使用LayUi+Servlet+JDBC开发员工管理

﹏ヽ暗。殇╰゛Y 2024-04-06 10:50 41阅读 0赞

#### 文章目录 ####

*  前言
 *  一、准备工作
 *  二、编写代码
 *   *  1.登陆实现

--------------------

## 前言 ##

本篇主要讲述，一个员工管理模块的开发

--------------------

## 一、准备工作 ##

首先需要准备数据库文件，我们需要两张表，一张员工表employee，一张部门表department。员工和部门是多对一的关系，即，多个员工对应一个部门。一个员工只有一个部门。  
字段设计如下：  
employee  
![在这里插入图片描述][837ef8b8483642879414eeb0d5915db3.png]apartment  
![在这里插入图片描述][4f3ef3935e8943399eae94aedf4f41f8.png]两个表之间，通过部门编号dept\_no实现外键关联。  
然后创建web项目，结构如下：  
![在这里插入图片描述][2a5eeb9b22844362ae79513e461ec2e3.png]  
导入相关jar包和静态资源。  
![在这里插入图片描述][93c08753648c42c5a9ae6e2ff666b5a0.png]  
导入layui包

## 二、编写代码 ##

### 1.登陆实现 ###

此处我直接在网上找了一个登陆页面。  
大概是下图这样：  
![在这里插入图片描述][34ee54d603c545c69e44f6eea1adb49a.png]

> 首先编写页面的验证处理

//登陆
    var JsonData = {
        
    		username: uname,
    		password: pwd
    	};
    	$.post("login?method=loginVerify",JsonData,function(res) {
        
    		$d = JSON.parse(res);
    		if($d.code == 0){
        
    			layer.msg($d.msg, {
        
    				icon: 1,
    				time: 1000 //1秒关闭（如果不配置，默认是3秒）
    			}, function(){
        
    				window.sessionStorage.setItem('username',uname);
    				window.location.href='managePage/index.html';
    			});
    		}else{
        
    			layer.msg($d.msg,{
        
    				icon: 2,
    				time: 1000 //2秒关闭（如果不配置，默认是3秒）
    			});
    		}
    	});

编写后端Servlet方法，接收Ajax的异步请求

@WebServlet("/login")
    public class LoginServlet extends BaseServlet {
        
        private LoginServiceImpl service =  new LoginServiceImpl();
    
    
        public void loginVerify(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
            //接收数据，进行判断是否登陆成功！
            HttpSession session = req.getSession();
            String username =  req.getParameter("username");
            String password = req.getParameter("password");
            int key = service.verifyLogin(username,password);
            //设置输出流
            PrintWriter out = resp.getWriter();
            if (key > 0){
        //登陆成功
                //设置session值
                session.setAttribute("loginFlag",true);
                out.write(Result.toClient(0,"登陆成功！"));
            }else {
        
                out.write(Result.toClient(1,"登陆失败，用户名或密码错误！"));
            }
            //关流
            out.flush();
            out.close();
        }
        public void loginOut(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
    
            HttpSession session = req.getSession();
            //销毁登陆状态
            session.invalidate();
        }
    }

编写service业务层接口，编写处理servlet调用的方法

package com.lzl.service;
    
    /**
     * --效率，是成功的核心关键--
     * --自负，会让每个人都屈膝下跪--
     *
     * @Author lzl
     * @Date 2022/9/12 09:59
     */
    
    public interface LoginService {
        
        /**
         *@Description 业务层登陆验证
         *@Param username,password
         *@Return 受影响行数
         */
        Integer verifyLogin(String username,String password);
    }

编写业务实现类

/**
     * --效率，是成功的核心关键--
     * --自负，会让每个人都屈膝下跪--
     *
     * @Author lzl
     * @Date 2022/9/12 10:01
     */
    
    public class LoginServiceImpl implements LoginService {
        
        private UserDao impl = new UserDaoImpl();
        /**
         * @param username
         * @param password
         * @Description 业务层登陆验证
         * @Param username, password
         * @Return 受影响行数
         */
        @Override
        public Integer verifyLogin(String username, String password) {
        
            return impl.getLogin(username,password);
        }
    }

编写Dao接口，及其实现方法

package com.lzl.dao;
    
    public interface UserDao {
        
        int getLogin(String username, String password);
    }

public class UserDaoImpl implements UserDao {
        
        //获得连接
        private Connection conn = null;
        //预编译处理对象
        private PreparedStatement pst = null;
        //结果集
        private ResultSet rts = null;
        @Override
        public int getLogin(String username, String password) {
        
            int key = 0;
            try {
        
                conn = DBUtil.getConnection();
                String sql  = "select * from user where username = ?";
                pst = conn.prepareStatement(sql);
                pst.setString(1,username);
                rts = pst.executeQuery();
                User user = null;
                if(rts.next()){
        
                    user = new User();
                    user.setUsername(rts.getString("username"));
                    user.setPassword(rts.getString("password"));
                    if (user.getPassword().equals(password)){
        
                        key = 1;
                    }
                }
            } catch (SQLException e) {
        
                e.printStackTrace();
            } finally {
        
                DBUtil.closeAll(rts,pst,conn);
            }
            return key;
        }
      
    }

至此，登陆功能实现完毕！

接下来查询所有员工，首先先编写Daoimpl

//获得连接
        private Connection conn = null;
        //预编译处理对象
        private PreparedStatement pst = null;
        //结果集
        private ResultSet rts = null;
        // 参数集合params
        private ArrayList<Object> params = null;
        /**
         * 获得所有的员工数据
         * @return list员工集合
         */
        @Override
        public List<Employee> getAll(Map<String, Object> keys) {
        
            List<Employee> list = new ArrayList<>();
            // 查询所需参数的集合
            params = new ArrayList<>();
            //设置sql where 1 = 1 确保sql一定可以执行
            String sql = "select e.*,d.dept_name from employee e " +
                    "inner join department d on e.emp_dept_no = d.dept_no where 1 = 1";
            //拼接字符串
            if(!StringUtils.isNull(keys.get("emp_name"))){
        
                sql += " and e.emp_name like ?";
                params.add("%" + keys.get("emp_name") + "%");
            }
            if(!StringUtils.isNull(keys.get("dept_no"))){
        
                sql += " and e.emp_dept_no = ?";
                params.add(keys.get("dept_no"));
            }
            if(!StringUtils.isNull(keys.get("emp_status"))){
        
                sql += " and e.status = ?";
                params.add(keys.get("emp_status"));
            }
            if(!StringUtils.isNull(keys.get("beginTime"))){
        
                sql += " and e.emp_hire_time > ?";
                params.add(keys.get("beginTime"));
            }
            if(!StringUtils.isNull(keys.get("endTime"))){
        
                sql += " and e.emp_hire_time  < ?";
                params.add(keys.get("endTime"));
            }
            sql += " order by emp_no limit ?,?";
            Integer page = (Integer) keys.get("page");
            Integer limit = (Integer) keys.get("limit");
            params.add((page - 1) * limit);
            params.add(limit);
            try {
        
                conn = DBUtil.getConnection();
                pst = conn.prepareStatement(sql);
                // 设置参数
                for (int i = 0; i < params.size(); i++) {
        
                    pst.setObject(i + 1, params.get(i));
                }
                rts = pst.executeQuery();
                while (rts.next()){
        
                    Employee employee = new Employee();
                    employee.setEmp_no(rts.getInt("emp_no"));
                    employee.setEmp_name(rts.getString("emp_name"));
                    employee.setEmp_gender(rts.getString("emp_gender"));
                    employee.setEmp_age(rts.getInt("emp_age"));
                    int emp_dept_no = rts.getInt("emp_dept_no");
                    employee.setEmp_dept_no(emp_dept_no);
                    employee.setEmp_salary(rts.getDouble("emp_salary"));
                    employee.setEmp_hire_time(rts.getString("emp_hire_time"));
                    employee.setEmp_position(rts.getString("emp_position"));
                    employee.setEmp_status(rts.getInt("emp_status"));
                    String dept_name = rts.getString("dept_name");
                    Department department = new Department(emp_dept_no,dept_name);
                    employee.setDepartment(department);
                    list.add(employee);
                }
            } catch (SQLException e) {
        
                e.printStackTrace();
            } finally {
        
                DBUtil.closeAll(rts,pst,conn);
            }
            return list;
        }

编写service层方法

private EmployeeDao dao = new EmployeeDaoImpl();
        /**
         * 获得所有的员工
         *
         * @return 符合前端解析的json数据 code，msg，count，data
         */
        @Override
        public ResultLayUi<Employee> getAllEmployee(Map<String, Object> keys) {
        
            List<Employee> list = dao.getAll(keys);
            int count = dao.getCount(keys);
            ResultLayUi<Employee> resultLayUi = new ResultLayUi<>();
            if (list.size() > 0){
        
               resultLayUi.setCode(0);
               resultLayUi.setMsg("查询成功！");
               resultLayUi.setCount(count);
               resultLayUi.setData(list);
            }else {
        
                resultLayUi.setCode(1);
                resultLayUi.setMsg("没有数据！");
            }
            return resultLayUi;
        }

编写servlet层

private EmployeeService service = new EmployeeServiceImpl();
    
        /**
         * 获得所有数据
         * @param req
         * @param resp
         * @throws ServletException
         * @throws IOException
         */
        public void getAll(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
            //多条件查询要传参
            Map<String, Object> keys = new HashMap<>();
            //设置分页
            Integer page = req.getParameter("page") == null ? 1 : Integer.parseInt(req.getParameter("page"));
            Integer limit = req.getParameter("limit") == null ? 10 : Integer.parseInt(req.getParameter("limit"));
            keys.put("page", page);
            keys.put("limit", limit);
            String emp_name = req.getParameter("emp_name");
            String dept_no = req.getParameter("dept_no");
            String emp_position = req.getParameter("emp_position");
            String emp_status = req.getParameter("emp_status");
            String beginTime = req.getParameter("begin");
            String endTime = req.getParameter("end");
            //装进容器
            keys.put("emp_name",emp_name);
            keys.put("dept_no",dept_no);
            keys.put("emp_position",emp_position);
            keys.put("emp_status",emp_status);
            keys.put("beginTime",beginTime);
            keys.put("endTime",endTime);
            //设置输出流
            PrintWriter out = resp.getWriter();
            //获得数据
            ResultLayUi<Employee> layUi = service.getAllEmployee(keys);
            //向页面输出
            out.write(Result.toClient(
                    layUi.getCode(),layUi.getMsg(),
                    layUi.getCount(),layUi.getData()));
            out.flush();
            out.close();
        }

编写前端

至此查询所有和多条件查询已经完成  
最后贴一张完成的效果图

![在这里插入图片描述][eef662b2b26441f6aeb12b82df7ee762.png]

[837ef8b8483642879414eeb0d5915db3.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/06/27a2765daa2b4a769a4551b457178ce2.png
[4f3ef3935e8943399eae94aedf4f41f8.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/06/f29d24e3d3ae40a4a58737ec86d6bf92.png
[2a5eeb9b22844362ae79513e461ec2e3.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/06/dfb8dc097390404b94d6d20f3a283589.png
[93c08753648c42c5a9ae6e2ff666b5a0.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/06/ae6ed19e56d741a5a1af1a3a6e160d7c.png
[34ee54d603c545c69e44f6eea1adb49a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/06/df070d1808e64a85b37fd836660fd4f5.png
[eef662b2b26441f6aeb12b82df7ee762.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/06/9e0c0224f41d4768927accd95a66cf5c.png