使用rest和spring以及嵌套json

Question

我按照http：//spring.io/guides/gs/consulting-rest/使用rest服务。本教程只提到一个单层JSON文件。但是，我希望解析一个json

Foo: {
 fooz: 'stringdescripoers}
 bar : {
    baz: "something",
    etc: [[1,2],[2,0]]
  },
{another object like bar},
{etc}
}

import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestTemplate;

public class Application {

    public static void main(String args[]) {
        RestTemplate restTemplate = new RestTemplate();
        FeatureCollection collection = restTemplate.getForObject("http://www.trafficlink-online.nl/trafficlinkdata/wegdata/TrajectSensorsNH.GeoJSON", FeatureCollection.class);
        System.out.println("it worked");
    }
}

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

@JsonIgnoreProperties(ignoreUnknown = true)
public class FeatureCollection {

    private String type;

    public String getType() {
        return type;
    }
}

当我通过spring-boot run运行该命令时，我在命令行中得到以下结果：

tons of info,


[INFO] Attaching agents: []
14:54:02.566 [main] DEBUG o.s.web.client.RestTemplate - Created GET request for "http://www.trafficlink-online.nl/trafficlinkdata/wegdata/TrajectSensorsNH.GeoJSON"
14:54:02.634 [main] DEBUG o.s.web.client.RestTemplate - Setting request Accept header to [application/json, application/*+json]
14:54:02.719 [main] DEBUG o.s.web.client.RestTemplate - GET request for "http://www.trafficlink-online.nl/trafficlinkdata/wegdata/TrajectSensorsNH.GeoJSON" resulted in 200 (OK)
Exception in thread "main" org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class FeatureCollection] and content type [text/plain;charset=UTF-8]
        at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:108)
        at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:795)
        at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:779)
        at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:559)
        at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:512)
        at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:268)
        at Application.main(Application.java:13)

有什么我没看到的吗？

Answer 1

Could not extract response: no suitable HttpMessageConverter found for response type [class FeatureCollection] and content type [text/plain;charset=UTF-8]

检查您的依赖项，看看是否有Jackson消息转换器在那里。您需要将所使用的JSON转换为Java对象。如果它在您的依赖项中比我想的要好，如果您在主类之上使用@SpringBootApplication，Spring会自动将您正在使用的JSON转换为Java对象。

在eclipse中，尝试转到New-->Spring starter Project-->并选择web，也许还有rest，然后使用该项目使用rest。