数据库连接池proxool的两种使用方式

数据库连接池可以通过两种方式来应用，针对web应用和非web应用而来。

非web应用的数据库连接池配置

第一种方式：工厂类

非web应用可以使用工厂模式将数据库连接创建封装在一个工具类中，工具类中又使用单例模式来创建加载驱动，代码如下：

工厂类：ConnectPoolFactory.java

 import java.io.InputStream;
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.util.Properties;

 import org.logicalcobwebs.proxool.configuration.PropertyConfigurator;

 public class ConnectPoolFactory {

     private static ConnectPoolFactory connectPoolFactory=null;

     private ConnectPoolFactory() {//构造方法
         init();
     }

     public void init(){//把properties文件加载到链接对象
         InputStream is = ConnectPoolFactory.class.getResourceAsStream("/proxool.properties");
         Properties properties = new Properties();
         try {
             properties.load(is);
             PropertyConfigurator.configure(properties);
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     public static  ConnectPoolFactory getInstance(){//单例模式
         if(null == connectPoolFactory){
             connectPoolFactory = new ConnectPoolFactory();
         }

         return connectPoolFactory;
     }

     public Connection getConnect(){
         Connection conn=null;
         try {
             Class.forName("org.logicalcobwebs.proxool.ProxoolDriver");// 加载数据库连接池配备的驱动
             conn = DriverManager.getConnection("proxool.test");//proxool为配置文件名，test为连接池别名
         } catch (Exception e) {
             e.printStackTrace();
         }
         return conn;
     }

 }

配置文件：proxool.properties

  jdbc-1.proxool.alias=test
  #jdbc-1.proxool.driver-class=oracle.jdbc.OracleDriver
  #jdbc-1.proxool.driver-url=jdbc:oracle:thin:@127.0.0.1:1521:orcl
  jdbc-1.proxool.driver-class=com.mysql.jdbc.Driver
  jdbc-1.proxool.driver-url=jdbc:mysql://localhost:3306/db_course
  jdbc-1.user=root
  jdbc-1.password=root

  jdbc-1.proxool.maximum-connection-count=8
  jdbc-1.proxool.minimum-connection-count=5
  jdbc-1.proxool.prototype-count=4
  jdbc-1.proxool.verbose=true
  jdbc-1.proxool.statistics=10s,1m,1d
  jdbc-1.proxool.statistics-log-level=error

然后通过工厂类创建工厂对象，通过工厂对象获取连接池实例，通过实例创建连接

测试类：ProxoolTest.java

 public class ProxoolTest {
     public static void main(String[] args) {
         ConnectPoolFactory factory = ConnectPoolFactory.getInstance();
         Connection connect = factory.getConnect();
         System.out.println("ProxoolTest.main(conncet): " + connect);
     }
 }

第二种方式：工具类中加载

工具类：DBUtil.java

 public class DBUtil {
     static {
         InputStream is = DBUtil.class
                 .getResourceAsStream("/proxool.properties");
         Properties properties = new Properties();
         try {
             properties.load(is);
             PropertyConfigurator.configure(properties);
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     /**
      * 获取数据库连接
      *
      * @return
      */
     public static Connection getConn() {
         Connection conn = null;
         try {
             Class.forName("org.logicalcobwebs.proxool.ProxoolDriver");
             conn = DriverManager.getConnection("proxool.test");
         } catch (SQLException e) {
             e.printStackTrace();
         } catch (ClassNotFoundException e) {
             e.printStackTrace();
         }
         return conn;
     }

     /**
      * 获取sql语句发送器
      *
      * @param conn
      * @return
      */
     public static Statement getStmt(Connection conn) {
         Statement stmt = null;
         try {
             stmt = conn.createStatement();
         } catch (SQLException e) {
             e.printStackTrace();
         }
         return stmt;
     }

     /**
      * 获取预处理发送器
      *
      * @param conn
      * @param sql
      * @return
      */
     public static PreparedStatement getPstmt(Connection conn, String sql) {
         PreparedStatement pstmt = null;
         try {
             pstmt = conn.prepareStatement(sql);
         } catch (SQLException e) {
             e.printStackTrace();
         }
         return pstmt;
     }

     /**
      * 动态绑定参数
      *
      * @param pstmt
      * @param params
      */
     public static void bindParam(PreparedStatement pstmt, Object... params) {
         for (int i = 0; i < params.length; i++) {
             try {
                 pstmt.setObject(i + 1, params[i]);
             } catch (SQLException e) {
                 e.printStackTrace();
             }
         }
     }

     /**
      * 关闭资源
      * @param autoCloseables 实现了AutoCloseable接口的实现类对象
      */
     public static void closeAll(AutoCloseable...autoCloseables) {
         for (AutoCloseable autoCloseable : autoCloseables) {
             if(autoCloseable!=null){
                 try {
                     autoCloseable.close();
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
             }
         }
     }
 }

在web应用中使用数据库连接池

proxool.properties配置文件是不可少的，但是DBUtil.java中的静态代码块就不再需要了。

不过要在web.xml中添加如下代码：

 <!-- 配置连接池信息 -->
   <servlet>
     <servlet-name>servletConfigurator</servlet-name>
     <servlet-class>org.logicalcobwebs.proxool.configuration.ServletConfigurator</servlet-class>
     <init-param>
         <param-name>propertyFile</param-name>
         <param-value>WEB-INF/classes/proxool.properties</param-value>
     </init-param>
     <load-on-startup>1</load-on-startup><!-- 应用启动时加载配置信息 -->
   </servlet>

   <!-- 监控连接池 -->
   <servlet>
     <servlet-name>adminServlet</servlet-name>
     <servlet-class>org.logicalcobwebs.proxool.admin.servlet.AdminServlet</servlet-class>
   </servlet>
   <servlet-mapping>
     <servlet-name>adminServlet</servlet-name>
     <url-pattern>/admin</url-pattern>
   </servlet-mapping>

其中<url-pattern>/admin</url-pattern>用来配置访问监控连接池页面