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Tomcat中数据库连接池如何设置与应用

发布时间:2022-01-11 14:05:08 所属栏目:MySql教程 来源:互联网
导读:这篇文章主要介绍了Tomcat中数据库连接池如何设置与应用,具有一定借鉴价值,感兴趣的朋友可以参考下,希望大家阅读完这篇文章之后大有收获,下面让小编带着大家一起了解一下。 配置:Tomcat5.5+JEE(jsdk1.5)+WINXP 还是简单的说一说文件配置: 1:修改%tomca
      这篇文章主要介绍了Tomcat中数据库连接池如何设置与应用,具有一定借鉴价值,感兴趣的朋友可以参考下,希望大家阅读完这篇文章之后大有收获,下面让小编带着大家一起了解一下。
 
配置:Tomcat5.5+JEE(jsdk1.5)+WINXP
 
      还是简单的说一说文件配置:
1:修改%tomcat%/conf/server.xml在
 
后加如下内容.
     <Resource
name="jdbc/DBPool" //数据源名称
     type="javax.sql.DataSource"
     password="xxxxxxxx"
     driverClassName="com.mysql.jdbc.Driver"
     maxIdle="2"
     maxWait="5000"
     username="root"
     url="jdbc:mysql://127.0.0.1:3306/hptest"
     maxActive="4"/>
2.修改%tomcat%/conf/context.xm;在后加
  <ResourceLink
name="jdbc/DBPool"
  type="javax.sql.DataSource"
  global="jdbc/DBPool"/>
3.修改%tomcat%/conf/web.xml
 
   MySQL DB Connection Pool
   jdbc/DBPool
   javax.sql.DataSource
   Container
   Shareable
 
 这样配置就算差不多了.如果具体的还不懂可见上次发的文章.
4.写一个程序测试.(写一个WEB程序)
  我的是Myeclipse 写的程序,这里不能从电脑上贴图真有点不方便(我想哭).
    1:写一个连接类:    
 DBPool.java
package com.test;
 
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;
 
public class DBPool {
   private static DataSource pool;
   static {
        Context env = null;
         try {
             env = (Context) new InitialContext().lookup("java:comp/env");
             pool = (DataSource)env.lookup("jdbc/DBPool");
             if(pool==null)
                 System.err.println("'DBPool' is an unknown DataSource");
              } catch(NamingException ne) {
                 ne.printStackTrace();
         }
     }
   public static DataSource getPool() {
       return pool;
   }
 
}
   2:写一个Servlet:  
 其中有是用来连接数据库和显示查询结果.
 Mytest.java
 package com.test;
 
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
public class Mytest extends HttpServlet {
 
   /**
    * Constructor of the object.
    */
   public Mytest() {
       super();
   }
 
   /**
    * Destruction of the servlet.
 
    */
   public void destroy() {
       super.destroy(); // Just puts "destroy" string in log
       // Put your code here
   }
 
   /**
    * The doGet method of the servlet.
 
    *
    * This method is called when a form has its tag value method equals to get.
    *
    * @param request the request send by the client to the server
    * @param response the response send by the server to the client
    * @throws ServletException if an error occurred
    * @throws IOException if an error occurred
    */
   public void doGet(HttpServletRequest request, HttpServletResponse response)
           throws ServletException, IOException {
 
       response.setContentType("text/html;charset=gb2312");
       PrintWriter out = response.getWriter();
       String id=(String)request.getParameter("id");
       Connection con=null;
       try{
           
           con=DBPool.getPool().getConnection();
            Statement stmt=con.createStatement();
               ResultSet rst=stmt.executeQuery("select * from userinf where userid='"+id+"'");
                 if(rst.next()){
                                         out.println("
ID号:"+rst.getInt("userid"));
                     out.println("
用户名:"+com.test.ASSICTOGBR2312.trans(rst.getString("name")));
                     out.println("
地址:"+rst.getString("address" ));
                     out.println("
生日"+rst.getDate("year" ));
                 }
                 else{
                 out.println("没有这个ID");
                 stmt.close();
                 }
       }
       catch(Exception e){
           e.printStackTrace();
       }
       finally{  //一定要注意这里对数据库的关闭不然
                            //自己想了
           try{
               if(con!=null){
                   con.close();
               }
               
           }
         catch(Exception e){
          e.printStackTrace();
         
      }
           
       }
   
   }
 
   /**
    * The doPost method of the servlet.
 
    *
    * This method is called when a form has its tag value method equals to post.
    *
    * @param request the request send by the client to the server
    * @param response the response send by the server to the client
    * @throws ServletException if an error occurred
    * @throws IOException if an error occurred
    */
   public void doPost(HttpServletRequest request, HttpServletResponse response)
           throws ServletException, IOException {
       doGet(request,response);
       
   }
 
   /**
    * Initialization of the servlet.
 
    *
    * @throws ServletException if an error occure
    */
   public void init() throws ServletException {
       // Put your code here
   }
 
}
     3:写一个JSP页面:
        Myjsp.jsp
   
<%@ page="" language="java" import="java.util.*" pageencoding="gb2312">
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
 
  
   
   <!--
   
   -->
  
 
   This is my JSP page.
 
   
 
   print input search id:
 
   
   
 
 
 
  4:其中有转字,为了不显示乱码
   package com.test;
 
import java.io.*;
public class ASSICTOGBR2312 {
     public static String trans(String ass){
         String res=null;
         byte temp[];
         try{
             temp=ass.getBytes("iso-8859-1");
             res=new String(temp);
         }
         catch(UnsupportedEncodingException en) {
             System.out.println(en.toString());
         }
         
       
         
         return res;
   
     }
}
 
 
  5:web.xml
 
 
<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">
 
   This is the description of my J2EE component
   This is the display name of my J2EE component
   Mytest
   com.test.Mytest
 
 
 
   Mytest
   /servlet/Mytest
 
 
 
 
  6: 其中数据库结构如下:
     数据库名:hptest
     表:userinf
     用下面的命令建一个数据库和表
     create database hptest;
     create table  userinf (
      userid int(4) not null,
      name char(10) not null,
      address varchar(50),
      year date,
      constraint fk_userinf primary key(userid));
      )
      insert into userinf values(19,'hp','cq','1982-10-22');
感谢你能够认真阅读完这篇文章,希望小编分享的“Tomcat中数据库连接池如何设置与应用”这篇文章对大家有帮助。

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