Question

好吧，我试图在Spring中使用RestTemplate来使用REST Web服务。该服务返回一个JSON，其中包含对象列表，如下所示。

[
  {
    "name": "123",
    "ids": {
      "y": 36.41666667,
      "x": 39.58333333,
      "z": 12
    },
    "ip": "10.219.90.12",
    "rate": 67.5,
    "id": 1
  },
  {
    "name": "123",
    "ids": {
      "y": 72.5,
      "x": 15.16666667,
      "z": 12
    },
    "ip": "10.219.90.13",
    "rate": 67.5,
    "aarid": 2
  },
  {
    "name": "123",
    "ids": {
      "y": 0,
      "x": 14.33333333,
      "z": 12
    },
    "ip": "10.219.90.14",
    "rate": 67.5,
    "id": 3
  }]

我为此JSON定义了如下POJO。

public class Data {

    @JsonProperty("name")
    private String name;
    @JsonProperty("ip")
    private String ip;
    @JsonProperty("rate")
    private Double rate;
    @JsonProperty("id")
    private Long id;
    @JsonProperty("ids")
    private Ids ids;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getIp() {
        return ip;
    }
    public void setIp(String ip) {
        this.ip = ip;
    }
    public Double getRate() {
        return rate;
    }
    public void setRate(Double rate) {
        this.rate = rate;
    }
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public Ids getIds() {
        return ids;
    }
    public void setIds(Ids ids) {
        this.ids = ids;
    }
}


public class Ids {

    private Double x;

    private Double y;

    private Double z;

    public void setX(Double x) {
        this.x = x;
    }

    public void setY(Double y) {
        this.y = y;
    }

    public void setZ(Double z) {
        this.z = z;
    }

    public Double getX() {
        return x;
    }

    public Double getY() {
        return y;
    }

    public Double getZ() {
        return z;
    }

    @Override
    public String toString() {
        return "AARPosition [x=" + x + ", y=" + y + ", z=" + z + "]";
    }

}

我尝试使用以下代码来使用该服务：

ResponseEntity<List<Data>> responseEntity = aarRestClient.exchange("http://123.11.25.333/v1/data",
                HttpMethod.GET, null, new ParameterizedTypeReference<List<Data>>() {    });

我将null传递给上面的实体，即使我创建实体并尝试，也会出现相同的结果。

HttpHeaders headers = new HttpHeaders();
        headers.setAccept(Arrays.asList(MediaType.APPLICATION_OCTET_STREAM));

        HttpEntity<String> entity = new HttpEntity<String>("parameters", headers);

ResponseEntity<List<Data>> responseEntity = aarRestClient.exchange("http://123.11.25.333/v1/data",
                HttpMethod.GET, entity , new ParameterizedTypeReference<List<Data>>() { });

我也试过 -

ResponseEntity<Data[]> responseEntity = aarRestClient.getForEntity("http://123.11.25.333:42317/v1/data", Data[].class);

但是，没有运气。在所有情况下我都低于例外。

org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class [Lcom.zebra.ala.rtlsclient.Data;] and content type [application/octet-stream]
    at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:109) ~[spring-web-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:835) ~[spring-web-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:819) ~[spring-web-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:599) ~[spring-web-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:557) ~[spring-web-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:289) ~[spring-web-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at com.zebra.ala.rtlsclient.AARHealthHandler.monitorAARHealth(AARHealthHandler.java:38) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_92]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_92]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_92]

可以请任何人帮助我！提前谢谢。

Answer 1

它无法使用默认MappingJackson2HttpMessageConverter，因为您的服务器会将不合适的Content-Type作为application/octet-stream返回，其中MappingJackson2HttpMessageConverter仅支持：

public MappingJackson2HttpMessageConverter(ObjectMapper objectMapper) {
    super(objectMapper, MediaType.APPLICATION_JSON, new MediaType("application", "*+json"));
}

您可以通过setSupportedMediaTypes(List<MediaType> supportedMediaTypes)通过自定义提供您自己的转换器实例，但可能最好说服服务器端返回正确的JSON内容类型......

无法提取响应：找不到合适的HttpMessageConverter用于响应

1 个答案: