Question

POST请求正文json值：

{
    "id" : 452312313231,
    "name" : "b2",
    "floor": 5
}

建筑类代码：

@Entity
@Table(name = "building")
public class Building implements Serializable{

    private static final long serialVersionUID = -3009157732242241606L;
    @Id
    @Column(name = "building_ID")
    @NotNull
    @Digits(fraction = 0, integer = 15)
    private long id;

    @Column(name = "NAME")
    @NotNull
    private String name;

    @Column(name = "floor")
    @NotNull
    @Digits(fraction = 0, integer = 2)
    private int floor;
    public Building() {}
    public Building(long id, String name, int floor) {

        this.id = id;
        this.name = name;
        this.floor = floor;
    }

控制器代码：

@RequestMapping(value = "/building", method = RequestMethod.POST, headers = "Accept=application/json")
    @ResponseBody
    String post(Model model, @Valid @ModelAttribute("Building") Building building, BindingResult result) {
        if (result.hasErrors()) {
            System.out.println("Wrong data");
            return "Null values or worng data please check properly Number = " + result.getErrorCount() + " \n Error : "
                    + result.getAllErrors();
        } else {

            buildingRep.save(building);
            return "Succesfull";
        }
    }

使用jpa保存数据。我通过@RequestBody选择@ModelAttribute以便于验证。问题是构建对象总是空的。我在用json对象做任何事情吗？

Answer 1

@ModelAttribute 是一个注释，它将方法参数或方法返回值绑定到命名的模型属性，然后将其公开给Web视图。对于 @RequestBody ，绑定到Web请求标头并包含DTO。

因此，您可以使用 @RequestHeade 来代替 @Valid @ModelAttribute（＆＃34; Building＆＃34; ），它应该有效。

使用@ModelAttribute对象的Spring为空

1 个答案: