CODEWITHSUNDEEP
androidkotlin
pepperlove
pepperlove

Reputation: 275

Convert HttpURLConnection String Response to Kotlin Objects without third party libraries

    GlobalScope.launch(Dispatchers.Main) {
        val result = httpGet("https://jsonplaceholder.typicode.com/todos/?userId=1")
        
        
        var gson = Gson()
        val itemType = object : TypeToken<List<Todo>>() {}.type
        val todoList = gson.fromJson<List<Todo>>(result, itemType)

        insertData(todoList)

        val todoRecyclerView = findViewById<RecyclerView>(R.id.recyclerView)
        val adapter = TodoItemAdapter(todoList)
        todoRecyclerView.adapter = adapter
        todoRecyclerView.layoutManager = LinearLayoutManager(applicationContext, LinearLayoutManager.VERTICAL, false)

 
    }

private suspend fun httpGet(myURL: String?): String  =

    withContext(Dispatchers.IO){
        val inputStream: InputStream
        val result:String

        // create URL
        val url:URL = URL(myURL)

        // create HttpURLConnection
        val conn:HttpURLConnection = url.openConnection() as HttpURLConnection

        // make GET request to the given URL
        conn.connect()

        // receive response as inputStream
        inputStream = conn.inputStream

        // convert inputstream to string
        result = inputStream?.bufferedReader().use { it?.readText() } ?: "Did not work!"
        result
}

I am using the above code to connect to an API and retrieve some data and convert it to a kotlin objects. I am using Gson currently for the conversion. Is there any other way rather than using third party libraries to do the same.

Response from the API.

[ { "userId": 1, "id": 1, "title": "delectus aut autem", "completed": false }, { "userId": 1, "id": 2, "title": "quis ut nam facilis et officia qui", "completed": false }, { "userId": 1, "id": 3, "title": "fugiat veniam minus", "completed": false }, { "userId": 1, "id": 4, "title": "et porro tempora", "completed": true } ]

Kotlin Object:

@Entity(tableName = "todo")
data class Todo(
    @PrimaryKey(autoGenerate = true)
    val localId: Long = 0L,
    @SerializedName("userId")
    val userId: Long = 0L,
    @SerializedName("id")val id: Long = 0L,
    @SerializedName("title")val title: String = "",
    @SerializedName("completed")val completed: Boolean = false
)

Upvotes: 1

Views: 516

Answers (1)

ferini
ferini

Reputation: 1958

Well, if you want to avoid 3rd party libraries, you can write your own json parser, but I would advise against it. Why not leverage work of others, that is widely used and tested and instead try and reinvent the wheel?

One thing to note is that Gson does not understand kotlin nullable types well, so maybe Moshi or kotlinx.serialization would serve you better.

Upvotes: 1

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