javaweb的一个小dome，一个小项目。

B站黑马程序员javaweb教程实践，可以登录，注册（有验证码），连接数据库后可以查看数据（到自己的手里记得改数据库的东西）。运用Mapper，Mybatis,Maven,Mysql,VUE,ajax等。页面写的不行，可以自己更改。

废话不多说，先上效果图。

这里的验证码可以自己生成。验证码的‘看不清’可以自动生成（不是自己放进去的图片资源）

1. 一进系统就直接访问后台信息（什么系统可以自己改）
   
2. 修改页面
   
3. 删除页面
   
4. 批量删除
   
5. 新增页面
   
6. 查询页面
   

代码展示

1. …\src\main\java\com\swzl\web\old\CheckCodeServlet.java

与验证码有关

package com.swzl.web.old;

import com.swzl.util.CheckCodeUtil;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;

@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        // 生成验证码
        ServletOutputStream os = response.getOutputStream();
        String checkCode = CheckCodeUtil.outputVerifyImage(100, 50, os, 4);
        // 存入Session
        HttpSession session = request.getSession();
        session.setAttribute("checkCodeGen",checkCode);
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
        this.doGet(request, response);
    }
}

2. …/src\main\java\com\swzl\web\old\LoginServlet.java

package com.swzl.web.old;

import com.swzl.pojo.User;
import com.swzl.service.UserService1;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    private UserService1 service = new UserService1();
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.接受用户名和密码
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        //复选框
        String remember = request.getParameter("remember");

        //2.调用service完成查询
        User user = service.login(username, password);

        //3.判断user是否为null
        if(user!=null){
            //登陆成功,跳转查询全部

            //判断用户是否勾选记住框
            if ("1".equals(remember)){
                //勾选了
                //1.创建cookie对象
                Cookie c_username = new Cookie("username", username);
                Cookie c_password = new Cookie("password", password);
                //设置cookie存活时间
                c_username.setMaxAge(60*60*24*7);
                c_password.setMaxAge(60*60*24*7);
                //2.发送cookie
                response.addCookie(c_username);
                response.addCookie(c_password);
            }

            //将登陆成功的user对象，存储到session
            HttpSession session = request.getSession();
            session.setAttribute("user",user);

            String contextPath = request.getContextPath();
            response.sendRedirect(contextPath + "/find.html");
        }else{
            //登陆失败
            //存储错误信息到request
            request.setAttribute("login_msg","用户名或密码错误");
            //跳转到login.jsp
            request.getRequestDispatcher("/login.jsp").forward(request,response);
        }
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }
}

3. …\src\main\java\com\swzl\web\old\RegisterServlet.java

package com.swzl.web.old;

import com.swzl.pojo.User;
import com.swzl.service.UserService1;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;

@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {
    private final UserService1 service = new UserService1();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1. 获取用户名和密码数据
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        User user = new User();
        user.setUsername(username);
        user.setPassword(password);

        // 获取用户输入的验证码
        String checkCode = request.getParameter("checkCode");
        // 程序生成的验证码，从Session获取
        HttpSession session = request.getSession();
        String checkCodeGen = (String) session.getAttribute("checkCodeGen");
        // 比对
        if(!checkCodeGen.equalsIgnoreCase(checkCode)){
            request.setAttribute("register_msg","验证码错误");
            request.getRequestDispatcher("/register.jsp").forward(request,response);
            // 不允许注册
            return;
        }



        //2. 调用service 注册
        boolean flag = service.register(user);
        //3. 判断注册成功与否
        if(flag){
            //注册功能，跳转登陆页面

            request.setAttribute("register_msg","注册成功，请登录");
            request.getRequestDispatcher("/login.jsp").forward(request,response);
        }else {
            //注册失败，跳转到注册页面

            request.setAttribute("register_msg","用户名已存在");
            request.getRequestDispatcher("/register.jsp").forward(request,response);
        }


    }

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

文件夹

运行所用

插件

Maven和Tomcat自己下载吧

源码下载链接：https://download.csdn.net/download/weixin_46991478/86223334（虽然也不是什么好东西，只是dome罢了）