Java数据库连接池之proxool_动力节点Java学院整理

package com.bjpowernode.util;  
import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.PreparedStatement; 
import java.sql.ResultSet; 
import java.sql.ResultSetMetaData; 
import java.sql.SQLException; 
import java.util.ArrayList; 
import java.util.HashMap; 
import java.util.List; 
import java.util.Map; 
public class DBLink { 
  private Connection connection; 
  private PreparedStatement preparedStatement; 
  private ResultSet resultSet; 
  static{ 
    try { 
      Class.forName("org.logicalcobwebs.proxool.ProxoolDriver"); //加载驱动  
    }catch (ClassNotFoundException e) { 
      System.out.println("加载驱动失败！"); 
      e.printStackTrace(); 
    } 
  } 
  private Connection getConn(){ 
    try { 
      if(connection==null||connection.isClosed()){ 
        connection = DriverManager.getConnection("proxool.mysqlsource");  //获取连接  
      } 
    } catch (SQLException e) { 
      System.out.println("获取连接失败！"); 
      e.printStackTrace(); 
    } 
    return connection; 
  } 
  public List<Map<String, Object>> select(String sql, Object [] params){ 
    List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(); 
    try{ 
      connection = this.getConn(); 
      preparedStatement = connection.prepareStatement(sql); 
      if(params != null){ 
        for(int i =0; i<params.length; i++){ 
          preparedStatement.setObject(i+1, params[i]);//逐一给问号赋值 
        } 
      } 
      resultSet = preparedStatement.executeQuery(); 
      ResultSetMetaData rsmd = resultSet.getMetaData(); 
      int columnCount = rsmd.getColumnCount(); 
      while(resultSet.next()){ 
        Map<String, Object> map = new HashMap<String, Object>(); 
        for(int i =1; i<=columnCount;i++){ 
          String columnName = rsmd.getColumnName(i); 
          Object obj = null; 
          if(rsmd.getColumnTypeName(i).equals("DATE")){ 
            obj = resultSet.getString(columnName); 
          }else{ 
            obj = resultSet.getObject(columnName); 
          } 
          map.put(columnName, obj); 
        } 
        list.add(map); 
      } 
    }catch(SQLException e){ 
      e.printStackTrace(); 
    }finally{ 
      close(); 
    } 
    return list; 
  } 
  private void close(){ 
    try { 
      if(resultSet != null){ 
        resultSet.close(); 
      } 
    } catch (SQLException e) { 
      e.printStackTrace(); 
    } 
    try { 
      if(preparedStatement != null){ 
        preparedStatement.close(); 
      } 
    } catch (SQLException e) { 
      e.printStackTrace(); 
    } 
    try { 
      connection.close(); 
    } catch (SQLException e) { 
      e.printStackTrace(); 
    } 
  } 
} 

<?xml version="1.0" encoding="UTF-8"?> 
<proxool-config> 
  <proxool> 
    <alias>mysqlsource</alias> 
    <driver-url>jdbc:mysql://localhost:3306/test</driver-url> 
    <driver-class>com.mysql.jdbc.Driver</driver-class> 
    <driver-properties> 
      <property name="user" value="root" /> 
      <property name="password" value="root" /> 
    </driver-properties> 
    <!-- 保留线程处于睡眠状态的最长时间 --> 
    <house-keeping-sleep-time>60000</house-keeping-sleep-time> 
    <maximum-connection-count>30</maximum-connection-count> 
    <minimum-connection-count>10</minimum-connection-count> 
    <!-- 连接池中可用的连接数量（空闲状态） --> 
    <prototype-count>5</prototype-count> 
    <maximum-new-connections>1</maximum-new-connections> 
    <simultaneous-build-throttle>1</simultaneous-build-throttle> 
    <!-- 连接池使用状态 --> 
    <statistics>30s,10m,1d</statistics> 
    <!-- 连接池日志类型 --> 
    <statistics-log-level>ERROR</statistics-log-level> 
    <!-- 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) --> 
    <trace>true</trace> 
    <house-keeping-test-sql>select CURRENT_DATE</house-keeping-test-sql> 
  </proxool> 
</proxool-config> 

<?xml version="1.0" encoding="UTF-8"?> 
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
  http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> 
 
  <!-- 连接池 --> 
  <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> 
   
  <welcome-file-list> 
    <welcome-file>index.jsp</welcome-file> 
  </welcome-file-list> 
</web-app> 

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> 
<%@page import="com.bjpowernode.util.DBLink,java.util.List,java.util.Map"%> 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 
<html> 
  <head> 
    <title>首页</title> 
  </head> 
 
  <body> 
    <table width="100%" border="1px"> 
      <tr> 
        <th>序号  </th><th>班级名称</th><th>开班日期</th><th>结束日期</th><th>状态</th><th>操作</th> 
      </tr> 
      <% 
        String sql = "SELECT id, class_name, begin_date, end_date, state FROM class "; 
        DBLink db = new DBLink(); 
        List<Map<String, Object>> list = db.select(sql, null); 
        int index = 0; 
        for (Map<String, Object> map : list) { 
          index = index + 1; 
          int id = Integer.parseInt(map.get("id").toString()); 
          String className = map.get("class_name").toString(); 
          String beginDate = map.get("begin_date").toString(); 
          String endDate = map.get("end_date").toString(); 
          int state = Integer.parseInt(map.get("state").toString()); 
          String stateName = (state == 0 ? "未启用" : "启用"); 
      %> 
      <tr align="center"> 
        <td><%=index%></td><td><%=className%></td><td><%=beginDate%></td><td><%=endDate%></td><td><%=stateName%></td><td>【<a href="###" rel="external nofollow" rel="external nofollow" rel="external nofollow" onclick="">修改</a>】【<a href="###" rel="external nofollow" rel="external nofollow" rel="external nofollow" onclick="">查看</a>】【<a href="###" rel="external nofollow" rel="external nofollow" rel="external nofollow" onclick="">删除</a>】</td> 
      </tr> 
      <% 
        } 
      %> 
    </table> 
  </body> 
</html>