一、项目介绍
无双飞单机器人管理系统下载项目地址：https://www.taiyiliao.com/
本项目是基于JavaWeb工程的用户管理系统，编写的目的在于更好的学习JavaWeb，博客最后附上项目的地址，欢迎大家下载。
二、项目功能介绍
1、登陆页面

使用了bootstrap.css来优化页面，使用session来存储用户的账号和密码

2、注册页面

与登陆页面相似，也使用了bootstrap.css，注册成功替换原先的cookie值

3、用户信息列表页面

从数据库中获取数据，并显示在页面中，并实现了分页加载技术

@WebServlet(urlPatterns = “/pageQueryServlet”)
public class PageQueryServlet extends HttpServlet {br/>@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);br/>}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String strPageNum = request.getParameter(“pageNum”);
String strPageSize = request.getParameter(“pageSize”);
UserService userService = new UserService();
//当前页的页数
int pageNum = Integer.parseInt(strPageNum);
//每页显示的个数
int pageSize = Integer.parseInt(strPageSize);
//每页的起始条目索引
int startCount = (pageNum - 1) * pageSize;
List pageUsers = userService.pageQuery(startCount, pageSize);

int totalItemCount = userService.queryTotalItemCount(pageSize);
int totalPageCount;
//计算总页数
if (totalItemCount % pageSize == 0) {
    totalPageCount = totalItemCount % pageSize;
} else {
    totalPageCount = totalItemCount / pageSize + 1;
}

if (pageUsers != null) {
    //查询成功
    request.setAttribute("pageUsers", pageUsers);
    request.setAttribute("pageNum", pageNum);
    request.setAttribute("pageSize", pageSize);
    request.setAttribute("totalPageCount", totalPageCount);
    request.setAttribute("totalItemCount", totalItemCount);
    request.getRequestDispatcher("/list.jsp").forward(request, response);
}

}

}
4、修改联系人页面
实现了数据的回显功能，但是没有做数据的校验，可以使用jQuery Validate的进行表单校验来优化项目

数据回显代码：

@WebServlet(urlPatterns = “/queryUserByIdServlet”)
public class QueryUserByIdServlet extends HttpServlet {br/>@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}

@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//处理修改用户信息之前的查询操作
request.setCharacterEncoding("utf-8");
String id = request.getParameter("id");
//根据ID获取用户信息
UserService userService = new UserService();
User userInfo = userService.queryUserById(id);
String pageNum = request.getParameter("pageNum");
String pageSize = request.getParameter("pageSize");
if (userInfo != null) {
//查询成功
request.setAttribute("user", userInfo);
request.setAttribute("pageNum", pageNum);
request.setAttribute("pageSize", pageSize);
request.getRequestDispatcher("/update.jsp").forward(request, response);
} else {
request.setAttribute("errorMsg", "查询用户信息失败！");
request.getRequestDispatcher("/error.jsp").forward(request, response);
}
}
}
修改数据代码：

@WebServlet(urlPatterns = “/updateUserByIdServlet”)
public class UpdateUserByIdServlet extends HttpServlet {br/>@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}

@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
//获取数据
String id = request.getParameter("id");
String name = request.getParameter("name");
String sex = request.getParameter("sex");
String age = request.getParameter("age");
String address = request.getParameter("address");
String qq = request.getParameter("qq");
String email = request.getParameter("email");
String pageNum = request.getParameter("pageNum");
String pageSize = request.getParameter("pageSize");
//处理数据
User user = new User(Integer.parseInt(id), name, sex, Integer.parseInt(age), address, qq, email);
UserService userService = new UserService();
boolean isUpdate = userService.updateUserById(user);
if (isUpdate) {
//修改成功，查询所有用户信息
response.sendRedirect("/pageQueryServlet?pageNum=" + pageNum + "&pageSize=" + pageSize);
} else {
//修改失败
request.setAttribute("errorMsg", "修改用户信息失败");
request.getRequestDispatcher("/error.jsp").forward(request, response);
}
}

}
5、删除用户功能
@WebServlet(urlPatterns = “/deleteUserByIdServlet”)
public class DeleteUserByIdServlet extends HttpServlet {br/>@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}

@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//设置编码格式
request.setCharacterEncoding("utf-8");
String pageNum = request.getParameter("pageNum");
String pageSize = request.getParameter("pageSize");
//获取数据
String id = request.getParameter("id");
//处理数据
UserService userService = new UserService();
boolean isDelete = userService.deleteUserById(id);
if (isDelete) {
//删除成功，需要查询所有用户信息
response.sendRedirect("/pageQueryServlet?pageNum=" + pageNum + "&pageSize=" + pageSize);
} else {
//删除失败，跳到错误页面
request.setAttribute("errorMsg", "删除用户信息失败");
request.getRequestDispatcher("/error.jsp").forward(request, response);
}
}

}
6、添加用户页面
和修改联系人页面一样，没有做表单校验。

提交代码：

@WebServlet(urlPatterns = “/addUserServlet”)
public class AddUserServlet extends HttpServlet {br/>@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}

@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
//获取数据
String name = request.getParameter("name");
String sex = request.getParameter("sex");
String age = request.getParameter("age");
String address = request.getParameter("address");
String qq = request.getParameter("qq");
String email = request.getParameter("email");
String pageNum = request.getParameter("pageNum");
String pageSize = request.getParameter("pageSize");
//处理数据
User user = new User(null, name, sex, Integer.parseInt(age), address, qq, email);
UserService userService = new UserService();
boolean isAdd = userService.addUser(user);
if (isAdd) {
//添加成功，需要查询所有用户信息
response.sendRedirect("/pageQueryServlet?pageNum=" + pageNum + "&pageSize=" + pageSize);
} else {
//添加失败，跳转失败页面
request.setAttribute("errorMsg", "添加用户信息失败！");
request.getRequestDispatcher("/error.jsp").forward(request, response);
}
}

项目地址：https://www.taiyiliao.com/