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一个简单的servlet注册试验的一些问题（写不到数据库,望高手指点)

yxc — Thu, 02 Apr 2009 12:16:00 GMT

程序实现目标:写到数据库即可
目录结构:

UserBean.java

package com.study.bean;

public class UserBean {

    private String username;
    private String password;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }



}

UserDao.java

package com.study.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import com.study.bean.*;
import com.study.db.DBHelper;

public class UserDao {
    /**
     *
     * 增加用户
     *
     */

    public void setUser(UserBean tuser)
    {
        String sql = "INSERT INTO T_USER VALUES(null,?,?)";// USER_NAME=?,USER_PWD=?;
        PreparedStatement pstat = null;
        Connection conn = new DBHelper().getConn();
        try {
            pstat = conn.prepareStatement(sql);

            pstat.setString(1, tuser.getUsername());
            pstat.setString(2, tuser.getPassword());


        } catch (SQLException e) {
            // TODO Auto-generated catch block

        } finally {
            try {
                if (conn != null)
                    conn.close();
                if (pstat != null)
                    pstat.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

    }
}

DBHelper.java

package com.study.db;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
/**
*
* 数据库连接类
*
*/
public class DBHelper {
    private String driver = "org.gjt.mm.mysql.Driver";
    private String url = "jdbc:mysql://localhost:3306/first";
    private String user = "root";
    private String pwd = "0433gygy";

    public Connection getConn(){
        Connection conn = null;
        try {
            Class.forName(driver);
            conn = DriverManager.getConnection(url, user, pwd);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return conn;
    }
    public static void main(String[] args) {
        System.out.println("DBHelper.main()" + new DBHelper().getConn());
    }
}

package com.study.servlet;

import javax.servlet.http.*;
import javax.servlet.*;

import java.io.*;

import com.study.bean.*;
import com.study.dao.*;

public class Register extends HttpServlet{
    public void doGet(HttpServletRequest request,HttpServletResponse response)
    throws ServletException,IOException
    {
        String un = request.getParameter("username");
        String pd = request.getParameter("password");


        UserBean Tuser = new UserBean();
        Tuser.setPassword(pd);
        Tuser.setUsername(un);
//        PrintWriter out = response.getWriter();
//        out.println("");
//        out.println(""+Tuser.getUsername()+"");
//        out.println("");
        UserDao dao = new UserDao();
        dao.setUser(Tuser);

    }

     public void doPost(HttpServletRequest request, HttpServletResponse response)
     throws ServletException, IOException
   {
       doGet(request, response);

   }
}

web.xml

<servlet>
    <servlet-name>firstservlet-name>
    <servlet-class>com.study.servlet.Registerservlet-class>
  servlet>
  <servlet-mapping>
    <servlet-name>firstservlet-name>
    <url-pattern>/firsturl-pattern>

  servlet-mapping>

reg.jsp

<body>
    <form action="first" method = "post">
    username:<input type="text" name="username">
    password:<input type="password" name="password">
    <input type="submit" >
    form>
  body>

在reg.jsp 自己随便提交个表单.
程序很简单,没什么东西,结果就是写不到数据库,整个程序运行没有报错!望高手指点一下哪边有问题了.

yxc 2009-04-02 20:16 发表评论

一个关于java的题目,望高手指导一下

yxc — Mon, 22 Sep 2008 16:41:00 GMT

Given:
When //do Stuff is reached,how many objects are eligible for GC.

class CardBoard{
     Short story = 5;
     CardBoard go(CardBoard cb){
            cb = null;
            return cb;
          }

public static void main(String[] args){
    CardBoard c1 = new CardBoard();
    CardBoard c2 = new CardBoard();
    CardBoard c3 = c1.go(c2);
    c1=null;
    //do Stuff
   }
}

高手帮解释一下,谢谢了.

yxc 2008-09-23 00:41 发表评论

关于html标签 textarea

yxc — Mon, 30 Jun 2008 17:38:00 GMT

第一次用，玩一下！

<body>
    <textarea rows="6" cols="30">

<%
    int t=1;
    for(int i=0;i<4;i++)
    {
       for(int j=0;j<=i;j++)
          out.print(t);
       out.println();

    }
%>

    textarea>

  body>

输出：
1
11
111
1111

yxc 2008-07-01 01:38 发表评论

求助，Myeclipse + struts2 + Hibernate + Mysql 的web系统

yxc — Tue, 20 May 2008 06:35:00 GMT

谁能发一个这样的系统给我，只要实现，登陆注册，还有适当的管理功能，比如网上图书管理系统，银行管理系统之类的。
我的邮箱是yxc0433@126.com 不胜感激。

yxc 2008-05-20 14:35 发表评论

实现一个简单的struts2应用（实现登陆）

yxc — Wed, 14 May 2008 17:12:00 GMT

今天我用myeclipse做了一个关于struts2的小例子，和大家分享当然工程新建和服务器配置就不多说了！导入stuts2 的 jar包也不多说了！
首先配置web-inf下的web.xml

xml version="1.0" encoding="UTF-8"?>
<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">
<filter>
<filter-name>struts2filter-name>
<filter-class>org.apache.struts2.dispatcher.FilterDispatcherfilter-class>
filter>
<filter-mapping>
<filter-name>struts2filter-name>
<url-pattern>/*url-pattern>
filter-mapping>
web-app>

右击src建立并配置struts.xml

xml version="1.0" encoding="UTF-8" ?>
DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
   <package name="struts2"  extends="struts-default">
   <action name="login" class="com.test.action.LoginAction">
   <result name="input">login2.jspresult>
   <result>/result.jspresult>
   <result name="failer">/login2.jspresult>
   action>
   package>

struts>

并在src目录下建立包com.test.action,里面新建一个java类LoginAction.java

/*
*Coryright(c)2008 yxc & njust
*All rights reserved.
*/
package com.test.action;

import com.opensymphony.xwork2.ActionSupport;

public class LoginAction extends ActionSupport{  //此处继承的父类ActionSupport就是struts2的一个典型应用
    private String username;
    private String password;
    public String getUsername()
    {
        return username;
    }
    public void setUsername(String username)
    {
        this.username = username;
    }
    public String getPassword()
    {
        return password;
    }
    public void setPassword(String password)
    {
        this.password = password;
    }
    public String execute() throws Exception
    {
        if("hello".equals(this.getUsername().trim())&&"word".equals(this.getPassword().trim()))
        {
            return "success";
        }
        else
        {
            this.addFieldError("username", "username or password error!!!!");
            return "failer";
        }
    }
    @Override
    public void validate() {    //验证

        if(null==this.getUsername()|| "".equals(this.getUsername().trim()))
        {
            this.addFieldError("username", "username request");
        }
        if(null==this.getPassword()||"".equals(this.getPassword().trim()))
        {
            this.addFieldError("password", "password request");
        }
    }


}

在webroot下建立如下jsp文件，login2.jsp,result.jsp

login2.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s"  uri="/struts-tags" %>
DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title heretitle>
head>
<body>
<s:form  action="login">
<s:textfield name="username" label="username">s:textfield>
<s:password name="password" label="password">s:password>
<s:submit name="submit">s:submit>
s:form>
body>
html>

result.jsp

<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
    <head>
    <base href="<%=basePath%>">
    <title>My JSP 'result.jsp' starting pagetitle>
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">

   head>
   <body>
    username:${requestScope.username}<br>
    password:${requestScope.password}
body>

html>

这样就实现了简单的固定用户登陆，username:hello password:word

实现界面

yxc 2008-05-15 01:12 发表评论