Java数据库连接池之proxool_动力节点Java学院整理

proxool是一种java数据库连接池技术。sourceforge下的一个开源项目,这个项目提供一个健壮、易用的连接池，最为关键的是这个连接池提供监控的功能，方便易用，便于发现连接泄漏的情况。

目前是和dbcp以及c3p0一起，最为常见的三种jdbc连接池技术。

日前，hibernate官方宣布由于bug太多不再支持dbcp，而推荐使用 proxool或c3p0。

下面通过一个demo说明一下如何使用：

        项目结构如下：

        dblink.java文件中的代码：

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(); 
    } 
  } 
} 

        proxool.xml文件中的代码：

<?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> 

        web.xml文件中的代码：

<?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> 

        index.jsp文件中的代码：

<%@ 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> 

总结

以上所述是小编给大家介绍的java数据库连接池之proxool，希望对大家有所帮助