Android Retrofit Example Kotlin

1/  Create a new project .

main_activity.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:background="@color/white"
    >
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recelerView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />

</RelativeLayout>

2/ Add dependencies

////////////////Retrofit in android////////////
implementation ("com.squareup.retrofit2:converter-gson:2.8.1") //Add Library for retrofit here
implementation ("com.squareup.retrofit2:retrofit:2.9.0")
//////////////////picasso in android/////////
implementation ("com.squareup.picasso:picasso:2.8")
// OkHttp logging interceptor (optional)
implementation ("com.squareup.okhttp3:logging-interceptor:4.10.0")

3/  Create a new Kotlin Class.

>>> DataModel.kt

package com.bangladeshplayer.bangladeshplayer

data class DataModel(
    val player_name: String,
    val player_catagory: String,
    val player_age: String,
    val player_avater: String

)

4/  Create a new Interface 

>>>RetrofitService

package com.bangladeshplayer.bangladeshplayer

import retrofit2.http.GET

interface RetrofitService {
    @GET("playerinfo.json")     ////Use your api endPoint
    suspend fun getAllplayer(): List<DataModel>
}

5/  Create a new object.

>>>RetrofitInstance.kt

package com.bangladeshplayer.bangladeshplayer

import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory

object RetrofitInstance {
    private const val BASE_URL = "http://codewithbiozid10.atwebpages.com/"////put your base Url
    val api: RetrofitService by lazy {
        Retrofit.Builder()
            .baseUrl(BASE_URL)
            .addConverterFactory(GsonConverterFactory.create())
            .build()
            .create(RetrofitService::class.java)
    }
}

6/  Create a new Adapter.

>>>PlayerAdapter.kt

package com.bangladeshplayer.bangladeshplayer

import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.squareup.picasso.Picasso

class PlayerAdapter(private val dataList: List<DataModel>) : RecyclerView.Adapter<PlayerAdapter.PalyerViewHolder>() {

    class PalyerViewHolder(view: View) : RecyclerView.ViewHolder(view) {
        val player_name: TextView = view.findViewById(R.id.player_name)
        val player_catagory: TextView = view.findViewById(R.id.player_catagory)
        val player_age: TextView = view.findViewById(R.id.player_age)
        val player_avater: ImageView = view.findViewById(R.id.player_avater)
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): PalyerViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(R.layout.item_layout, parent, false)
        return PalyerViewHolder(view)
    }

    override fun onBindViewHolder(holder: PalyerViewHolder, position: Int) {
        val dataModel = dataList[position]
        holder.player_name.text = dataModel.player_name
        holder.player_catagory.text = dataModel.player_catagory
        holder.player_age.text = dataModel.player_age
        holder.player_age.text = dataModel.player_age
        val imageurl: String=dataModel.player_avater
        Picasso.get()
            .load(""+imageurl)
            .placeholder(R.drawable.ic_launcher_background) // Image shown while loading
            .error(R.drawable.ic_launcher_background)       // Image shown on error
            .into(holder.player_avater)


    }

    override fun getItemCount() = dataList.size
}

7/  Create a new Layout Resource File.

<?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">

    <LinearLayout
        android:id="@+id/contentLay"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:background="@drawable/bottom_shade"
        android:paddingBottom="10dp"
        android:layout_margin="10dp"
        android:clickable="true"
        android:foreground="?attr/selectableItemBackground"

        >

        <ImageView
            android:id="@+id/player_avater"
            android:layout_width="180dp"
            android:layout_height="250dp"
            android:scaleType="centerCrop"
            android:layout_margin="5dp"
            android:src="@mipmap/ic_launcher"
            />

        <LinearLayout
            android:layout_marginStart="5dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:gravity="left|center"

            >
            <TextView
                android:id="@+id/player_name"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text=""
                android:textStyle="bold"
                android:textSize="25sp"
                android:layout_marginTop="5dp"
                android:textColor="@color/black"

                />
            <TextView
                android:id="@+id/player_catagory"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text=""
                android:textSize="23sp"
                android:layout_marginTop="3dp"
                android:textStyle="bold"
                android:textColor="#009688"


                />
            <TextView
                android:id="@+id/player_age"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text=""
                android:textSize="22sp"
                android:layout_marginTop="3dp"
                android:textStyle="bold|italic"
                android:textColor="@color/black"


                />

        </LinearLayout>


    </LinearLayout>

</LinearLayout>

8/  MainActivity.kt

package com.bangladeshplayer.bangladeshplayer

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext

class MainActivity : AppCompatActivity() {

    private lateinit var recyclerView: RecyclerView
    private lateinit var adapter: PlayerAdapter


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        recyclerView=findViewById(R.id.recelerView)

        recyclerView = findViewById(R.id.recelerView)
        recyclerView.layoutManager = LinearLayoutManager(this)
        DataRequest()

    }




    private fun DataRequest(){


        CoroutineScope(Dispatchers.IO).launch {
            try {
                val datamodel = RetrofitInstance.api.getAllplayer()
                withContext(Dispatchers.Main) {
                    adapter = PlayerAdapter(datamodel)
                    recyclerView.adapter = adapter
                }
            } catch (e: Exception) {
                e.printStackTrace()
            }
        }
}
}

9/  Internet Permissoin .

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:networkSecurityConfig="@xml/network_security_config"
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.BangladeshPlayer"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

10/  In a Optional XML file create if you need.

if your use free api or http Api.

this is are

>>>>network_security_config.xml

<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">codewithbiozid10.atwebpages.com</domain>
    </domain-config>
</network-security-config>