springboot_数据增删改查

前期数据准备(模拟数据库)

@Repository
public class DepartmentDao {
    //模拟数据库中的数据
    private static Map<Integer, Department> departmentMap = null;
    static {
        departmentMap = new HashMap<>();
        departmentMap.put(101,new Department(101,"教学部"));
        departmentMap.put(102,new Department(102,"市场部"));
        departmentMap.put(103,new Department(103,"教研部"));
        departmentMap.put(104,new Department(104,"运营部"));
        departmentMap.put(105,new Department(105,"后勤部"));
    }
    //获得所有部门信息
    public Collection<Department> getDepartment(){
        return departmentMap.values();
    }
    //通过ID获取部门
    public Department getDepartmentById(Integer id){
        return departmentMap.get(id);
    }
}

@Repository
public class EmployeeDao {

    private static Map<Integer, Employee> employeeMap = null;
    @Autowired
    private DepartmentDao departmentDao;
    static {
        employeeMap = new HashMap<>();
        employeeMap.put(1001,new Employee(1001,"AA","123456AA@qq.com",1,new Department(101,"教学部")));
        employeeMap.put(1002,new Employee(1002,"BB","123456BB@qq.com",0,new Department(102,"市场部")));
        employeeMap.put(1003,new Employee(1003,"CC","123456CC@qq.com",1,new Department(103,"教研部")));
        employeeMap.put(1004,new Employee(1004,"DD","123456DD@qq.com",0,new Department(104,"运营部")));
        employeeMap.put(1005,new Employee(1005,"EE","123456EE@qq.com",1,new Department(105,"后勤部")));
    }
    //主键自增
    private static Integer initId = 1;
    //增加操作
    public void add(Employee employee){
        if (employee.getId() == null){
            employee.setId(initId++);
        }
        employee.setDepartment(departmentDao.getDepartmentById(employee.getDepartment().getId()));
        employeeMap.put(employee.getId(),employee);
    }
    //查询全部员工
    public Collection<Employee> getAllEmployee(){
        return employeeMap.values();
    }
    //按id查询信息
    public Employee getEmployeeById(Integer id){
        return employeeMap.get(id);
    }
    //通过id删除员工
    public void deleteEmployeeById(Integer id){
        employeeMap.remove(id);
    }
}

1、员工列表展示(查)

• thymeleaf提取公共页面
  • 提取：th:fragment="sidebar"
  • 插入：<div th:replace="~{commons/commons::sidebar}"></div>
    或者<div th:insert="~{commons/commons::sidebar}"></div>
  • 如果传递参数：使用():
    <div th:insert="~{commons/commons::sidebar(active='main.html')}"></div>
  • 接收判断：
    <a th:class="${active=='main.html'?'nav-link active':'nav-link'}" th:href="@{/index.html}">
• 列表循环展示
  • Controller返回前端数据:

    @Controller
    public class EmployeeController {
        @Autowired
        EmployeeDao employeeDao;
    
        @RequestMapping("/emps")
        public String list(Model model){
            Collection<Employee> employees = employeeDao.getAllEmployee();
            model.addAttribute("emps",employees);
            return "emp/list";
        }
    }
    

  • 遍历循环：

    <tr th:each="emp:${emps}">
        <td th:text="${emp.getId()}"></td>
        <td th:text="${emp.getLastName()}"></td>
        <td th:text="${emp.getEmail()}"></td>
        <td th:text="${emp.getGender()==0?'女':'男'}"></td>
        <td th:text="${emp.getDepartment().getDepartmentName()}"></td>
        <td th:text="${#dates.format(emp.getBirth(),'yyyy-MM-dd HH:mm:ss')}"></td>
    </tr>
    

2、添加员工(增)

• 提交按钮

  <!-- 设置action，进入对应的controller  请求方法：post -->
  <form th:action="@{/emp}" method="post">
  

  //进入@PostMapping的controller
  @PostMapping("/emp")
  public String addEmp(Employee employee){
      System.out.println(employee);
      employeeDao.add(employee);
      return "redirect:/emps";
  }
  

• 跳转到添加页面

  <!-- 点击添加添加员工，进行页面跳转 -->
  <h2><a class="btn btn-sm btn-success" th:href="emp">添加员工</a></h2>
  

  //对应的controller，@GetMapping,此controller进行页面的跳转
  //model设置departments参数返回前端显示
  @GetMapping("/emp")
  public String toAddPage(Model model){
      Collection<Department> department = departmentDao.getDepartment();
      model.addAttribute("departments",department);
      return "emp/add";
  }
  

    <!-- 前端遍历departments进行显示 -->
    <select class="form-control" name="department.id">
        <option th:each="dept:${departments}" th:text="${dept.getDepartmentName()}" th:value="${dept.getId()}"></option>
    </select>
  

• 添加员工成功
• 返回首页

  @PostMapping("/emp")
      public String addEmp(Employee employee){
          System.out.println(employee);
          employeeDao.add(employee);
          //重定向到员工信息页面，
          return "redirect:/emps";
      }
  

  //跳转到对应这，返回list页面。
  @RequestMapping("/emps")
  public String list(Model model){
  Collection<Employee> employees = employeeDao.getAllEmployee();
  model.addAttribute("emps",employees);
  return "emp/list";
  }
  

3、员工修改信息(改)

• 编辑按钮

  <!-- 添加id参数，以便于修改页面显示对应的信息-->
  <!-- http://localhost:8080/emp/1001 -->
  <a class="btn btn-sm btn-primary" th:href="@{/emp/}+${emp.getId()}">编辑</a>
  

• 跳转页面controller

  //去员工的修改页面
      @GetMapping("/emp/{id}")
      public String toUpdatePage(@PathVariable("id")Integer id,Model model){
          //查出原来的数据
          Employee employee = employeeDao.getEmployeeById(id);
          model.addAttribute("employee",employee);
          //查询所有部门的信息
          Collection<Department> department = departmentDao.getDepartment();
          model.addAttribute("departments",department);
          return "emp/update";
      }
  

• 添加隐藏域，防止在用户展示页面会自增长

  <!--添加隐藏域-->
  <input type="hidden" name="id" th:value="${employee.getId()}">
  

• 修改成功，跳转页面

  <form th:action="@{/empUpdate}" method="post"></form>
  

  //去员工的修改页面
  @PostMapping("/empUpdate")
  public String updateEmp(Employee employee){
      employeeDao.add(employee);
      return "redirect:/emps";
  }
  

4、删除信息(删)

• 删除的标签

  <a class="btn btn-sm btn-danger" th:href="@{/delEmp/}+${emp.getId()}">删除</a>
  

• 跳转的controller

  //删除员工
  @GetMapping("/delEmp/{id}")
  public String deleteEmp(@PathVariable("id")Integer id){
      employeeDao.deleteEmployeeById(id);
      return "redirect:/emps";
  }
  

5、注销

• 前端

  <a class="nav-link" th:href="@{/user/logout}">注销</a>
  

• controller

  @RequestMapping("/user/logout")
  public String logout(HttpSession session){
      session.invalidate();
      return "redirect:/index.html";
  }