Linzz's blog
Java Web项目实战-五
Linzz
  2017-04-15 22:36:53   2024-10-04 19:27:50    

上次完成了login页面，把表单内容提交到后台servlet，所以现在就来写后台的判断

首先写好好一个User的Java bean，这个我前面已经完成了
然后，因为最近在练习Mybatis的使用，那这里我也用Mybatis

1.mybatis-config.xml完成与数据库的连接

在src文件夹创建mybatis-config.xml文件，内容如下：

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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
    <package name="controller"/>
</typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver"
                    value="com.mysql.jdbc.Driver" />
                <property name="url"
                    value="jdbc:mysql://localhost:3333/article?characterEncoding=UTF-8" />
                <property name="username" value="root" />
                <property name="password" value="mysqladmin" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
    <mapper resource="controller/User.xml"/>
</mappers>
</configuration>

这里有一个很坑很坑的地方，困扰了我好几天。就是

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<typeAliases>
    <package name="controller"/>
</typeAliases>

这一句，package name应该是调用mybatis-config的那个文件所在的包名，当时我把controller打成了别的包名，后面各种调试一直出各种莫名其妙的bug比如什么ClassNotFound，知道了真相之后，我只能说，MMP

好了，题外话

2.Mybatis完成MySQL的CURD操作

然后需要写一个操作数据库的User.xml，如下：

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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd"> 
<mapper namespace="controller">
    <select id="listUser" resultType="User">
        select * from   user      
    </select>
    
    <select id="selectUser"  resultType="User">
       select * from user where username=#{username} and password=#{password}     
    </select>
    
    
    <insert id="addUser" parameterType="User" >
        insert into user ( username ) values (#{username})    
    </insert>
    
     
    <delete id="deleteUser" parameterType="User" >
        delete from user where id= #{id}   
    </delete>
     
    <select id="getUser" parameterType="String" resultType="User">
        select * from   user  where username = #{username}    
    </select>
    
    <select id="getPassword" parameterType="String" resultType="User">
        select password from   user  where username = #{username}    
    </select> 
    <update id="updateUser" parameterType="User" >
        update User set name=#{name} where id=#{id}    
    </update>
</mapper>

在后面，我将使用getPassword这一句，来查询验证密码是否正确

3.LoginServlet

创建servlet，重写doGet方法：

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package controller;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class LoginServlet extends HttpServlet {
/**
 * Constructor of the object.
 */
public LoginServlet() {
    super();
}
/**
 * The doGet method of the servlet. <br>
 *
 * 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 {
    
    String username = request.getParameter("username").trim();
    String password = request.getParameter("password").trim();
        
            
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder()
                    .build(inputStream);
            SqlSession session=sqlSessionFactory.openSession();
             Map<String,Object> params = new HashMap<>();
             params.put("username", username);
                params.put("password", password);
                List<User> us = session.selectList("getPassword",username);
                User user = us.get(0);
                if(user.getPassword().equals(password)){
                    request.getRequestDispatcher("/index.jsp").forward(request,response);
                }
        
        
    }
/**
 * The doPost method of the servlet. <br>
 *
 * 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 {
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
    out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
    out.println("<HTML>");
    out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
    out.println("  <BODY>");
    out.print("    This is ");
    out.print(this.getClass());
    out.println(", using the POST method");
    out.println("  </BODY>");
    out.println("</HTML>");
    out.flush();
    out.close();
}
}

到此后台基本功能就写好了

index.jsp

最后是首页，我把之前C#作业给搬过来了，也是用的bootstrap

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<%@ page language="java" import="java.util.*"  pageEncoding="UTF-8"%>
<%
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%>">
<script language="javascript">
function start(){
you = 100;
devil = 100;
var result = document.getElementById("result");
result.innerHTML="start";
}
function heal(){
rd = Math.floor(Math.random()*30);
var tmp = 0;tmp = you+15;
you = you+15-rd;
    var result = document.getElementById("result");
if(you>0&&devil>0){
result.innerHTML="你使用了一个血瓶，血量变为"+tmp+"<br/>"+"然而大魔王趁你不备发动攻击<br/>现在你的血量变为"+you+" 大魔王血量为"+devil;}
else if(you<0&&devil>0){
result.innerHTML="你输了，哈哈，辣鸡";}
else if(you>0&&devil<0){
result.innerHTML="你赢了，然而并没有什么奖励";}
else{
result.innerHTML="你和大魔王同归于尽了，大家当做无事发生过";
}

}
function attack(){//传入表单参数
rd1 = Math.floor(Math.random()*30);
rd2 = Math.floor(Math.random()*30);
    you = you-rd1;
    devil = devil- rd2;
    var result = document.getElementById("result");
    if(you>0&&devil>0){
    result.innerHTML="你上去就是一拳，大魔王剩下血量为"+devil+"<br/>"+"愤怒的大魔王反击，你剩下的血量为"+you;}
    else if(you<0&&devil>0){
    result.innerHTML="你输了，哈哈，辣鸡";}
    else if(you>0&&devil<0){
    result.innerHTML="你赢了，然而并没有什么奖励";}
    else{
    result.innerHTML="你和大魔王同归于尽了，大家当做无事发生过";
    }
    }
    </script>
    
<title>决斗吧大魔王</title>
<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">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
 <link href="http://libs.baidu.com/bootstrap/3.0.3/css/bootstrap.min.css" rel="stylesheet">
<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
</head>
<body style="background-image:url(https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1491491962000&di=a101e2033883077242ea21ad64dc3444&imgtype=0&src=http%3A%2F%2Fh7.86.cc%2Fwalls%2F20160729%2F1920x1200_88f5b02af13e733.jpg)" >
<div class="container">
<%@include file="./header.jsp" %>
<div class="col-md-6 colum">
<div class="jumbotron">
<h1>拯救地球<br />消灭大魔王</h1>
        <p>
            某一天，你在上课的路上遇到一只扬言要毁灭世界的大魔王
        </p>
        <button class="btn btn-primary btn-large" onClick="start()"  >开始</button>
        <br/>
        <button class="btn btn-primary btn-large" onClick="attack()" >攻击</button>
        <button class="btn btn-primary btn-large" onClick="heal()" >回血</button>
        <br/>
        <span id="result">
        
        </span>
</div>
</div>
</div>
<br>
</body>
</html>

其中header.jsp

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<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
        <div class="col-md-12 column" >
            <ul class="nav nav-tabs">
                <li style="font-size:20px;">
                     <a href="index.jsp">首页</a>
                </li>
                <li style="font-size:20px;">
                     <a href="login.jsp">登陆</a>
                </li>
                <li style="font-size:20px;">
                     <a href="#">商店</a>
                </li>
                
        </ul>
    </div>
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