<a class="btn btn-sm btn-primary" th:href="@{/update/} + ${emp.id} ">修改</a>

//修改

@GetMapping("/update/{id}")

public String updataEmp(@PathVariable("id")Integer id,

                        Model model){

    Employee employee = employeeDao.get(id);

    model.addAttribute("emp",employee);

    //部门选择的修改

    Collection<Department> departments = departmentDao.getDepartments();

    model.addAttribute("depts",departments);

    return "emp/update";

}

<form th:action="@{/update1}" method="post">

   <!--发送put请求修改员工数据-->

   <!--

   、SpringMVC中配置HiddenHttpMethodFilter;（SpringBoot自动配置好的）

   、页面创建一个post表单

   、创建一个input项，name="_method";值就是我们指定的请求方式

   -->

   <input type="hidden" name="_method" value="put" th:if="${emp!=null}"/>

   <!-- id -->

   <input type="hidden" name="id" th:if="${emp!=null}" th:value="${emp.id}">

   <div class="form-group">

      <label>LastName</label>

      <input name="lastName" type="text" class="form-control" 
placeholder="zhangsan" th:value="${emp!=null}?${emp.lastName}">

   </div>

   <div class="form-group">

      <label>Email</label>

      <input name="email" type="email" class="form-control" 
placeholder="zhangsan@atguigu.com" th:value="${emp!=null}?${emp.email}">

   </div>

   <div class="form-group">

      <label>Gender</label><br/>

      <div class="form-check form-check-inline">

         <input class="form-check-input" type="radio" 
name="gender" value="" th:checked="${emp!=null}?${emp.gender==1}">

         <label class="form-check-label">男</label>

      </div>

      <div class="form-check form-check-inline">

         <input class="form-check-input" type="radio" name="gender" value="" th:checked="${emp!=null}?${emp.gender==0}">

         <label class="form-check-label">女</label>

      </div>

   </div>

   <div class="form-group">

      <label>department</label>

      <!--提交的是部门的id-->

      <select class="form-control" name="department.id">

         <option th:each="dept:${depts}" th:text="${dept.departmentName}"

         th:selected="${dept.id == emp.department.id}"  th:value="${dept.id}"></option>

      </select>

   </div>

   <div class="form-group">

      <label>Birth</label>

      <input name="birth" type="text" class="form-control" 
placeholder="zhangsan" th:value="${emp!=null}?${#dates.format(emp.birth, 'yyyy-MM-dd HH:mm')}">

   </div>

   <button type="submit" class="btn btn-primary" th:text="${emp!=null}?'修改':'添加'">添加</button>

</form>

//员工修改

@PutMapping("/update1")

public String  updataToEmp(Employee employee){

    System.out.println(employee);

    //修改的数据

    employeeDao.save(employee);

    return "redirect:/emps";

}

<form th:action="@{/delete/}+${emp.id}" method="post">

   <input type="hidden" name="_method" value="delete">

   <button class="btn btn-sm btn-danger">删除</button>

</form>

//删除请求

@DeleteMapping("/delete/{id}")

public  String  delete(@PathVariable("id") Integer id){

    employeeDao.delete(id);

    return "redirect:/emps";

}