Develop Reference

Retrofit adding extra slashes when I upload data

I'm developing an Android app using Retrofit to connect to a Spring Boot server.
When I update data, there are extra slashes and double quotes on the server.
This is the output of POST method. "open"
This is the output of PUT method. "\"open\""
I read a similar article and I'm guessing I encode twice, but I don't know where I'm doing it. Please help me.
This is the service class of Android.
#PUT("/posts/close/update/{id}")
fun updateClose(#Path("id") id: Long, #Body close: String): Call<ResponseBody>
This is the view.
onClick = {
val moshi = Moshi.Builder()
.add(KotlinJsonAdapterFactory())
.build()
val retrofit = Retrofit.Builder()
.baseUrl("https://*****.com")
.addConverterFactory(MoshiConverterFactory.create(moshi))
.build()
thread {
try {
val service: PostService =
retrofit.create(PostService::class.java)
service.updateClose(6, "open")
.enqueue(object : Callback<ResponseBody> {
override fun onResponse(
call: Call<ResponseBody>,
response: Response<ResponseBody>
) {
Log.d("Response is", "${response.body()}")
}
override fun onFailure(
call: Call<ResponseBody>,
t: Throwable
) {
Log.d("Hi", "error")
}
})
} catch (e: Exception) {
Log.d("response-weather", "debug $e")
}
}
This is the repository of Spring Boot.
#Modifying
#Transactional
#Query("UPDATE posts SET close = :close where post_id = :id", nativeQuery = true)
fun updateClose(#Param("id") id: Long, #Param("close") close: String)
Thank you very much.

There is nothing wrong with the data or the android side.
Strings in JSON must be written in double quotes. For more info refer this page.
Your JSON data is {"name": "Ken", "uid": "12345"}
In order to use double quotes inside a string you have to escape it via a backslash. For more info refer this question.
That's the reason for the extra backslashes.
I tried to load the json string via python and it worked like a charm. Attaching screenshot for reference. So any backend you would be using will be able to parse the JSON String.

Finally, I got the codes which work fine.
Service Class of Android.
#PUT("/posts/close/update/{id}")
fun updateClose(#Path("id") id: Long, #Query("close") close: String): Call<ResponseBody>
Controller class of Spring Boot. Before, I used #RequestBody instead of #RequestParam.
#PutMapping("/posts/close/update/{id}")
fun updateClose(#PathVariable id: Long, #RequestParam close: String) = postService.updateClose(id, close)

Twitter oauth/request_token 200 code with empty response body

I'm implementing Twitter OAuth flows as per:
https://developer.twitter.com/en/docs/authentication/guides/log-in-with-twitter
I am getting a response back for the first step (oauth/request_token) which has a 200 code, but the response body is completely empty.
I'm using Retrofit to call the API, and have hooked up an interceptor OkHttpClient to debug the response like so:
val client = OkHttpClient.Builder().also { builder ->
builder.addInterceptor { chain ->
val request = chain.request()
val response = chain.proceed(request)
response
}
}.build()
Then setting up Retrofit like so:
Retrofit.Builder()
.baseUrl(TWITTER_AUTH_BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.client(client)
.build()
.create(TwitterAuthRetrofit::class.java)
.getRequestToken(
authorizationHeaders
).enqueue(object : Callback<TwitterRequestToken> {
override fun onResponse(call: Call<TwitterRequestToken>, response: Response<TwitterRequestToken>) {
onSuccess(response.body())
}
override fun onFailure(call: Call<TwitterRequestToken>, t: Throwable) {
onFailure()
}
})
When I debug in the interceptor, I can see the response is successful (200) but the response body is empty, which I think is causing my Gson deserialization to fail.
The result of calling response.body.contentLength() in the interceptor is -1.
The result of calling response.code in the interceptor is 200.
Here is the model I am attempting to deserialize the response body to:
data class TwitterRequestToken(
#SerializedName(value = "oauth_token")
val token: String,
#SerializedName(value = "oauth_token_secret")
val tokenSecret: String,
#SerializedName(value = "oauth_callback_confirmed")
val callbackConfirmed: Boolean
)
Note I am using #SerializedName to provide the keys for the response body, whilst the names of my properties are arbitrary to our app (we use camel case). I add a GsonConverterFactory to the Retrofit instance using the builder and have done this in the same way for many other requests before with no issues.
Here is the response I am getting from the API, which I am looking at via debugging in the interceptor above:
Response{protocol=h2, code=200, message=, url=https://api.twitter.com/oauth/request_token}
And here is the cause message from the Throwable I am getting in the onFailure callback from Retrofit:
com.google.gson.stream.MalformedJsonException:
Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $
Has anyone got any idea what might cause this?

Finally figured it out, hope this helps someone in future...
The response body from the Twitter API for oauth/request_token isn't encoded as JSON; you will need to read it from the response buffer. Specifically, when implementing the API with Retrofit, you will want your Retrofit interface to return ResponseBody (rather than your custom class), remove GSON from the Retrofit builder and, in the onResponseCallback from Retrofit, write the following code to read the buffer to a string, then split the string on & to get each key val pair, then you can split each of these on = and make sure you have all 3 values before constructing your model:
override fun onResponse(call: Call<ResponseBody>, response: Response<ResponseBody>) {
response.body()?.also { body ->
body.source().readString(Charsets.UTF_8).split('&').map { param ->
param.split('=').let { keyVal ->
keyVal[0] to keyVal[1]
}
}.toMap().let { paramMap ->
val oauthToken = paramMap["oauth_token"]
val oauthTokenSecret = paramMap["oauth_token_secret"]
val oauthCallbackConfirmed = paramMap["oauth_callback_confirmed"]?.toBoolean()
if (oauthToken == null || oauthTokenSecret == null || oauthCallbackConfirmed == null) {
onFailure()
} else {
onSuccess(
TwitterRequestToken(
oauthToken,
oauthTokenSecret,
oauthCallbackConfirmed
)
)
}
}
} ?: onFailure()
}

Always getting 401 when using android device but not in Postman

I am sending my token as Authorization in Retrofit but I always get a 401 code. But if I use the same token in Postman, I can get access. I know I am able to access the webapi because I can Login just fine and able to get the token from the Web Api. Please see my code below:
ApiService Interface
#POST("consolidated/sample")
fun sample(#Header("Authorization") token: String): Call<ResponseBody>
Calling the Service
private fun pushTransactionsToWebApi() {
val vApiService = ApiServiceBuillder.buildService(ApiService::class.java)
CoroutineScope(Main).launch {
var token = SharedDataManager.getInstance(context!!).applicationToken
var tokenArr = token!!.split(':')
responseFromApi = tokenArr[1] ==> I use this so I can remove the word "token" at the beginning of the token string
token = "Bearer ${responseFromApi}"
Log.i("TAG", "${token}") ==> ####
val call = vApiService.sample(token)
if(!call.isExecuted) {
call.enqueue(object : Callback<ResponseBody>{
override fun onFailure(call: Call<ResponseBody>, t: Throwable) {
responseFromApi = t.message
}
override fun onResponse(
call: Call<ResponseBody>,
response: Response<ResponseBody>
) {
if(response.isSuccessful){
Toast.makeText(context, "We are OK", Toast.LENGTH_LONG).show()
} else {
progressDialog!!.dismiss()
Toast.makeText(context, "We are NOT OK", Toast.LENGTH_LONG).show()
}
}
})
}
}
}
### => Result in my Log.i()
2020-04-08 13:03:09.235 14185-14185/com.kotlin.ambulantlcs I/TAG:
Bearer
"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.m1mZw79KLIxq4pZPmBRbN7TjILvhvbUIJOCWDEM8I-k"}
If I paste this in my Postman, I can get access
What do I need to do? Thank you!

From our conversation in the comments, it seems like you're getting a json {"token": "..."} from SharedDataManager.getInstance(context!!).applicationToken. This explains why when you split in : you get printed in the log "..."}.
There are a lot of ways to deserialize json in Android. Here are some options. I think the vanilla way is something like:
val root = JSONObject(SharedDataManager.getInstance(context!!).applicationToken)
val token = root.getString("token")
With this you'll have the token in token.
However, if you already have a json library you could use it. For example, with gson you could do something like:
data class TokenData(
#SerializedName("token")
val token: String)
val token = Gson().fromJson(
SharedDataManager.getInstance(context!!).applicationToken,
TokenData::class.java)
You can now use token.
With Moshi using the kotlin gen library - com.squareup.moshi:moshi-kotlin-codegen - you can define the above model like:
#JsonClass(generateAdapter = true)
data class TokenData(
#Json(name = "token")
val token: String)
// Then get it like:
val token = Moshi.Builder()
.build()
.adapter(TokenData::class.java)
.fromJson(SharedDataManager.getInstance(context!!).applicationToken)
These are just some options. There's also the popular Jackson. Pick the one that suits best your needs. Hope this helps

Remove " " quotes from token
make sure that keys must be same
pass token like as:
Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.m1mZw79KLIxq4pZPmBRbN7TjILvhvbUIJOCWDEM8I-k

how to handle error in okhttp3 without crash

I am using the following method to handle my requests
override fun intercept(chain: Interceptor.Chain): Response = chain.proceed(chain.request())
.let { originalResponse ->
Log.i("AMIRA999", "code : " + originalResponse.code())
when (originalResponse.code()) {
200 -> {
Log.i("AMIRA999", "body : " + getErrorResponse(originalResponse))
originalResponse
}
401, 404 -> {
Log.i("AMIRA999", "body : " + getErrorResponse(originalResponse))
originalResponse
/*return originalResponse.mapToBody(
originalResponse.body()?.contentType(),
getErrorResponse(originalResponse)
)*/
}
else -> {
Log.i("AMIRA999", "body : " + originalResponse.body().toString())
throw BadRequestException()
}
}
}
the method work perfect when the code is 200, but it crash if the code is 404 or 401
what I need to keep returning the json comes from server and does not crash to be able to handle it with error message
how can I do that ?
the crash that I got is the following
retrofit2.HttpException: HTTP 401 UNAUTHORIZED
at com.jakewharton.retrofit2.adapter.kotlin.coroutines.CoroutineCallAdapterFactory$BodyCallAdapter$adapt$2.onResponse(CoroutineCallAdapterFactory.kt:104)
at retrofit2.OkHttpCall$1.onResponse(OkHttpCall.java:129)
at okhttp3.RealCall$AsyncCall.execute(RealCall.java:206)
at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)

You use retrofit2-kotlin-coroutines-adapter and the exception throwing is by design. Any non-2xx HTTP response such as 401 will throw an exception. You can see this for yourself in the library source code
if (response.isSuccessful) {
deferred.complete(response.body()!!)
} else {
deferred.completeExceptionally(HttpException(response))
}
But this is not a problem. You can still access the response and your JSON by doing catch (e: HttpException) and then calling val yourJson = e.response()?.body() as? YourJson.
Note that retrofit2-kotlin-coroutines-adapter is deprecated and that you should migrate to Retrofit 2.6.0 or newer. Then you can prefix your Retrofit interface functions with suspend so you can write nice idiomatic Kotlin code.

Retrofit 2 has a different concept of handling "successful" requests than Retrofit 1. In Retrofit 2, all requests that can be executed (sent to the API) and for which you’re receiving a response are seen as "successful". That means, for these requests the onResponse callback is fired and you need to manually check whether the request is actually successful (status 200-299) or erroneous (status 400-599).
If the request finished successfully, we can use the response object and do whatever we wanted. In case the error actually failed (remember, status 400-599), we want to show the user appropriate information about the issue.
Example
Error Object
Let’s assume your API sends a JSON error body like this:
{
statusCode: 409,
message: "Email address already registered"
}
Note: you can see your JSON error body by printing response.errorBody()
To avoid these bad user experiences, we’re mapping the response body to a Java object, represented by the following class.
class APIError {
private val statusCode:Int = 0
private val message:String
fun status():Int {
return statusCode
}
fun message():String {
return message
}
}
Error Handler
object ErrorUtils {
fun parseError(response:Response<*>):APIError {
val converter = ServiceGenerator.retrofit()
.responseBodyConverter(APIError::class.java, arrayOfNulls<Annotation>(0))
val error:APIError
try
{
error = converter.convert(response.errorBody())
}
catch (e:IOException) {
return APIError()
}
return error
}
}
Error Handler in Action
Now you can handle error in API response using ErrorUtils like the following.
val call = service.me()
call.enqueue(object:Callback<User>() {
fun onResponse(call:Call<User>, response:Response<User>) {
if (response.isSuccessful())
{
// use response data and do some fancy stuff :)
}
else
{
// parse the response body …
val error = ErrorUtils.parseError(response)
// … and use it to show error information
// … or just log the issue like we’re doing :)
Log.d("error message", error.message())
}
}
fun onFailure(call:Call<User>, t:Throwable) {
// there is more than just a failing request (like: no internet connection)
}
})
The complete example with a video is here retrofit-2-error-handling.

How can I capture a Retrofit response error in onResponse?

I'm using Retrofit2 in an Android app. Here's my response code:
override fun onResponse(call: Call<Asset>?, response: Response<Asset>?) {
val errorStart = response?.errorBody()?.string() // I get "ERROR" here
if (response != null && response.isSuccessful) {
// A successful response was returned
completion(response.body(), null)
} else {
// Not success
val errorElse = response?.errorBody()?.string() // I get "" here
val error = Error(errorText)
completion(null,error)
}
}
and here's the code I'm using to test my code:
response = Response.Builder()
.code(403)
.message(responseString)
.request(chain.request())
.protocol(Protocol.HTTP_1_0)
.body(ResponseBody.create(MediaType.parse("application/json"), "ERROR"))
.addHeader("content-type", "application/json")
.build()
When the code run and a response is returned response?.errorBody()?.string() is a string and I can capture it, as I have in this code as val errorStart.
...But...
when I run the IF code/logic and attempt to capture response?.errorBody()?.string() in the else code block it's now blank/gone.
Can someone explain what's going on or what I'm doing wrong? What is the proper way to capture error information in OnResponse?

First of all the errorBody() is of type stream, meaning that it is not read until you call the method. Streams can be read only once, take a look here for a detailed explanation.