常或者继承SQLException或者继承字RuntimeException.proxool自带了2个实现:'org.logicalcobwebs.proxool.FatalSQLException' 和'org.logicalcobwebs.proxool.FatalRuntimeException' .后者更合适.
house-keeping-sleep-time: house keeper 保留线程处于睡眠状态的最长时间,house keeper 的职责就是检查各个连接的状态,并判断是否需要销毁或者创建.
house-keeping-test-sql: 如果发现了空闲的数据库连接.house keeper 将会用这个语句来测试.这个语句最好非常快的被执行.如果没有定义,测试过程将会被忽略。
injectable-connection-interface: 允许proxool实现被代理的connection对象的方法.
injectable-statement-interface: 允许proxool实现被代理的Statement 对象方法.
injectable-prepared-statement-interface: 允许proxool实现被代理的PreparedStatement 对象方法.
injectable-callable-statement-interface: 允许proxool实现被代理的CallableStatement 对象方法.
jmx: 略
jmx-agent-id: 略
jndi-name: 数据源的名称
maximum-active-time: 如果housekeeper 检测到某个线程的活动时间大于这个数值.它将会杀掉这个线程.所以确认一下你的服务器的带宽.然后定一个合适的值.默认是5分钟.
maximum-connection-count: 最大的数据库连接数.
maximum-connection-lifetime: 一个线程的最大寿命.
minimum-connection-count: 最小的数据库连接数
overload-without-refusal-lifetime: 略
prototype-count: 连接池中可用的连接数量.如果当前的连接池中的连接少于这个数值.新的连接将被建立(假设没有超过最大可用数).例如.我们有3个活动连接2个可用连接,而我们的prototype-count是4,那么数据库连接池将试图建立另外2个连接.这和 minimum-connection-count不同. minimum-connection-count把活动的连接也计算在内.prototype-count 是spare connections 的数量.
recently-started-threshold: 略
simultaneous-build-throttle: 略
statistics: 连接池使用状况统计。 参数“10s,1m,1d”
statistics-log-level: 日志统计跟踪类型。 参数“ERROR”或 “INFO”
test-before-use: 略
test-after-use: 略
trace: 如果为true,那么每个被执行的SQL语句将会在执行期被log记录(DEBUG LEVEL).你也可以注册一个ConnectionListener (参看ProxoolFacade)得到这些信息.
verbose: 详细信息设置。 参数 bool 值