JavaWeb (五) Jsp+Servlet+MYSQL實現簡單的增刪改查

項目結構目錄：

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

項目環境:

IDEA

JDK 1.8

Tomcat 9

Mysql5.7

MysqlWorkBench 6.3

 

數據庫相關配置如下：

 

create table t_user
(
    uid int(10) not null auto_increment,
    uname varchar(100) not null,
    pwd varchar(100) not null,
    primary key(uid)
    );

 

 

 

 

源代碼：

負責與數據庫交互DAO層

package web.dao;


import web.entity.Admin;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

/**
 *adminDao.java
 * 直接和數據庫交互
 */
public class adminDao {
    public List<Admin> getAllAdmin(){
        List<Admin> list = new ArrayList<>();
        Connection conn = Dbhelper.getConnection();
        String sql ="select * from t_user";
        try {

            PreparedStatement pst = conn.prepareStatement(sql);
            ResultSet rs = pst.executeQuery();
            while(rs.next())
            {
                Admin admin = new Admin();
                admin.setUid(rs.getInt("uid"));
                admin.setUname(rs.getString("uname"));
                admin.setPwd(rs.getString("pwd"));
                list.add(admin);
            }
            rs.close();
            pst.close();
        }catch (Exception e)
        {
            e.printStackTrace();
        }
        return  list;
    }

    public  boolean addAdmin(Admin admin)
    {
        String sql = "insert into t_user(uid,uname,pwd) values(default ,?,?)";
        Connection connection = Dbhelper.getConnection();
        try{
            PreparedStatement pst = connection.prepareStatement(sql);
            pst.setString(1,admin.getUname());
            pst.setString(2,admin.getPwd());
            int count = pst.executeUpdate();
            pst.close();
            return count>0?true:false;
        }catch (Exception e){
            e.printStackTrace();
        }
        return  false;
    }

    public boolean updateAdmin(Admin admin)
    {
        String sql = "update t_user set uname=?,pwd=? where id=?";
        Connection connection = Dbhelper.getConnection();
        try{
            PreparedStatement pst = connection.prepareStatement(sql);
            pst.setString(1,admin.getUname());
            pst.setString(2,admin.getPwd());
            pst.setInt(3,admin.getUid());
            int count = pst.executeUpdate();
            pst.close();
            return count>0?true:false;
        }catch (Exception e)
        {
            e.printStackTrace();
        }
        return false;
    }

    public boolean deleteAdmin(int uid)
    {
        String sql = "delete from t_user where uid = ?";
        Connection connection = Dbhelper.getConnection();
        try {
            PreparedStatement pst = connection.prepareStatement(sql);
            pst.setInt(1,uid);
            int count = 0;
            count = pst.executeUpdate();
            pst.close();
            return  count>0?true:false;
        }catch (Exception e)
        {
            e.printStackTrace();
        }
        return  false;
    }

    public Admin selectAdminByUid(int uid)
    {
        Connection connection = Dbhelper.getConnection();
        String sql = "select * from t_user where uid = "+ uid;
        Admin admin =null;
        try {
            PreparedStatement pst = connection.prepareStatement(sql);
           ResultSet resultSet = pst.executeQuery();
           while (resultSet.next())
           {
               admin= new Admin();
               admin.setUname(resultSet.getString("uname"));
               admin.setUid(resultSet.getInt("uid"));
               admin.setPwd(resultSet.getString("pwd"));
           }
           resultSet.close();
           pst.close();
        }catch (Exception e)
        {
            e.printStackTrace();
        }
        return  admin;
    }


}

package web.dao;

import java.sql.Connection;
import java.sql.DriverManager;

/**
 *Dbhelper.java 
 * 連接數據庫
 */
public class Dbhelper {
    private static String URL = "jdbc:mysql://localhost:3306/roombase"; // 數據庫地址
    private static String userName = "root";
    private static String passWord = "zxc2505004";
    private static String DRIVER = "com.mysql.jdbc.Driver";

    private static Connection conn = null;

    public Dbhelper() {
    }

    /**
     *  獲取連接
     * @return
     */
    public static Connection getConnection()
    {
        if(null == conn){
            try {
                Class.forName(DRIVER);
                conn = DriverManager.getConnection(URL,userName,passWord);
            }catch (Exception e)
            {
                e.printStackTrace();
            }
        }
        return conn;
    }

    /**
     *測試數據庫是否聯通
     * @param args
     */
    public void main(String []args)
    {
        System.err.println(getConnection());
    }


}

ENTITY層：

package web.entity;

import java.io.Serializable;

public class Admin implements Serializable {
    private static final long serialVersinID = 1L;
    private int uid;
    private String uname;
    private String pwd;

    public static long getSerialVersinID() {
        return serialVersinID;
    }

    public int getUid() {
        return uid;
    }

    public void setUid(int uid) {
        this.uid = uid;
    }

    public String getUname() {
        return uname;
    }

    public void setUname(String uname) {
        this.uname = uname;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    @Override
    public String toString() {
        return "Admin{" +
                "uid=" + uid +
                ", uname='" + uname + '\'' +
                ", pwd='" + pwd + '\'' +
                '}';
    }
}

Controller層：

package web.web.servlet;

import web.dao.adminDao;
import web.entity.Admin;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 請求控制層
 *AddServlet.java
 */
public class AddServlet extends HttpServlet {

        private  static  final  long serialVersionUID = 1L;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String uname = req.getParameter("uname");
        String pwd = req.getParameter("pwd");
        Admin admin = new Admin();
        admin.setUname(new String(uname.getBytes("ISO-8859-1"),"UTF-8"));
        admin.setPwd(new String(pwd.getBytes("ISO-8859-1"),"UTF-8"));
        adminDao dao = new adminDao();
        dao.addAdmin(admin);
        req.getRequestDispatcher("ShowServlet").forward(req,resp);//內部重定向
    }

}

package web.web.servlet;

import web.dao.adminDao;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * deleteServlet.java
 */
public class deleteServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String idStr = req.getParameter("uid");
        if(idStr!=null&&!idStr.equals(""))
        {
            int id = Integer.valueOf(idStr);
            adminDao dao = new adminDao();
            dao.deleteAdmin(id);
        }
        req.getRequestDispatcher("ShowServlet").forward(req,resp);
    }
}

package web.web.servlet;

import web.dao.adminDao;
import web.entity.Admin;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

/**
 * ShowServlet.java
 */
public class ShowServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        adminDao dao = new adminDao();
        List<Admin> list = dao.getAllAdmin();
        req.setAttribute("list", list);
        req.getRequestDispatcher("index.jsp").forward(req, resp);
    }

}

package web.web.servlet;

import web.dao.adminDao;
import web.entity.Admin;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * UpdateServlet.JAVA
 */

public class UpdateServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       String idStr = req.getParameter("uid");
        if (idStr != null && !idStr.equals("")) {
            int id = Integer.valueOf(idStr);
            adminDao dao = new adminDao();
            Admin admin = dao.selectAdminByUid(id);
            req.setAttribute("admin", admin);
        }
        req.getRequestDispatcher("update.jsp").forward(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String uname = req.getParameter("uname");
        String pwd = req.getParameter("pwd");
        String idStr = req.getParameter("uid");
        Admin admin = new Admin();
        admin.setUid(Integer.valueOf(idStr));
        admin.setUname(new String(uname.getBytes("ISO-8859-1"),"UTF-8"));
        admin.setPwd(new String(pwd.getBytes("ISO-8859-1"),"UTF-8"));
        adminDao dao = new adminDao();
        dao.updateAdmin(admin);
        req.getRequestDispatcher("ShowServlet").forward(req, resp);

    }
}

JSP頁面:

add.jsp

<%--
  Created by IntelliJ IDEA.
  User: ZHENGZHIQIANG
  Date: 2019/3/2
  Time: 16:14
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>ADD</title>
</head>
<body>
<form action="AddServlet" method="post">
    <table border="1" >
        <tr>
            <td colspan="2"><h1>Add Administrator</h1></td>
        </tr>
        <tr>
            <td>Add Account number </td>
            <td><input type="text" name="uname"/></td>
        </tr>
        <tr>
            <td>Administrator Password</td>
            <td><input type="password" name="pwd"/></td>

        </tr>
        <tr>
            <td colspan="2">
                <input type="submit" value="Submint">
                <input type="reset" value="Flush">
            </td>
        </tr>
    </table>
</form>
</body>
</html>

 

index.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%--
  Created by IntelliJ IDEA.
  User: ZHENGZHIQIANG
  Date: 2019/3/2
  Time: 9:59
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>Show</title>
  <style type="text/css">
    table {
      border: 1px solid pink;
      margin: 0 auto;
    td{
      width: 150px;
      border: 1px solid pink;
      text-align: center;
    }
  </style>
  </head>
  <body>
<table>
  <tr>
    <td>NUMBER</td>
    <td>ACCOUNT NUMBER</td>
    <td>PASSWORD</td>
    <td>OPERATER</td>
  </tr>
  <c:forEach items="${list}" var="item">
    <tr>
      <td>${item.uid}</td>
      <td>${item.uname}</td>
      <td>${item.pwd}</td>
      <td><a href="DeleteServlet?uid=${item.uid}">DELETE</a>-----<a href="UpdateServlet?uid=${item.uid}">EDIT</a> </td>
    </tr>
  </c:forEach>
  <tr>
    <td colspan="2" style="text-align: left"><a href="add.jsp">ADD administrator</a> </td>
  </tr>
</table>

  </body>
</html>

 

update.jsp

<%--
  Created by IntelliJ IDEA.
  User: ZHENGZHIQIANG
  Date: 2019/3/2
  Time: 16:34
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Edit</title>
</head>
<body>
<form action="UpdateServlet" method="post" style="align-items: center">
    <table border="1" >
        <tr>
            <td colspan="2"><h1>Edit administrator info</h1></td>
        </tr>
        <tr>
            <td>uid</td>
            <td><input type="text" name="uid" value="${admin.uid}" readonly="readonly"/></td>
        </tr>
        <tr>
            <td>uname</td>
            <td><input type="text" name="uid" value="${admin.uname}" /></td>
        </tr>
        <tr>
            <td>pwd</td>
            <td><input type="text" name="uid" value="${admin.pwd}" /></td>
        </tr>

        <tr>
            <td colspan="2">
                <input type="submit" value="Submit"/>
                <input type="button" value="Back" onclick="history.go(-1)"/>
           </td>

        </tr>
    </table>

</form>
</body>
</html>

XML配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <display-name>WebBasic</display-name>
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

    <servlet>
        <servlet-name>AddServlet</servlet-name>
        <servlet-class>web.web.servlet.AddServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>AddServlet</servlet-name>
        <url-pattern>/AddServlet</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>DeleteServlet</servlet-name>
        <servlet-class>web.web.servlet.deleteServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>DeleteServlet</servlet-name>
        <url-pattern>/DeleteServlet</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>UpdateServlet</servlet-name>
        <servlet-class>web.web.servlet.UpdateServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>UpdateServlet</servlet-name>
        <url-pattern>/UpdateServlet</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>ShowServlet</servlet-name>
        <servlet-class>web.web.servlet.ShowServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>ShowServlet</servlet-name>
        <url-pattern>/ShowServlet</url-pattern>
    </servlet-mapping>


</web-app>

源代碼如下：