I have API method mapping like this
#POST("api/updateStarted/{id}/{started}")
suspend fun updateStarted(
#Path("id") id: Int,
#Path("started") started: Date
) : Response <Int>
I want to use yyyy-MM-dd'T'HH:mm:ss format everywhere. My API adapter looks like this:
val gson = GsonBuilder().setDateFormat("yyyy-MM-dd'T'HH:mm:ss")
val apiClient: ApiClient = Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create(gson.create()))
.baseUrl(API_BASE_URL)
.client(getHttpClient(API_USERNAME, API_PASSWORD))
.addConverterFactory(GsonConverterFactory.create())
.build()
.create(ApiClient::class.java)
However GsonBuilder().setDateFormat("yyyy-MM-dd'T'HH:mm:ss") cannot affect date format when I pass it thru URL (because that's not JSON) so Retrofit builds URL like this:
http://myserver.com/api/updateFinished/2/Fri%20Jan%2027%2013:48:42%20GMT+01:00%202023
instead of something like this:
http://myserver.com/api/updateFinished/2/2023-01-28T02:03:04.000
How can I fix that? I'm new in Retrofit and I don't fully understand date/time libraries in Java.
You can switch the data type from java.util.Date to java.time.LocalDateTime if you want your desired format using the toString() method of that data type.
Currently, you have Date.toString() producing an undesired result.
If you don't have to use a Date, import java.time.LocalDateTime and just change your fun a little to this:
#POST("api/updateStarted/{id}/{started}")
suspend fun updateStarted(
#Path("id") id: Int,
#Path("started") started: LocalDateTime
) : Response <Int>
GsonConverterFactory supports responseBodyConverter and requestBodyConverter which aren't used to convert URL params. For that, you need a stringConverter which, fortunately is trivial to implement:
class MyToStringConverter : Converter<SomeClass, String> {
override fun convert(value: SomeClass): String {
return formatToMyDesiredUrlParamFormat(value)
}
companion object {
val INSTANCE = MyToStringConverter()
}
}
class MyConverterFactory : Converter.Factory() {
override fun stringConverter(type: Type, annotations: Array<out Annotation>, retrofit: Retrofit): Converter<*, String>? {
return if (type == SomeClass::class.java) {
//extra check to make sure the circumstances are correct:
if (annotations.any { it is retrofit2.http.Query }) {
MyToStringConverter.INSTANCE
} else {
null
}
} else {
null
}
}
}
and then
val apiClient: ApiClient = Retrofit.Builder()
.baseUrl(API_BASE_URL)
.client(getHttpClient(API_USERNAME, API_PASSWORD))
.addConverterFactory(GsonConverterFactory.create())
.addConverterFactory(MyConverterFactory())
//(...)
I've added checking for annotations as example if one would want tighter control on when the converter is used.
Related
I used the data type java.util.UUID in my data models and I have used Moshi for serialization.
But I encountered an error saying that "Platform class java.util.UUID requires explicit JsonAdapter to be registered"
I have gone through the documentation of Moshi for writing custom adapters and I tried to replicate it accordingly.
I wrote an adapter and added it to a moshi instance. But still I encounter the same error .
Adapter
class UUIDAdapter {
#ToJson
fun toJson(value:java.util.UUID):java.util.UUID{
return value
}
#FromJson
fun fromJson(value: String):java.util.UUID{
return java.util.UUID.fromString(value)
}
}
Model
#JsonClass(generateAdapter = true)
data class AddWorkspace(
#Json(name = "user_id")
val user_id: UUID,
#Json(name = "name")
val name:String,
#Json(name = "descp")
val descp:String,
#Json(name = "created_at")
val created_at:String
)
Moshi
private val moshi = Moshi.Builder()
.add(UUIDAdapter())
.build()
private val retrofitBuilder = Retrofit.Builder()
.baseUrl(baseUrl)
.addConverterFactory(MoshiConverterFactory.create(moshi))
What else am I missing so that I can use the adapter correctly ?
Edit : Well, the methods toJson and fromJson are not being called in the first place. I tried to implement the JsonAdapter class and override the methods toJson and fromJson, but the issue I face here is that in case of the method toJson, I need to send a java.util.UUID value, but the JsonWriter cannot write a value of such data type.
Please suggest me a way to work my way through this. Thanks :)
UUID adapter
class UUIDAdapter:JsonAdapter<UUID>(){
#FromJson
override fun fromJson(reader: JsonReader): UUID? {
return UUID.fromString(reader.readJsonValue().toString())
}
#ToJson
override fun toJson(writer: JsonWriter, value: UUID?) {
writer.jsonValue(value)
}
}
You're so close. Change the #ToJson to this:
#ToJson
fun toJson(value:java.util.UUID): String {
return value.toString()
}
as Jesse described just use:
class UuidAdapter {
#FromJson
fun fromJson(uuid: String): UUID = UUID.fromString(uuid)
#ToJson
fun toJson(value: UUID): String = value.toString()
}
A JSON-API-response contains the following properties:
created_at_timestamp: 1565979486,
timezone: "+01:00",
I am using Moshi and ThreeTenBp to parse the time stamps and prepared the following custom adapters:
class ZonedDateTimeAdapter {
#FromJson
fun fromJson(jsonValue: Long?) = jsonValue?.let {
try {
ZonedDateTime.ofInstant(Instant.ofEpochSecond(jsonValue), ZoneOffset.UTC) // <---
} catch (e: DateTimeParseException) {
println(e.message)
null
}
}
}
As you can see the zone offset is hardcoded here.
class ZonedDateTimeJsonAdapter : JsonAdapter<ZonedDateTime>() {
private val delegate = ZonedDateTimeAdapter()
override fun fromJson(reader: JsonReader): ZonedDateTime? {
val jsonValue = reader.nextLong()
return delegate.fromJson(jsonValue)
}
}
...
class ZoneOffsetAdapter {
#FromJson
fun fromJson(jsonValue: String?) = jsonValue?.let {
try {
ZoneOffset.of(jsonValue)
} catch (e: DateTimeException) {
println(e.message)
null
}
}
}
...
class ZoneOffsetJsonAdapter : JsonAdapter<ZoneOffset>() {
private val delegate = ZoneOffsetAdapter()
override fun fromJson(reader: JsonReader): ZoneOffset? {
val jsonValue = reader.nextString()
return delegate.fromJson(jsonValue)
}
}
The adapters are registered with Moshi as follows:
Moshi.Builder()
.add(ZoneOffset::class.java, ZoneOffsetJsonAdapter())
.add(ZonedDateTime::class.java, ZonedDateTimeJsonAdapter())
.build()
Parsing the individual fields (created_at_timestamp, timezone) works fine. I want however get rid of the hardcoded zone offset. How can I configure Moshi to fall back on the timezone property when parsing the created_at_timestamp property.
Related
Advanced JSON parsing techniques using Moshi and Kotlin
The work-in-progress branch of the related project
For the created_at_timestamp field you should use a type that doesn't have a timezone. This is usually Instant. It identifies a moment in time independent of which timezone it is being interpreted in.
Then in your enclosing type you can define a getter method to combine the instant and zone into one value. The ZonedDateTime.ofInstant method can do this.
I'm a newbie about Kotlin. My first project is to consume a rest api. I already made that using retrofit. But I have a problem when I'm logging the response, my data class is null. I don't know where is the error.
My Rerofit Client
object RetrofitClient {
var retrofit: Retrofit? = null
fun getClient(baseUrl: String): Retrofit? {
if (retrofit == null) {
//TODO While release in Google Play Change the Level to NONE
val interceptor = HttpLoggingInterceptor()
interceptor.level = HttpLoggingInterceptor.Level.BODY
val client = OkHttpClient.Builder()
.addInterceptor(interceptor)
.connectTimeout(100, TimeUnit.SECONDS)
.readTimeout(100, TimeUnit.SECONDS)
.build()
retrofit = Retrofit.Builder()
.client(client)
.baseUrl(baseUrl)
.addConverterFactory(GsonConverterFactory.create())
.build()
}
return retrofit
}
}
My Interface
public interface ApiLoginService {
#POST("UserManagementCoreAPI/api/v1/users")
fun loginService(#Body request: RequestBody): Call<DataLogin>
}
object ApiUtils {
val BASE_URL = "------"
val apiLoginService: ApiLoginService
get() = RetrofitClient.getClient(BASE_URL)!!.create(ApiLoginService::class.java)
}
My class data
data class DataLogin (
#SerializedName("employeeId") val employeeId : String,
#SerializedName("fullName") val fullName : String,
#SerializedName("loginConfins") val loginConfins : String,
#SerializedName("branchId") val branchId : String,
#SerializedName("isActive") val isActive : String
)
Main Activity
mApiLoginService!!.loginService(requestBody).enqueue(object : Callback<DataLogin>{
override fun onResponse(call: Call<DataLogin>, response: Response<DataLogin>) {
if(response.isSuccessful()){
if(response.body().toString() == null){
Log.d(tag,"Null")
}else{
Log.d(tag,"Logging In " + response.body()!!)
progressBar.visibility = View.GONE
btn_submit.visibility = View.VISIBLE
startActivity(Intent(this#MainActivity, HomeActivity::class.java))
}
}else{
Toast.makeText(applicationContext, "Invalid username or password", Toast.LENGTH_LONG).show()
Log.d(tag,"Error " + response.errorBody().toString())
progressBar.visibility = View.GONE
btn_submit.visibility = View.VISIBLE
}
}
override fun onFailure(call: Call<DataLogin>, t: Throwable) {
progressBar.visibility = View.GONE
btn_submit.visibility = View.VISIBLE
}
})
My Respone Log
message: Logging In DataLogin(employeeId=null, fullName=null, loginConfins=null, branchId=null, isActive=null)
I don't know where is the error and why my data is null. If the response succeeds is still gives me null.
This is a postman example
You have an issue with your schema , Your DataLogin class is different of your postman schema , Retrofit is waiting for : fullName, isActive ...., and the response is : header , data .. , you have to create class that contains header as variable of type Header(errors:List<AnotherClass>), data as variable of type Data(data(List<DataLogin>),totalRecord:Int), i would suggest if you use helper website like JSON to Class , parse your postman response there , and he will give you your correct response class but it's will be in java , you have to rewrite the code yourself of just copy paste in android studio and he will convert the code to Kotlin for you. (in the web site , check Source type: JSON)
You have to match the json structure with your data classes if you do not provide a custom adapter to Gson. So if you want to have a result, maybe something like this will work:
data class Response(
#SerializedName("headers") val headers: List<Any>,
#SerializedName("data") val data: Data
)
data class Data(
#SerializedName("data") val data: List<DataLogin>,
#SerializedName("totalRecord") val totalRecord: Int
)
data class DataLogin (
#SerializedName("employeeId") val employeeId : String,
#SerializedName("fullName") val fullName : String,
#SerializedName("loginConfins") val loginConfins : String,
#SerializedName("branchId") val branchId : String,
#SerializedName("isActive") val isActive : String
)
You need to return a Response object from your retrofit call.
Also a few tips about kotlin, Gson works well for Java, but it has some issues with kotlin (about null safety). I use Moshi when the project language is kotlin and it works well with it.
Try to avoid using !! in kotlin because it will cause RuntimeException. There are other ways of checking null and to protect your code from RuntimeExceptions.
I'm attempting to write an invocation handler that uses a map (supplied at runtime) to implement an interface's getters.
This very crudely works. I know the basic types that may be returned, so I'm OK with having a when expression.
I haven't found a way to avoid using the name of the class as the subject of the when expression; is there a better way?
class DynamicInvocationHandler<T>(private val delegate: Map<String, Any>, clzz: Class<T>) : InvocationHandler {
val introspector = Introspector.getBeanInfo(clzz)
val getters = introspector.propertyDescriptors.map { it.readMethod }
override fun invoke(proxy: Any, method: Method, args: Array<Any>?): Any? {
if (method in getters) {
// get the value from the map
val representation = delegate[method.name.substring(3).toLowerCase()]
// TODO need better than name
when (method.returnType.kotlin.simpleName) {
LocalDate::class.simpleName -> {
val result = representation as ArrayList<Int>
return LocalDate.of(result[0], result[1], result[2])
}
// TODO a few other basic types like LocalDateTime
// primitives come as they are
else -> return representation
}
}
return null
}
}
You can use the types instead of the class names in the when statement. After a type is matched, Kotlin smart cast will automatically cast it
Example
val temporal: Any? = LocalDateTime.now()
when (temporal){
is LocalDate -> println("dayOfMonth: ${temporal.dayOfMonth}")
is LocalTime -> println("second: ${temporal.second}")
is LocalDateTime -> println("dayOfMonth: ${temporal.dayOfMonth}, second: ${temporal.second}")
}
when expressions support any type (unlike Java's switch), so you can just use the KClass instance itself:
when (method.returnType.kotlin) {
LocalDate::class -> {
...
}
...
}
I need to supply shared secret attribute to XML, so I decided to add it without exposing it to my API.
#JacksonXmlRootElement(localName = "Request")
data class TestRequest(#JacksonXmlText val request: String)
Here is example POJO, after serializer it looks like
<Request>text</Request>
I need to add attribute to it, like
<Request secret="foobar">text</Request>
I looked to Jackson API and it looks like I need to create custom serializer for root, so
class SessionModule: SimpleModule("Test serializer", PackageVersion.VERSION) {
override fun setupModule(context: SetupContext) {
context.addBeanSerializerModifier(object : XmlBeanSerializerModifier() {
override fun modifySerializer(config: SerializationConfig, beanDesc: BeanDescription, serializer: JsonSerializer<*>): JsonSerializer<*> {
val modifiedSerializer = super.modifySerializer(config, beanDesc, serializer)
if (modifiedSerializer is XmlBeanSerializer) {
println("Registering custom serializer")
return SessionFieldSerializer(modifiedSerializer)
}
return modifiedSerializer
}
})
}
}
And my custom serializer that do nothing
class SessionFieldSerializer: XmlBeanSerializer {
constructor(src: BeanSerializerBase?) : super(src)
constructor(src: XmlBeanSerializerBase?, objectIdWriter: ObjectIdWriter?, filterId: Any?) : super(src, objectIdWriter, filterId)
constructor(src: XmlBeanSerializerBase?, objectIdWriter: ObjectIdWriter?) : super(src, objectIdWriter)
constructor(src: XmlBeanSerializerBase?, toIgnore: MutableSet<String>?) : super(src, toIgnore)
override fun serialize(bean: Any?, g: JsonGenerator?, provider: SerializerProvider?) {
TODO()
}
}
So, all it do is throw not-implemented exception, however even if SessionFieldSerializer() getting instantiated ( I see "Registering custom serializer" message), serialize function is not called.
Test code:
val mapper = XmlMapper()
mapper.registerModule(KotlinModule())
mapper.registerModule(SessionModule())
val request = TestRequest("Foobar")
val test = mapper.writeValueAsString(request)
println(test)
Am I missing something?