Question

使用Spring Boot RESTful API应用程序。它有一个动态表单构建组件，我的事件模型可以对问题进行任意回答。我希望能够在一个POST中提交所有内容。这是有效的，除非用户在答案JSON中提供了无效的问题ID。

POST /events看起来像这样：

{
  "eventTemplate": "http://localhost:8090/eventTemplates/1",
  "answers": [
    {"question": "http://localhost:8090/questions/1", "value": "Yes" },
  ],
  "location": "The Moon",
  "observer": "http://localhost:8090/users/1",
  "subject": "http://localhost:8090/users/1",
  "timestamp": "2018-03-19T13:26:44.108Z"
}

如果我将“问题”更改为http://localhost:8090/questions/17，则该问题不存在。我想要一个404.但我不明白。我明白了：

{
  "cause": {
   "cause": {
  "cause": null,
  "message": null
},
"message": "N/A\n at [Source: org.apache.catalina.connector.CoyoteInputStream@7751c231; line: 4, column: 18] (through reference chain: edu.harvard.h2ms.domain.core.Event[\"answers\"]->java.util.HashSet[0]->edu.harvard.h2ms.domain.core.Answer[\"question\"])"},
"message": "JSON parse error: null; nested exception is com.fasterxml.jackson.databind.JsonMappingException: N/A\n at [Source: org.apache.catalina.connector.CoyoteInputStream@7751c231; line: 4, column: 18] (through reference chain: edu.harvard.h2ms.domain.core.Event[\"answers\"]->java.util.HashSet[0]->edu.harvard.h2ms.domain.core.Answer[\"question\"])"
}

事件实体：

@Entity
public class Event {

    @OneToMany(fetch = FetchType.EAGER,
        cascade = CascadeType.ALL,
        mappedBy = "event")
    private Set<Answer> answers = new HashSet<>();

}

回答实体：

@Entity
public class Answer {
  @ManyToOne(fetch = FetchType.EAGEr, cascade = CascadeType.ALL)
  @JoinColumn(name = "question_id")
  private Question question;

}

整个代码库位于https://github.com/stbenjam/h2ms/tree/new-event-model。

任何想法我做错了什么？谢谢！

Answer 1

您可以做的最具体的事情是自定义异常：

@ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
    ...
}

@Controller
public class SomeController {
    @RequestMapping.....
    public void handleCall() {
        if (isFound()) {
            // whatever
        }
        else {
            throw new ResourceNotFoundException(); 
        }
    }
}

当然还有其他方法：使用@ControllerAdvice或return new ResponseEntity<>(HttpStatus.NOT_FOUND)。只是谷歌它，它是相当文件记录。希望很有帮助:)）

保存不存在的关联时Spring不返回404

1 个答案: