Java 使用 spring 中的 rest 模板通过 post 调用发送 json 数据

send json data through a post call by using rest template from spring

提问by РАВИ

I keep getting an error saying that this is not valid json data and keep getting error 400. I don't think the implementation I have is formatting data properly. Goal: trying to make a post call using a rest template, by passing in JSON data as the body. It seems that when converting from map to json data, it isn't properly converted to json.

我不断收到错误消息，说这不是有效的 json 数据，并不断收到错误 400。我认为我的实现没有正确格式化数据。目标：通过将 JSON 数据作为正文传入，尝试使用 rest 模板进行后期调用。似乎在从 map 转换为 json 数据时，它没有正确转换为 json。

public void GetJsonData(String name, String city) {
        Map<String, String> map = new HashMap<String, String>();
        map.put("api_key", apikey);



map.put("venue_queries", "[{'name':'"+name+"', 'location': {'locality': '"+city+"'}}]");

        try {
            String resp = GlobalHelper.calltestService(RestServicesUrl, map);
            System.out.println(resp);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }


public String calltestService(String url, Map<String, String> data) throws Exception {
        RestTemplate rest = new RestTemplate();
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
        ResponseEntity<String> response = new ResponseEntity<String>(headers, HttpStatus.OK);
        rest.getMessageConverters().add(new MappingHymanson2HttpMessageConverter());
            Gson gson = new Gson();
            System.out.println(gson.toJson(data));
        try {
            response = rest.postForEntity(url, gson.toJson(data), String.class);
            System.out.println(response.getBody()); 
            System.out.println(response.getHeaders());
            return response.getBody();
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("error in post entity");
            return "error";
        }
    }

采纳答案by vzamanillo

Right, your resulting JSON is not valid

是的，您生成的 JSON 无效

{
    "venue_queries": "[{\u0027name\u0027:\u0027yo\u0027, \u0027location\u0027: {\u0027locality\u0027: \u0027Solares\u0027}}]",
    "api_key": "asfasdfasfdasdfasdfa"
}

you JSON is not valid because GSON escapes the HTML characters by default and put the single quotes as the equivalent unicode char code U+0027

您的 JSON 无效，因为 GSON 默认情况下会转义 HTML 字符并将单引号作为等效的 Unicode 字符代码 U+0027

if you disable the Gson HTMLEscaping

如果您禁用Gson HTMLEscaping

GsonBuilder builder = new GsonBuilder();
builder.disableHtmlEscaping();
Gson gson = builder.create();

you will get

你会得到

{
    "venue_queries": "[{'name':'yo', 'location': {'locality': 'Solares'}}]",
    "api_key": "asfasdfasfdasdfasdfa"
}

anyway, your JSON is still incorrect.

无论如何，您的 JSON 仍然不正确。

You have to fix your venue_querieskey content int the map using double quotes"

您必须venue_queries在地图中修复您的关键内容using double quotes"

map.put("venue_queries", "[{\"name\":\""+name+"\", \"location\": {\"locality\": \""+city+"\"}}]");

then your resulting JSON will be valid

那么您生成的 JSON 将是有效的

{
    "venue_queries": "[{\"name\":\"yo\", \"location\": {\"locality\": \"Solares\"}}]",
    "api_key": "asfasdfasfdasdfasdfa"
}

Tes snippet

测试片段

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

import com.google.gson.Gson;

public class GsonMap {

    public static void main(String[] args) {
        Map<String, String> map = new HashMap<String, String>();
        String apikey = "asfasdfasfdasdfasdfa";
        map.put("api_key", apikey);
        String name = "yo";
        String city = "Solares";
        map.put("venue_queries", "[{\"name\":\""+name+"\", \"location\": {\"locality\": \""+city+"\"}}]");
        Gson gson = new Gson();
        String json = gson.toJson(map);
        System.out.println("Resulting JSON:" + json);
        map = gson.fromJson(json, map.getClass());
        System.out.println("Resulting map values:");
        for (Entry<String, String> entry : map.entrySet()) {
            System.out.println("Key:" + entry.getKey() + ", value:" + entry.getValue());
        }
    }
}