Java 如果Employee中有另一个对象，如何在JSP中正确保存Employee

员工实体：

@Entity
@Table(name = "EMPLOYEE")
public class Employee {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int id;
@ManyToOne(targetEntity = Department.class)
@JoinColumn(name = "department_id")
private Department department;
@Column(name = "FIRST_NAME")
private String firstName;
@Column(name = "LAST_NAME")
private String lastName;
@Column(name = "SALARY")
private int salary;

EmployeeDao具有两个变量路径来保存员工：

@Override
@Transactional(readOnly = false)
public void addEmployee(int departmentId, String firstName, String lastName, int salary) {
    Department department = getDepartmentById(departmentId);
    Employee employee = new Employee(department, firstName, lastName, salary);
    sessionFactory.getCurrentSession().save(employee);
}

@Override
@Transactional(readOnly = false)
public void addEmployee(Employee employee) {
    sessionFactory.getCurrentSession().save(employee);
}

主控制器：

@RequestMapping(value = "/employee/add", method = RequestMethod.GET)
public ModelAndView addPage(Model model) {
    model.addAttribute("emp", new Employee());
    List<Department> departments = dao.getAllDepartments();
    model.addAttribute("deps", departments);
    return new ModelAndView("Add");
}

@RequestMapping(value = "/employee/add", method = RequestMethod.POST)
public ModelAndView addEmployee(@ModelAttribute("emp") Employee employee) {

    System.out.println(employee);
    //dao.addEmployee(employee);
    return new ModelAndView("redirect:/");
}

---

帮助，请不要传递子id，您可以直接传递带有相应键的对象并保存实体

i、 e.用此标签替换您的选择标签

<select>
    <c:forEach var="dep" items="${deps}">
       <option name="department" value="${dep}"> ${dep.name}</option>
    </c:forEach>
</select>

${dep.name}

或

如果您只想通过传递子对象的主键来实现这一点，那么可以使用带有spring验证器的

@InitBinder

来识别子对象

提及

注意：在rest方法中，您是通过按部门id获取部门来添加员工的，因此工作正常，并且在jsp post请求中，您传递的员工实体只是部门id，而不是部门对象

@RequestMapping(value = "/add/employee/{departmentId}/{firstName}/{lastName}/{salary}", method = RequestMethod.POST, headers = "Accept=application/json")
public void addEmployee(@PathVariable int departmentId,@PathVariable String firstName,@PathVariable String lastName,@PathVariable int salary) {
    dao.addEmployee(departmentId, firstName, lastName, salary);
    dao.calculateAvgSalaryInDepartment();
}

<select>
    <c:forEach var="dep" items="${deps}">
       <option name="department" value="${dep}"> ${dep.name}</option>
    </c:forEach>
</select>