https://stackoverflow.com/questions/49746944

Controller.java

package io.github.areguig.demo;

import net.sf.json.JSONException;
import net.sf.json.JSONObject;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.client.RestTemplate;

@RestController
public class Controller {

    @RequestMapping(value = "/api/in", method = RequestMethod.PUT, consumes = "application/json")
    public ResponseEntity<?> updateProject(
            @RequestBody ProjectMetadata metadata) throws JSONException {

        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        headers.add("Authorization", "Basic <aut key>");

        JSONObject requestBody = new JSONObject();
        requestBody.put("label", metadata.getLabel());
        requestBody.put("description", metadata.getDescription());
        requestBody.put("shortDesc", metadata.getShortDesc());
        requestBody.put("tags", metadata.getTags());
        System.out.println("requestBody" + requestBody);

        HttpEntity<JSONObject> requestEntity = new HttpEntity<>(requestBody, headers);
        System.out.println("requestentity" + requestEntity.toString());

        RestTemplate restTemplate = new RestTemplate();
        String url = "http://localhost:8080/api/external";
        System.out.println("trying to send request to create project");
        ResponseEntity<?> createResponse = null;

        try {
            createResponse = restTemplate.exchange(url, HttpMethod.PUT, requestEntity, String.class);
            // restTemplate.put(url, requestEntity,projectKey);
        } catch (HttpClientErrorException e) {

            System.out.println("Exceptions occurred while processing the request::");
            return new ResponseEntity<String>(e.getResponseBodyAsString(), HttpStatus.BAD_REQUEST);
        }
        return createResponse;
    }


    @RestController
    public class ControllerExternal {

        @PutMapping(value = "/api/external")

        public String putExternal(@RequestBody ProjectMetadata projectProjectMetadata){
            if(projectProjectMetadata.getTags()==null){
                System.out.printf("no tags");
            }
            System.out.printf("EXTERNAL "+ JSONObject.fromObject(projectProjectMetadata).toString());
            return JSONObject.fromObject(projectProjectMetadata).toString();
        }
    }
}

Hey arguig,thanks for working on my code but just fyi the request is forming correctly but the operation is failing @put

requestBody{"description":"adsfy","shortDesc":"nsfdf","label":"testapp","tag":["tag12"]}
2018-04-10 13:54:10,362 8682 [http-nio-9080-exec-10] DEBUG c.p.controller.ProjectController - requestentity<{"description":"adsfy","shortDesc":"nsfdf","label":"testapp","tag":["tag12"]},{Content-Type=[application/json], Authorization=[Basic aut]}>
2018-04-10 13:54:10,370 8690 [http-nio-9080-exec-10] DEBUG c.p.controller.ProjectController - trying to send request to dataiku to create project
2018-04-10 13:54:10,394 8714 [http-nio-9080-exec-10] DEBUG o.s.web.client.RestTemplate - Created PUT request for "http://<>/public/api/projects/abcde/metadata/"
2018-04-10 13:54:10,398 8718 [http-nio-9080-exec-10] DEBUG o.s.web.client.RestTemplate - Setting request Accept header to [text/plain, application/json, application/*+json, /]
2018-04-10 13:54:10,398 8718 [http-nio-9080-exec-10] DEBUG o.s.web.client.RestTemplate - Writing [{"description":"adsfy","shortDesc":"nsfdf","label":"testapp","tag":["tag12"]}] as "application/json" using [org.springframework.http.converter.StringHttpMessageConverter@189c0555]
2018-04-10 13:54:10,954 9274 [http-nio-9080-exec-10] DEBUG o.s.web.client.RestTemplate - PUT request for "http://<>/public/api/projects/abcde/metadata/" resulted in 500 (Server Error); invoking error handler