简单的Javaweb项目（mvc模式，数据库用MySQL）jsp+MySQL+servlet

最新推荐文章于 2021-02-19 12:00:47 发布

原创最新推荐文章于 2021-02-19 12:00:47 发布 · 4.8k 阅读

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CC 4.0 BY-SA版权

文章标签：

#javaweb #mvc

本文介绍了一个使用JSP和Servlet实现的用户信息管理系统，涵盖了数据库建立、实体类设计、服务类实现及JSP页面展示等关键步骤。

关键在于引入MySQL的驱动包，还有引入在jsp中用到的jstl包，流程如下：

1.建立数据库

CREATE TABLE `userinfo` (
`id` int(255) NOT NULL auto_increment,
`name` varchar(20) default NULL,
`age` varchar(4) default NULL,
`city` varchar(20) default NULL,
`remark` varchar(25) default NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=20 DEFAULT CHARSET=utf8;

2.建立web项目

**如果不会配置serlvet那么可以选择Java EE version2.5以前的版本，2.5以前的版本自动配置servlet**

3.在src文件夹下建立com包和servlet包，引入MySQL的驱动包

****引入MySQL的驱动包*******vv

4.创建数据库连接类 DBUtils.java（建立在com包中）

package com;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class DBUtils {

   String user ="root";
   String password ="123456";
   Connection conn = null;
   private static final String URI = "jdbc:mysql://localhost:3333/test" ;

   public Connection getCon() throws SQLException{
       try {
           Class.forName("com.mysql.jdbc.Driver");

           conn=DriverManager.getConnection(URI,user,password);
           return conn ;
       } catch (ClassNotFoundException e) {
           System.out.println("驱动加载错误");
           e.printStackTrace();
       }
       return null ;
   }
}

String password="123456"；是我数据库的密码，根据你们数据库的密码自行设定

private static final String URI = "jdbc:mysql://localhost:3333/test" ； 3333是我数据库的端口号，可根据你们数据库的端口号而定“test”是我的数据库的名字，可根据自己数据库的名字填写

5.建立实体类 UserInfo.java（建立在com包中）

package com;

public class UserInfo {

   private int id;
   private String name;
   private String age;
   private String city;
   private String remark;

   public UserInfo(String name, String age, String city, String remark) {
       super();
       this.name = name;
       this.age = age;
       this.city = city;
       this.remark = remark;
   }

   public UserInfo(int id, String name, String city) {
       super();
       this.id = id;
       this.name = name;
       this.city = city;
   }

   public UserInfo(int id, String name, String age, String city, String remark) {
       super();
       this.id = id;
       this.name = name;
       this.age = age;
       this.city = city;
       this.remark = remark;
   }

   @Override
   public String toString() {
       String msg = "id=" + id
               + " ,name = " + name
               + ",age = " + age
               + ",city = " + city
               + ",remark = " + remark;
       System.out.println(msg);
       return msg;
   }

   public int getId() {
       return id;
   }

   public void setId(int id) {
       this.id = id;
   }

   public String getName() {
       return name;
   }

   public void setName(String name) {
       this.name = name;
   }

   public String getAge() {
       return age;
   }

   public void setAge(String age) {
       this.age = age;
   }

   public String getCity() {
       return city;
   }

   public void setCity(String city) {
       this.city = city;
   }

   public String getRemark() {
       return remark;
   }

   public void setRemark(String remark) {
       this.remark = remark;
   }

}

6.建立一个接受服务的类（UserInfoService.java）建立在com包中

package com;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import com.mysql.jdbc.PreparedStatement;
import com.DBUtils;
import com.UserInfo;
public class UserInfoService extends DBUtils{

   Connection conn = null ;

   public UserInfoService() throws SQLException{
       conn = getCon() ;
   }


   public boolean add(UserInfo u){
       PreparedStatement ps = null;
       boolean flag = false ;
       try {
           String sql = "insert into userinfo(name,age,city,remark) values ('"
                   + u.getName()+"',"
                   + u.getAge()+",'"
                   + u.getCity()+"','"
                   + u.getRemark()
                   + "')" ;
           System.out.println(sql);
           ps = (PreparedStatement) conn.prepareStatement(sql);
           ps.execute();
           flag = true ;
           System.out.println("注册结果:"+flag);
       } catch (Exception e) {
           e.printStackTrace();
       }
       return flag ;
   }


   public List<UserInfo> list(UserInfo u){
       PreparedStatement ps = null;
       List<UserInfo> list = new ArrayList<UserInfo>();
       UserInfo userInfo = null;
       try {
           String name = u.getName();
           String city = u.getCity();
           int id = u.getId();

           String sql = "select * from userinfo where 1=1 ";
           if(id != 0 ){
               sql = sql + " and id ="+id ;
           }
           if(name != null && !name.isEmpty()){
               sql = sql + " and name like '%"+name+"%'" ;
           }
           if(city != null && !city.isEmpty() ){
               sql = sql + " and city ='"+city+"'" ;
           }
           System.out.println(sql);
           ps = (PreparedStatement) conn.prepareStatement(sql);
           ResultSet rs= ps.executeQuery();
           while (rs.next()) {
               userInfo = new UserInfo(rs.getString("name"),
                       String.valueOf(rs.getInt("age")),
                       rs.getString("city"),
                       rs.getString("remark"));
               userInfo.setId(rs.getInt("id"));
               list.add(userInfo);
           }
       } catch (Exception e) {
           e.printStackTrace();
       }
       return list ;
   }



   public void deleteuserInfo(int id) throws SQLException {
       String sql = "DELETE FROM userinfo WHERE id = ?" ;
       System.out.println("删除userinfo");
       PreparedStatement pst = (PreparedStatement) conn.prepareStatement(sql) ;
       pst.setInt(1, id);
       pst.executeUpdate();
   }


/*   public UserInfo findUserById(int id) throws SQLException{
       String sql = "select * from userinfo where id = ?" ;
       PreparedStatement pst = (PreparedStatement) conn.prepareStatement(sql) ;
       pst.setInt(1, id);
       ResultSet rs =pst.executeQuery();
       UserInfo userInfo = null ;
       while (rs.next()) {
           userInfo = new UserInfo(rs.getString("name"),
                   String.valueOf(rs.getInt("age")),
                   rs.getString("city"),
                   rs.getString("remark"));
           userInfo.setId(id);
       }
       return userInfo ;
   }

   */
}

7.注意在WebRoot文件夹的子文件夹WEB-INF中引入MySQL驱动包，不然页面会报错；同时也引入jstl的jar包

8.在servlet包中建立servlet

注册的servlet：

package servlet;

import java.io.IOException;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.UserInfo;
import com.UserInfoService;

public class AddUserServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public AddUserServlet() {
super();
// TODO Auto-generated constructor stub
}

   /**
   * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
   */
   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       request.setCharacterEncoding("utf-8");
       String name = request.getParameter("name");
       String age = request.getParameter("age");
       String city = request.getParameter("city");
       String remark = request.getParameter("remark");
       UserInfo userinfo = new UserInfo(name, age, city, remark);
       userinfo.toString();
       boolean result = false ;
       try {
           UserInfoService us = new UserInfoService();
           result = us.add(userinfo);
       } catch (SQLException e) {
           e.printStackTrace();
       }
       if(result){
           System.out.println("add userinfo success .");
           response.sendRedirect("QueryUserInfoServlet");
       }else{
           response.sendRedirect("error.jsp");
       }

       //request.getRequestDispatcher("QueryUserInfoServlet").forward(request, response);
   }

   /**
   * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
   */
   protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       doGet(request, response);
   }

}

删除用户的servlet：

package servlet;

import java.io.IOException;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.UserInfoService;

/**
* Servlet implementation class DeleteUserInfoServelt
*/
public class DeleteUserInfoServelt extends HttpServlet {
private static final long serialVersionUID = 1L;

public DeleteUserInfoServelt() {
super();

}

   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {


       String idStr = request.getParameter("id") ;
           try {
               UserInfoService u = new UserInfoService();
               int id = Integer.valueOf(idStr);
               u.deleteuserInfo(id);
               System.out.println("删除成功！");
           } catch (SQLException e) {
               e.printStackTrace();
               System.out.println("删除失败！");
           }

           response.sendRedirect("QueryUserInfoServlet");
   }

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

}

在jsp页面显示注册用户的servlet：

package servlet;

import java.io.IOException;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.UserInfo;
import com.UserInfoService;

public class QueryUserInfoServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

public QueryUserInfoServlet() {
super();

}

   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       request.setCharacterEncoding("utf-8");
       int id = 0;

       String idStr = request.getParameter("id") ;
       if(idStr !=null && !idStr.isEmpty()){
           id = Integer.valueOf(request.getParameter("id"));
       }
       String name = request.getParameter("name");
       String city = request.getParameter("city");
       if("0".equals(city)){
           city = null ;
       }
       UserInfo userinfo = new UserInfo(id,name,city);
       userinfo.toString();
       List<UserInfo> list = null ;
       try {
           UserInfoService us = new UserInfoService();
           list = us.list(userinfo);
       } catch (SQLException e) {
           e.printStackTrace();
       }

       request.setAttribute("list", list);
       request.getRequestDispatcher("userlist.jsp").forward(request, response);
   }

   protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

       doGet(request, response);
   }

}

8.建立jsp页面：

userAdd.jsp

<%@page contentType="text/html;charset=utf-8"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>注册用户</title>
</head>
<body>
   <form name="form1" method="post" action="AddUserServlet">
       <table border="0" align="center">

           <tr>
               <td>姓名</td>
               <td><input name="name" type="text" id="birthday"></td>
           </tr>
           <tr>
               <td>年龄</td>
               <td><input name="age" type="text" id="age"></td>
           </tr>

userlist.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
   pageEncoding="UTF-8"%>
<%@ page import="java.util.*"%>
<%@ page import="com.*"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!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=UTF-8">
<title>Insert title here</title>
</head>
<%
   List<UserInfo> list = (List) request.getAttribute("list");
%>
<body>
   
   <form action="QueryUserInfoServlet" method="post">
       编号: <input id="id" name="id" type="text" /><br> 姓名：<input
           id="name" name="name" type="text" /><br> 城市：<select id="city"
           name="city" style="width: 152px">
           <option value="0">全部</option>
           <option value="1">南宁</option>
           <option value="2">桂林</option>
           <option value="3">柳州</option>
       </select><br> <input type="submit" value="查询" /> <input type="reset"
           value="重置" /> <a href="userAdd.jsp">注册</a>
   </form>
   ------------------------------------------------
   
   <table>
       <tr>
           <td>编号</td>
           <td>姓名</td>
           <td>所在城市</td>
           <td>年龄</td>
           <td>备注</td>
           <td colspan="1" align="right">操作</td>
       </tr>
       <c:forEach items="${list}" var="userinfo">
           <tr>
               <td>${userinfo.id}</td>
               <td>${userinfo.name}</td>
               <td>${userinfo.city}</td>
               <td>${userinfo.age}</td>
               <td>${userinfo.remark}</td>

               <td><a href="DeleteUserInfoServelt?id=${userinfo.id}" >删除</a></td>
           </tr>
       </c:forEach>
   </table>
</body>
</html>

error.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>Insert title here</title>
</head>
<body>
注册失败
</body>
</html>

运行截图：