java在未知属性上的PUT和POST失败会引发不同的行为

Question

我正在使用Spring数据Rest存储库编写Spring引导应用程序，如果请求体包含具有未知属性的JSON，我想拒绝对资源的访问。简化实体和存储库的定义：

@Entity
public class Person{
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;

    private String firstName;
    private String lastName;

    /* getters and setters */
}

@RepositoryRestResource(collectionResourceRel = "people", path = "people")
public interface PersonRepository extends CrudRepository<Person, Long> {}

我使用Jackson的反序列化功能来禁止JSON中的未知属性

@Bean 
public Jackson2ObjectMapperBuilder objectMapperBuilder(){
    Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
    builder.failOnUnknownProperties(true);
    return builder;
}

当我发送POST请求时，一切正常。当我使用有效字段时，我会得到正确的响应：

curl -i -x POST -H "Content-Type:application/json" -d '{"firstName": "Frodo", "lastName": "Baggins"}' http://localhost:8080/people
{
  "firstName": "Frodo",
  "lastName": "Baggins",
  "_links": {...}
}

当我发送带有未知字段的JSON时，应用程序会抛出预期错误：

curl -i -x POST -H "Content-Type:application/json" -d '{"unknown": "POST value", "firstName": "Frodo", "lastName": "Baggins"}' http://localhost:8080/people
com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "unknown" (class Person), not marked as ignorable (2 known properties: "lastName", "firstName")

使用有效JSON时，PUT方法也会返回正确的响应。然而，当我发送带有未知字段的PUT请求时，我希望Spring会抛出错误，但相反，Spring会更新数据库中的对象并返回它：

curl -i -x PUT -H "Content-Type:application/json" -d '{"unknown": "PUT value", "firstName": "Bilbo", "lastName": "Baggins"}' http://localhost:8080/people/1
{
  "firstName": "Bilbo",
  "lastName": "Baggins",
  "_links": {...}
}

只有在数据库中没有具有给定id的对象时才会引发错误：

curl -i -x PUT -H "Content-Type:application/json" -d '{"unknown": "PUT value", "firstName": "Gandalf", "lastName": "Baggins"}' http://localhost:8080/people/100
com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "unknown" (class Person), not marked as ignorable (2 known properties: "lastName", "firstName")

这是预期行为还是Spring数据Rest中的错误当具有未知属性的JSON被传递到应用程序时，无论请求方法是什么，我如何抛出错误

我通过修改http://spring.io/guides/gs/accessing-data-rest/复制了这种行为，我所做的唯一更改是Jackson2ObjectMapperBuilder，此项目中没有其他控制器或存储库