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【Servlet+JDBC+HTML+MySQL+】------查询综合案例

分享第二十四篇励志语句

对自己狠一点，逼自己努力，再过五年你将会感谢今天发狠的自己，恨透今天懒惰自卑的自己，既然认准了一条路，那就坚持走下去，命运不会辜负每一个认真而努力的人。

在MySQL中新建一个servletdatabase数据库，专门用来学习servlet操作数据库

1 案例需求

实现登录功能，登录成功后显示所有管理员信息，登录失败给出“账号或密码错误，无法登录”提示信息

2 创建表admin并添加数据

#创建表admin
CREATE TABLE IF NOT EXISTS `admin`(
`username` VARCHAR(20) PRIMARY KEY,
`password` VARCHAR(20) NOT NULL,
`phone` VARCHAR(11) UNIQUE NOT NULL,
`address` VARCHAR(20) NOT NULL
);

#向admin表中插入数据
INSERT INTO `admin`(`username`,`password`,`phone`,`address`)
VALUES('张三','123456','13112345678','安徽合肥蜀山区');

INSERT INTO `admin`(`username`,`password`,`phone`,`address`)
VALUES('李四','123456','13822334455','安徽合肥高新区');

3 创建Web项目

创建Web项目adminProject01，在项目下创建包目录结构如下，并导入相关jar包及配置文件

4 database.properties文件

5 DBUtile类代码

package com.cxyzxc.www.utils;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
import javax.sql.DataSource;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;

public class DBUtils {

    // 声明一个连接池对象
    private static DruidDataSource druidDataSource;

    static {
        // 实例化配置文件对象
        Properties properties = new Properties();

        try {
            // 加载配置文件内容
            InputStream is = DBUtils.class
                    .getResourceAsStream("/database.properties");
            properties.load(is);
            // 创建连接池
            druidDataSource = (DruidDataSource) DruidDataSourceFactory
                    .createDataSource(properties);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //返回一个数据源
    public static DataSource getDataSource(){
        return druidDataSource;
    }

}

6 Admin实体类

package com.cxyzxc.www.entity;

public class Admin {

    private String username;
    private String password;
    private String phone;
    private String address;

    public Admin() {
    }

    public Admin(String username, String password, String phone, String address) {
        this.username = username;
        this.password = password;
        this.phone = phone;
        this.address = address;
    }

    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 getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        return "Admin{" +
                "username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", phone='" + phone + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

7 AdminDao接口

package com.cxyzxc.www.dao;

import com.cxyzxc.www.entity.Admin;

import java.util.List;

public interface AdminDao {

    //查询用户（查询单个）
    Admin selectOneByUsernameAndPassword(String username, String password);

    //查询所有用户
    List<Admin> selectAll();
}

8 AdminDaoImpl实现类

package com.cxyzxc.www.dao.impl;

import com.cxyzxc.www.dao.AdminDao;
import com.cxyzxc.www.entity.Admin;
import com.cxyzxc.www.utils.DBUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

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

public class AdminDaoImpl implements AdminDao {
    // 创建QueryRunner对象，并传递一个数据源对象
    private final QueryRunner QUERYRUNNER = new QueryRunner(DBUtils.getDataSource());

    @Override
    public Admin selectOneByUsernameAndPassword(String username, String password) {
        String sql = "SELECT * FROM `admin` WHERE `username` = ? AND `PASSWORD`=?;";
        Object[] args = {username, password};
        try {
            return QUERYRUNNER.query(sql, new BeanHandler<Admin>(Admin.class), args);
        } catch (SQLException e) {
            e.printStackTrace();

        }

        return null;
    }

    @Override
    public List<Admin> selectAll() {
        String sql = "SELECT * FROM `admin`;";
        try {
            return QUERYRUNNER.query(sql, new BeanListHandler<Admin>(Admin.class));
        } catch (SQLException e) {
            e.printStackTrace();
        }

        return null;
    }

}

9 AdminService接口

package com.cxyzxc.www.service;

import com.cxyzxc.www.entity.Admin;

import java.util.List;

public interface AdminService {

    Admin login(String username, String password);

    List<Admin> selectAllAdmin();
}

10 AdminServiceImpl实现类

package com.cxyzxc.www.service.impl;

import com.cxyzxc.www.service.AdminService;
import com.cxyzxc.www.dao.AdminDao;
import com.cxyzxc.www.dao.impl.AdminDaoImpl;
import com.cxyzxc.www.entity.Admin;

import java.util.List;

public class AdminServiceImpl implements AdminService {
    private final AdminDao ADMINDAO = new AdminDaoImpl();

    @Override
    public Admin login(String username, String password) {
        return ADMINDAO.selectOneByUsernameAndPassword(username, password);
    }

    @Override
    public List<Admin> selectAllAdmin() {
        return ADMINDAO.selectAll();
    }
}

11 HTML页面

11.1 login.html页面

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>登录页面</title>
        <link type="text/css" rel="stylesheet" href="css/login.css"/>
    </head>

    <body>
        <div>
            <form action="LoginServlet" method="post">
                <p>
                    账号：<input type="text" name="username"/>
                </p>
                <p>
                    密码：<input type="password" name="password"/>
                </p>
                <p>
                    <input type="submit" value="登录"/>
                </p>
            </form>
        </div>
    </body>
</html>

11.2 login.css

* {
    margin: 0;
    padding: 0;
}

div {
    width: 400px;
    height: 100px;
    background-color: #ccc;
    margin: 30px auto;
    padding-top: 30px;
    text-align: center;
}

p {
    margin-top: 10px;
}

input {
    outline: none;
}

11.3 table.css

*{
    margin: 0;
    padding: 0;
}

table{
    margin: 20px auto;
    width: 500px;
    height: 100px;
    text-align: center;
}

12 LoginServlet

package com.cxyzxc.www.servlet;

import com.cxyzxc.www.service.AdminService;
import com.cxyzxc.www.service.impl.AdminServiceImpl;
import com.cxyzxc.www.entity.Admin;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private final AdminService ADMINSERVICE = new AdminServiceImpl();

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        req.setCharacterEncoding("UTF-8");
        //获取数据
        String username = req.getParameter("username");
        String password = req.getParameter("password");

        Admin admin = ADMINSERVICE.login(username, password);

        resp.setContentType("text/html;charset=UTF-8");
        PrintWriter printWriter = resp.getWriter();

        if (admin != null) {
            printWriter.println("<html>");
            printWriter.println("<head>");
            printWriter.println("<title>登录成功</title>");
            printWriter.println("</head>");
            printWriter.println("<body>");
            printWriter.println("<h2>登录成功</h2>");
            printWriter.println("</body>");
            printWriter.println("</html>");
        } else {
            printWriter.println("<html>");
            printWriter.println("<head>");
            printWriter.println("<title>登录失败</title>");
            printWriter.println("</head>");
            printWriter.println("<body>");
            printWriter.println("<h2>账号或密码错误，无法登录</h2>");
            printWriter.println("</body>");
            printWriter.println("</html>");

        }

    }

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

13 ShowAllAdminServlet

package com.cxyzxc.www.servlet;

import com.cxyzxc.www.service.AdminService;
import com.cxyzxc.www.service.impl.AdminServiceImpl;
import com.cxyzxc.www.entity.Admin;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

@WebServlet("/ShowAllAdminServlet")
public class ShowAllAdminServlet extends HttpServlet {
    private final AdminService ADMINSERVICE = new AdminServiceImpl();

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        req.setCharacterEncoding("UTF-8");
        resp.setContentType("text/html;charset=UTF-8");

        PrintWriter printWriter = resp.getWriter();
        List<Admin> adminList = ADMINSERVICE.selectAllAdmin();
        if (adminList.size() != 0) {
            printWriter.println("<html>");
            printWriter.println("<head>");
            printWriter.println("<title>所有admin</title>");
            printWriter.println("<link type=\"text/css\" rel=\"stylesheet\" href=\"css/table.css\" />");
            printWriter.println("</head>");
            printWriter.println("<table border='1px' cellspacing='0'>");
            printWriter.println("<tr>");
            printWriter.println("<th>账号</th>");
            printWriter.println("<th>密码</th>");
            printWriter.println("<th>手机号码</th>");
            printWriter.println("<th>住址</th>");
            printWriter.println("<th>操作</th>");
            printWriter.println("</tr>");
            for (Admin admin : adminList) {
                printWriter.println("<tr>");
                printWriter.println("<td>" + admin.getUsername() + "</td>");
                printWriter.println("<td>" + admin.getPassword() + "</td>");
                printWriter.println("<td>" + admin.getPhone() + "</td>");
                printWriter.println("<td>" + admin.getAddress() + "</td>");
                printWriter.println("<td><a href=\"#\">修改</a> <a href=\"#\">删除</a></td>");
                printWriter.println("</tr>");
            }
            printWriter.println("</table>");
            printWriter.println("</html>");
        } else {
            printWriter.println("<html>");
            printWriter.println("<head>");
            printWriter.println("<title>所有admin</title>");
            printWriter.println("</head>");
            printWriter.println("<body>");
            printWriter.println("<h2>当前没有用户</h2>");
            printWriter.println("</body>");
            printWriter.println("</html>");
        }

    }

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

好了，这些就是单独查和全部查的全部方法，感谢大家支持

今天的分享就到此结束了

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标签： java 开发语言
本文转载自: https://blog.csdn.net/swy2560666141/article/details/128465946
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