Question

所以我在java spring中有一个简单的方法，它返回一个类作为ResponseBody：

@RequestMapping(value = "update", method = RequestMethod.PUT)
public @ResponseBody JKResponse update() {
    return new JKResponse();
}

JKResponse类如下：

@JsonAutoDetect(fieldVisibility = JsonAutoDetect.Visibility.ANY, 
                isGetterVisibility = JsonAutoDetect.Visibility.ANY,
                getterVisibility = JsonAutoDetect.Visibility.ANY)
public class JKResponse implements Serializable {
    static final long serialVersionUID = 1L;

    @JsonProperty
    private List<String> stuff;

    public JKResponse() {
        this.stuff = new ArrayList<String>();
    }

    public void setStuff(final List<String> stuff) {
        this.stuff = stuff;
    }

    public List<String> getStuff() {
        return this.stuff;
    }

    /*
       THIS METHOD IS CAUSING THE INFINITE RECURSION, BUT WHY?
    */
    public ResponseEntity<JResponse> getResponseEntity() {
        return new ResponseEntity<JResponse>(this, HttpStatus.OK);
    }
}

但是当我使用邮递员调用“更新”API路由时，我收到以下错误：

Failed to write HTTP message: org.springframework.http.converter.HttpMessageNotWritableException: Could not write content: Infinite recursion (StackOverflowError) (through reference chain: org.springframework.http.ResponseEntity["body"]->com.proj.services.JKService["responseEntity"]->org.springframework.http.ResponseEntity["body"] and so on...

邮递员中显示的JSON是：

{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body":{"responseEntity":{"headers":{},"body": and so on...

我无法弄清楚造成这种情况的原因，以及为什么会这样。有什么建议吗？

Answer 1

您通常不需要向用户发送ResponseEntity，ResponseEntity是您用来告诉Spring应该返回给用户的数据对象。它应该像这样使用：

@RequestMapping(value = "update", method = RequestMethod.PUT)
public ResponseEntity<JKResponse> update () {
    HttpHeaders responseHeaders = new HttpHeaders();
    responseHeaders.set("Boiling", "True");
    return new ResponseEntity<JKResponse>(
            new JKResponse(), responseHeaders, HttpStatus.I_AM_A_TEAPOT);
}

用户将得到这个：

$ curl -X PUT -i 127.0.0.1:8080/update
HTTP/1.1 418 
Server: Apache-Coyote/1.1
Boiling: True
Content-Type: application/json;charset=UTF-8
Transfer-Encoding: chunked
Date: Tue, 29 Dec 2015 20:03:51 GMT

{"stuff":[]}

Java Spring - 如何修复HttpMessageNotWritableException无限递归JSON响应？

1 个答案: