Ejercicio con Retrofit: Repositorios en Kotlin

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    android:id="@+id/viewRoot"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.appcompat.widget.SearchView
        android:id="@+id/svRepos"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:elevation="7dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintVertical_bias="0.0"
        app:queryHint="paco-portada, ArisGuimera"/>

    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:id="@+id/coordinatorLayout"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/svRepos">

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/rvRepos"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

        </androidx.recyclerview.widget.RecyclerView>

        <com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|right"
            android:layout_margin="24dp"
            android:src="@drawable/ic_baseline_autorenew_24"
            app:layout_anchor="@id/rvRepos"
            app:layout_anchorGravity="bottom|right|end" />

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

/res/values/colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="black">#FF000000</color>
    <color name="white">#FFFFFFFF</color>

    <color name="purple_200">#FFBB86FC</color>
    <color name="purple_500">#FF6200EE</color>
    <color name="purple_700">#FF3700B3</color>
    <color name="teal_200">#FF03DAC5</color>
    <color name="teal_700">#FF018786</color>
</resources>

/res/values/strings.xml

<resources>
    <string name="app_name">Repositorios Kotlin</string>
    <string name="name">Name</string>
    <string name="description">Description</string>
    <string name="createdat">CreatedAt</string>
</resources>

repo_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <androidx.cardview.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <TextView
                android:id="@+id/tvName"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="8dp"
                android:text="@string/name"
                android:textAppearance="@android:style/TextAppearance.Material.Large"
                android:textColor="@color/teal_700" />

            <TextView
                android:id="@+id/tvDescription"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="8dp"
                android:text="@string/description"
                android:textColor="@color/purple_500" />

            <TextView
                android:id="@+id/tvCreatedAt"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="8dp"
                android:text="@string/createdat"
                android:textColor="@color/teal_200" />
        </LinearLayout>
    </androidx.cardview.widget.CardView>
</LinearLayout>

– Creación del RecyclerView y el adapter

Using the RecyclerView

ReposAdapter.java

class ReposAdapter(private val reposList : List<Repo>) : RecyclerView.Adapter<ReposAdapter.RepoViewHolder>() {

    lateinit var onItemClick: ((Repo) -> Unit)
    lateinit var onLongItemClick: ((Repo) -> Unit)

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RepoViewHolder {
        val itemBinding = RepoItemBinding.inflate(LayoutInflater.from(parent.context), parent, false)
        return RepoViewHolder(itemBinding)
    }

    override fun getItemCount(): Int = reposList.size

    override fun onBindViewHolder(holder: RepoViewHolder, position: Int) {
        val item = reposList[position]
        holder.render(item)
    }

    inner class RepoViewHolder(binding: RepoItemBinding) : RecyclerView.ViewHolder(binding.root) {
        private val name = binding.tvName
        private val description = binding.tvDescription
        private val date = binding.tvCreatedAt

        init {
            itemView.setOnClickListener {
                onItemClick.invoke(reposList[layoutPosition])
            }

            itemView.setOnLongClickListener {
                onLongItemClick.invoke(reposList[layoutPosition])
                false
            }
        }

        fun render(repo: Repo) {
            name.text = repo.name
            description.text = repo.description
            date.text = repo.createdAt
        }
    }
}

Patrón Singleton

Ejemplo de Patrón Singleton

Patrones de diseño

– Retrofit

Consuming APIs with Retrofit Cómo consumir una API y procesar la respuesta usando Retrofit Customize Network Timeouts

Define the endpoints:

ApiService.java

interface ApiService {
    // No usar suspend con Call
    // https://stackoverflow.com/questions/75139082/jsonioexception-interfaces-cant-be-instantiated-register-an-instancecreator-o
    @GET("users/{username}/repos")
    fun listRepos(@Path("username") username: String?): Call<ArrayList<Repo>>

    @GET("users/{username}/repos")
    suspend fun listReposResponse(@Path("username") username: String?): Response<ArrayList<Repo>>

    @GET("ficheros/repos.json")
    fun getRepos(): Call<ArrayList<Repo>>

    @GET("ficheros/repos.json")
    suspend fun getReposResponse(): Response<ArrayList<Repo>>
}

Creating the Retrofit instance:

ApiAdapter.java

object ApiAdapter {
    private var API_SERVICE: ApiService? = null
    const val BASE_URL = "https://api.github.com/"

    // const val BASE_URL = "https://dam.org.es/"

    // const val BASE_URL = "http://192.168.0.33/"
    // Añadir al manifiesto
    // android:usesCleartextTraffic="true"

    @get:Synchronized
    val instance: ApiService?

        get() {
            if (API_SERVICE == null) {

                val okHttpClient = OkHttpClient.Builder()
                    .connectTimeout(10, TimeUnit.SECONDS)
                    .readTimeout(10, TimeUnit.SECONDS)
                    .writeTimeout(10, TimeUnit.SECONDS)
                    .build()

                val gson = GsonBuilder()
                    .setDateFormat("dd-MM-yyyy")
                    .create()

                val retrofit = Retrofit.Builder()
                    .baseUrl(BASE_URL)
                    .addConverterFactory(GsonConverterFactory.create(gson))
                    .client(okHttpClient)
                    .build()

                API_SERVICE = retrofit.create(ApiService::class.java)
            }
            return API_SERVICE
        }
}

Accesing the API

Android Kotlin Coroutine with Retrofit

lifecycleScope.launch {
    val response = retrofit.getUsers()
    if (response.isSuccessful) {
        launch(Dispatchers.Main) {
            if (!response.body().isNullOrEmpty()) {
                val recyclerAdapter = response.body()?.let { RecyclerAdapter(it) }
                binding.recyclerView.adapter = recyclerAdapter
            }
        }
    }
}

MainActivity.java

class MainActivity : AppCompatActivity(), View.OnClickListener, SearchView.OnQueryTextListener {

    private lateinit var binding: ActivityMainBinding
    private lateinit var adapter: ReposAdapter
    private val listRepos = mutableListOf<Repo>()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.svRepos.setOnQueryTextListener(this)
        binding.fab.setOnClickListener(this)

        initRecyclerView()

        //getRepos()
    }

    private fun initRecyclerView() {

        adapter = ReposAdapter(listRepos)
        // binding.rvDogs.setHasFixedSize(true)
        binding.rvRepos.layoutManager = LinearLayoutManager(this)
        binding.rvRepos.adapter = adapter
        adapter.onItemClick = {
            showMessage("Single Click: \n" + it.htmlUrl)
            val uri = Uri.parse(it.htmlUrl)
            val intent = Intent(Intent.ACTION_VIEW, uri)
            if (intent.resolveActivity(packageManager) != null)
                startActivity(intent)
            else
                showMessage("No hay un navegador")
        }

        adapter.onLongItemClick = {
            showMessage("Long Click: ${it.name}")
        }
    }

    private fun searchByName(query: String) {
        lateinit var call: Call<ArrayList<Repo>>

        CoroutineScope(Dispatchers.IO).launch {
            call = instance!!.listRepos(query)
            call.enqueue(object : Callback<ArrayList<Repo>> {
                override fun onResponse(
                    call: Call<ArrayList<Repo>>,
                    response: Response<ArrayList<Repo>>
                ) {
                    runOnUiThread {
                        hideKeyboard()
                        if (response.isSuccessful) {
                            // Handle the retrieved post data
                            val repos: ArrayList<Repo> =
                                (response.body() ?: emptyArray<Repo>()) as ArrayList<Repo>
                            listRepos.clear()
                            listRepos.addAll(repos)
                            adapter.notifyDataSetChanged()
                        } else {
                            // Handle error
                            showError(response.code().toString())
                        }
                    }
                }

                override fun onFailure(call: Call<ArrayList<Repo>>, t: Throwable) {
                    // Handle failure
                    runOnUiThread {
                        showMessage(t.toString())
                    }
                }
            })
        }
    }

    private fun searchByNameResponse(query: String) {
        // lateinit var call: Call<ArrayList<Repo>>      

        //CoroutineScope(Dispatchers.IO).launch {
        lifecycleScope.launch {
            try {
                val response = instance!!.listReposResponse(query)
                // val response = instance!!.getReposResponse()
                //runOnUiThread {
                launch(Dispatchers.Main) {
                    hideKeyboard()
                    if (response.isSuccessful) {
                        // Handle the retrieved post data
                        val repos: ArrayList<Repo> =
                            (response.body() ?: emptyArray<Repo>()) as ArrayList<Repo>
                        listRepos.clear()
                        listRepos.addAll(repos)
                        adapter.notifyDataSetChanged()
                    } else {
                        // Handle error
                        showError(response.code().toString())
                    }
                }
            } catch (e: Exception) {
                launch(Dispatchers.Main) {
                    hideKeyboard()
                    showError("Error:\n" + e.message.toString())
                    Log.e("Error", e.message.toString())
                }
            }
        }
        /*
        override fun onFailure(call: Call<ArrayList<Repo>>, t: Throwable) {
            // Handle failure
            runOnUiThread {
                showMessage(t.toString())
            }
        }
         */
    }
    fun getRepos() {

        var call: Call<ArrayList<Repo>> = instance!!.getRepos()

        call.enqueue(object : Callback<ArrayList<Repo>> {
            override fun onResponse(
                call: Call<ArrayList<Repo>>,
                response: Response<ArrayList<Repo>>
            ) {
                // hideKeyboard()
                if (response.isSuccessful) {
                    // Handle the retrieved post data
                    val repos: ArrayList<Repo> =
                        (response.body() ?: emptyArray<Repo>()) as ArrayList<Repo>
                    listRepos.clear()
                    listRepos.addAll(repos)
                    adapter.notifyDataSetChanged()
                } else {
                    // Handle error
                    showError(response.code().toString())
                }
            }

            override fun onFailure(call: Call<ArrayList<Repo>>, t: Throwable) {
                // Handle failure
                showMessage(t.toString())
                Log.e("Error", t.toString())
            }
        })
    }

    fun showMessage(message: String) {
        Toast.makeText(this, "$message", Toast.LENGTH_SHORT).show()
    }

    fun showError(message: String) {
        Toast.makeText(this, "Ha ocurrido un error:\n $message", Toast.LENGTH_SHORT).show()
    }

    override fun onQueryTextSubmit(query: String): Boolean {

        if (!query.isNullOrEmpty())
            // searchByName(query.lowercase())
            searchByNameResponse(query.lowercase())

        return true
    }

    override fun onQueryTextChange(newText: String?): Boolean {
        return true
    }

    private fun hideKeyboard() {
        val imm = getSystemService(INPUT_METHOD_SERVICE) as InputMethodManager
        imm.hideSoftInputFromWindow(binding.viewRoot.windowToken, 0)
    }

    override fun onClick(v: View?) {
        if (v === binding.fab) {
            val user = binding.svRepos.query.toString()
            if (user.isNullOrEmpty())
                showMessage("Introduzca un usuario")
            else
                searchByName(user)
            //searchByNameResponse(query.lowercase())
        }
    }

}