proxool的使用总结

在项目中使用proxool做数据源管理，这里记录下配置代码与需要注意的事项。

添加jar包：proxool-0.9.0RC3.jar 在WEB-INF下，创建proxool.xml文件，代码如下：

<?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>数据源名</alias>
        <driver-url>jdbc:mysql://localhost:3306/数据库名</driver-url>
	<driver-class>com.mysql.jdbc.Driver</driver-class>
        <driver-properties>
        <property name="user" value="用户名"/>
        <property name="password" value="密码"/>
        <property name="useUnicode" value="true"/>
        <property name="characterEncoding" value="UTF-8"/>
        </driver-properties>

        <house-keeping-sleep-time>40000</house-keeping-sleep-time>
        <maximum-connection-count>250</maximum-connection-count>
        <minimum-connection-count>3</minimum-connection-count>
        <maximum-connection-lifetime>3000000</maximum-connection-lifetime> <!-- 5 hours -->
        <simultaneous-build-throttle>5</simultaneous-build-throttle>
        <recently-started-threshold>400000</recently-started-threshold>
        <overload-without-refusal-lifetime>500000</overload-without-refusal-lifetime>
        <maximum-active-time>600000</maximum-active-time>
        <verbose>true</verbose>
        <trace>true</trace>
        <house-keeping-test-sql>select CURRENT_DATE</house-keeping-test-sql>
        <fatal-sql-exception>Fatal error</fatal-sql-exception>
        <prototype-count>2</prototype-count>
	<statistics-log-level>INFO</statistics-log-level>
    </proxool>
</something-else-entirely>

注：proxool.xml的配置参数详细说明请参考这里。

然后在web.xml文件中进行配置，添加如下代码：

<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> -->

上述代码中被注释掉的部分在开发过程中可以释放，如果释放，则会开启数据源监控页面，如果您的访问地址为www.xxx.com，那么数据源监控URL为：www.xxx.com/admin。网站发布到服务器上后，建议关闭该功能。

注意：如果工程中存在监听器，而监听器中调用了数据库中的数据，那么在系统启动的时候会报错

java.sql.SQLException: org.logicalcobwebs.proxool.ProxoolException: Attempt to refer to a unregistered pool by its alias ‘别名’

或者

java.sql.SQLException: No suitable driver found for '数据源名'

 这时的解决方案为：把proxool交给监听器进行处理：

新建类：

import java.io.File;
import java.util.Enumeration;
import java.util.Properties;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.logicalcobwebs.proxool.ProxoolException;
import org.logicalcobwebs.proxool.configuration.JAXPConfigurator;
import org.logicalcobwebs.proxool.configuration.PropertyConfigurator;

/**
 * @author wangtao
 */

public class ProxoolListener implements ServletContextListener {
	private static final Log LOG = LogFactory.getLog(ProxoolListener.class);

	private static final String XML_FILE_PROPERTY = "xmlFile";

	private static final String PROPERTY_FILE_PROPERTY = "propertyFile";

	private static final String AUTO_SHUTDOWN_PROPERTY = "autoShutdown";

	@SuppressWarnings("unused")
	private boolean autoShutdown = true;

	public void contextDestroyed(ServletContextEvent arg0) {
		System.out.println("destroy database pool....");
	}

	@SuppressWarnings("unchecked")
	public void contextInitialized(ServletContextEvent contextEvent) {
		System.out.println("init................");
		ServletContext context = contextEvent.getServletContext(); // 对应servlet的init方法中ServletConfig.getServletContext()
		String appDir = contextEvent.getServletContext().getRealPath("/");
		Properties properties = new Properties();

		Enumeration names = context.getInitParameterNames();
		while (names.hasMoreElements()) {
			String name = (String) names.nextElement();
			String value = context.getInitParameter(name);

			if (name.equals(XML_FILE_PROPERTY)) {
				try {
					File file = new File(value);
					if (file.isAbsolute()) {
						JAXPConfigurator.configure(value, false);
					} else {
						JAXPConfigurator.configure(appDir + File.separator + value, false);
					}
				} catch (ProxoolException e) {
					LOG.error("Problem configuring " + value, e);
				}
			} else if (name.equals(PROPERTY_FILE_PROPERTY)) {
				try {
					File file = new File(value);
					if (file.isAbsolute()) {
						PropertyConfigurator.configure(value);
					} else {
						PropertyConfigurator.configure(appDir + File.separator + value);
					}
				} catch (ProxoolException e) {
					LOG.error("Problem configuring " + value, e);
				}
			} else if (name.equals(AUTO_SHUTDOWN_PROPERTY)) {
				autoShutdown = Boolean.valueOf(value).booleanValue();
			} else if (name.startsWith("jdbc")) { // 此处以前是PropertyConfigurator.PREFIX改为jdbc,因为此源码是0.9.1版本的,与0.9RC3版本有点不一样
				properties.setProperty(name, value);
			}
		}

		if (properties.size() > 0) {
			try {
				PropertyConfigurator.configure(properties);
			} catch (ProxoolException e) {
				LOG.error("Problem configuring using init properties", e);
			}
		}
	}

}

然后web.xml中的配置如下：

<context-param>
	<param-name>xmlFile</param-name>
	<param-value>WEB-INF/proxool.xml</param-value>
</context-param>

获取数据源连接代码：

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

public class DBConnectionManager {
	private static Connection conn;
	public static Connection getConnection()
	  {
		try
	    {
	      conn = DriverManager.getConnection("proxool.数据源名");
	      if (conn == null)
	      {
	        throw new SQLException("数据库无值");
	      }

	    }
	    catch (Exception ex)
	    {
	      System.out.println(ex.getMessage());
	      ex.printStackTrace();
	    }

	    return conn;
	  }
}

参考资料：http://cbf0713.blog.163.com/blog/static/907789052010510105453412/

              http://sunnylocus.javaeye.com/blog/359570