Invalid mimetype exception in Spring boot rest call - spring-boot

I am new to both Spring boot and rest calls.
I am trying to consume a rest service and I do not have any information about that rest API except URL. When I hit that URL from a browser I am getting a response as {key:value}. So, I assumed that it is a JSON response.
I am consuming it in spring boot as follows
restTemplate.getForObject(url, String.class) .
This is giving Invalid mime type "content-type: text/plain; charset=ISO-8859-1": Invalid token character ':' in token "content-type: text"
I assume that this error is because response content type is set to text/plain but it is returning JSON format.
EDIT:
Tried this way but did not work.
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<String> entity = new HttpEntity<String>("parameters",headers);
ResponseEntity<String> result = restTemplate.exchange(url,HttpMethod.GET,
entity, String.class);
How to handle and solve it?

You might want to read about the request headers your REST API needs. Content-Type header specifies the media type of the request you're sending to the server. Because you're just getting data from the server you should set the Accept header to the kind of response you want i.e., Accept: application/json.
Unfortunately, you can't set headers using getForObject(). You could try this:
URL url = new URL("Enter the URL of the REST endpoint");
con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("GET");
con.setRequestProperty("Accept", "application/json");
if (con.getResponseCode() == HttpURLConnection.HTTP_OK) {
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
StringBuffer content = new StringBuffer();
String inputLine;
while ((inputLine = in.readLine()) != null) {
content.append(inputLine);
}
in.close();
}

Related

OkHttp - keep getting the error: "content-type of request should be application/json"

Why do I get this error "content-type of request should be application/json", because I encoded it application/json?
How to correct it?
In Postman the request is working fine.
int id = 208;
MediaType JsonType = MediaType.parse("application/json");
OkHttpClient client = new OkHttpClient();
String jsonBody = "{\"params\":[\"wandelnet\"," + id + "]}";
RequestBody body = RequestBody.create(jsonBody, JsonType);
Request request = new Request.Builder()
.url( "https://wandelnet.api.routemaker.nl/routemaker/getPublishedRoute")
.post(body)
.addHeader("Content-Type", "application/json; charset=utf-8")
.addHeader( "Accept", "application/json")
.build();
Response response = client.newCall(request).execute();
The result is:
{"result":null,"error":{"code":"sherpaBadRequest","message":"content-type
of request should be application/json"}}
Try creating the request body from bytes, not from a string:
RequestBody body = RequestBody.create(jsonBody.getBytes(“UTF-8”), JsonType);
OkHttp automatically adds a charset when it does string encoding, and we need to prevent this here.
You’ll also want to omit the Content-Type header in your request builder.

sending GET request via REST template with JSON request body getting failed with binding binding element must be a struct error?

I am trying to send a GET request using REST Template with a JSON request body, but the request is failing with error,
processing
failedorg.springframework.web.client.HttpServerErrorException$InternalServerError:
500 Internal Server Error: [code=400, message=binding element must be
a struct]
I have tried hitting the endpoint using the insomnia and the request is going through successfully, There I have put 2 headers
1. Content-Type - application/json
2. Authorization - Bearer ******
And the JSON body.
My code in spring boot looks like this.
ResponseEntity<String> responseObject = null;
String URL = "https://myurl/endpoint";
String requestBody = "{\"requestType\":\"status\"}";
HttpHeaders headers = new HttpHeaders();
headers.add("Authorization","Bearer ***");
headers.setContentType(MediaType.APPLICATION_JSON);
HttpEntity httpEntity = new HttpEntity<>(body,headers);
System.out.println(httpEntity+" httpEntity");
System.out.println(headers+" headers");
responseObject = restTemplate.exchange(URL, HttpMethod.GET, httpEntity, String.class);
The sout for httpentity and header looks like this
httpEntity
<{"requestType":"status"},[Authorization:"Bearer *******************", Content-Type:"application/json"]>
headers
[Authorization:"Bearer *************************", Content-Type:"application/json"]
Also when I am trying to send a request without the body to another endpoint using rest template, that is getting executed successfully, so I think something with the way I am sending the body has to do with the error.
rest template doesn't support get request with body . for more details you can refer this article.
If you are on Java 11 I would suggest you to use java.net.HttpClient which will fulfill your need.

how to handle "Transfer-Encoding=chunked" in SI HttpRequestExecutingMessageHandler

I am calling an external server using HttpRequestExecutingMessageHandler. I am using a JSON to object transformer to convert the JSON data. But I am getting the following exception.
Caused by: com.fasterxml.jackson.core.JsonParseException: Illegal character ((CTRL-CHAR, code 31)): only regular white space (\r, \n, \t) is allowed between tokens
at [Source: (String)"�
when I checked the headers I found the following.
Transfer-Encoding=chunked
Is this the reason for the exception log?
The outbound gateway and JsonToObjectTransformer are given below:
#ServiceActivator(inputChannel = "channelOutboundRequest")
#Bean
public HttpRequestExecutingMessageHandler outboundGateway() {
final HttpRequestExecutingMessageHandler handler = new HttpRequestExecutingMessageHandler(
endpoint);
handler.setExpectedResponseType(String.class);
handler.setHttpMethod(HttpMethod.POST);
handler.setOutputChannelName("channelResponse");
handler.setAdviceChain(Collections.singletonList(advice()));
return handler;
}
#Bean
#Transformer(inputChannel = "channelResponse", outputChannel = "channelReply")
public JsonToObjectTransformer transformer(ObjectMapper objectMapper) {
final JsonObjectMapper<?, ?> mapper = new Jackson2JsonObjectMapper(objectMapper);
return new JsonToObjectTransformer(DetailsDTO.class, mapper);
}
If the header is causing the issue, how can I handle the response?
Note: If I hit the external server directly using postman, I am getting the response in JSON structure.
I have no idea what's wrong here.. If I use the simple restemplate call like below, it works properly.
JSONObject jsonObject = new JSONObject("{\"code\":\"F001\",\"transactionId\":\"1008566223232\"}");
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
headers.setBearerAuth("token");
HttpEntity<String> request =
new HttpEntity<String>(jsonObject.toString(), headers);
String respns = restTemplt.postForObject("http://endpoint", request, String.class);
System.out.println(respns);
JSONObject response = new JSONObject(respns);
One difference I could find was in the response headers. those are given below:
Outbound gateway response headers :-
{Transfer-Encoding=chunked, http_requestMethod=GET, errorChannel=org.springframework.messaging.core.GenericMessagingTemplate$TemporaryReplyChannel#d8b195e, Server=nginx, Accept=/, Connection=keep-alive, User-Agent=PostmanRuntime/7.28.0, Host=localhost:8901, Accept-Encoding=gzip, deflate, br, http_statusCode=200 OK, Date=1622533072000, Authorization=Bearer token, replyChannel=org.springframework.messaging.core.GenericMessagingTemplate$TemporaryReplyChannel#d8b195e, Cache-Control=no-cache, ETag=W/"1009-5SzdL+uWyY6ZcMWht5dMtm2Sxlc", Content-Encoding=gzip, http_requestUrl=http://inboundurl, id=be07fc8d-d478-5fa9-33e4-61a2b5f92468, Content-Length=207, contentType=application/json;charset=utf-8, Content-Type=application/json, requestFrom=CUSTOM_HEADER, timestamp=1622533092827}
Normal restTemplate call response header
[Server:"nginx", Date:"Tue, 01 Jun 2021 07:34:54 GMT", Content-Type:"application/json; charset=utf-8", Content-Length:"4105", Connection:"keep-alive", Access-Control-Allow-Origin:"*", Content-Security-Policy:"default-src 'self';base-uri 'self';block-all-mixed-content;font-src 'self' https: data:;frame-ancestors 'self';img-src 'self' data:;object-src 'none';script-src 'self';script-src-attr 'none';style-src 'self' https: 'unsafe-inline';upgrade-insecure-requests", X-DNS-Prefetch-Control:"off", Expect-CT:"max-age=0", X-Frame-Options:"SAMEORIGIN", Strict-Transport-Security:"max-age=15552000; includeSubDomains", X-Download-Options:"noopen", X-Content-Type-Options:"nosniff", X-Permitted-Cross-Domain-Policies:"none", Referrer-Policy:"no-referrer", X-XSS-Protection:"0", ETag:"W/"1009-llD9DqxYkEsjyikWajYk+16cb1k""]
Can anyone please help?
After many trials and errors, I found the reason for this. Accept-Encoding=gzip, deflate, br this header in the outbound gateway request is the root cause. the response I am getting is a long string and it is getting compressed because of this header. i added a header filter before the outbound gateway to remove this header.
#Bean
#Transformer(inputChannel = "channelHeaderFilterReq", outputChannel = "channelHeaderFilterRes")
public HeaderFilter filter() {
return new HeaderFilter("Accept-Encoding");
}
Now everything works fine..!!

How to remove and add new Accept header to Spring boot Rest Template?

I'm consuming a GraphQL Service, it is returning 406 Not Acceptable if the Accept header is text/plain.
It is expecting to Accept as application/json
So I tried override the RestTeamplate Headers. However it seems the Accept header test/plain is always present there. I confirmed this by enabling debug(logging.level.org.springframework.web.client.RestTemplate=DEBUG)
Console
o.s.web.client.RestTemplate: Accept=[text/plain, application/json, application/*+json, */*]
o.s.web.client.RestTemplate: Writing [{products(query: "title:tow*", first: 10) {edges {node {id legacyResourceId title}}}}] as "application/graphql"
Here is the code I tried to override the Accept header
HttpHeaders headers = new HttpHeaders();
RestTemplate restTemplate = new RestTemplate();
headers.add("Content-Type","application/graphql");
headers.setAccept(Collections.singletonList(new MediaType("application","json")));
String content = "{products(query: \"title:tow*\", first: 10) {edges {node {id title}}}}";
HttpEntity<String> requestEntity = new HttpEntity<String>(content, headers);
ResponseEntity<String> response = restTemplate.exchange(url, HttpMethod.POST, requestEntity, String.class);
I even tried removing the Accept header first(headers.remove("Accept")) and then setAccept but still it doesn't remove it from the log.
Is there anything else need to be done?
Why is it not removing the text/plain from the Accept header?
Why I see multiple options in Accept when I set only one option?

Having trouble recreating a cURL command in a Spring RestTemplate Using Headers

Here's the curl command I'm trying to recreate :
curl https://bannana-pajamas.com/services/data/v20.0/query/?q=BananaQuery -H 'Authorization: Bearer Banana_Token'
This curl command works just fine in my terminal and returns a json file.
Here's my attempt at recreating it in a Spring Rest Template:
//Create a rest template
RestTemplate rest = new RestTemplate();
System.out.println("This here is the token "+Banana_Token);
//Create the headers
HttpHeaders headers = new HttpHeaders();
headers.set("Authorization","Bearer "+Banana_Token);
HttpEntity<String> entity = new HttpEntity<>(headers);
//Create the url
String url = "https://bannana-pajamas.com/services/data/v20.0/query/?q=BananaQuery";
String response;
try{
response = rest.exchange(url, HttpMethod.GET, entity, String.class).toString();
}catch(Exception error){
System.out.println("This still ain't working bro. Imma make this null till you get stuff right");
response = null;
}
return response;
When I run this, I get the following error:
org.springframework.web.client.HttpClientErrorException: 400 Bad Request
I've tried several of the similar answers on this site, but I keep getting that error. I probably missing something very minor.
Anybody have any ideas?
Thanks!

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