Kotlin Download Image Using Url With Retrofit Example

In this example, I will show you how to download image using url and display download image into imageView. 

Kotlin Download Image Using Url With Retrofit  Example Video

• You can also go through this video explanation.

Kotlin Download Image Using Url With Retrofit Example

Creating a New Project

• So first create a new Android Studio project using Kotlin.
• Once the project is loaded come inside the activity_main.xml and remove the Hello World TextView.

Android studio project screen

Image Url:

https://wallpapersite.com/images/pages/pic_w/6408.jpg

Step 1:

Open build.gradle and add following dependency and rebuild the project.

implementation 'com.squareup.okhttp3:logging-interceptor:3.8.0'
implementation 'com.squareup.retrofit2:retrofit:2.3.0'

Step 2:
Open AndroidManifest.xml and add Internet Permission.
<uses-permission android:name="android.permission.INTERNET"/>
Step 3:
Create new Class:- DataService.kt
DataService.kt
package com.kotlinkatta.imgdowretrofit

import okhttp3.ResponseBody
import retrofit2.Call
import retrofit2.http.GET
import retrofit2.http.Url

public interface DataService {
    @GET
    fun downloadFileUsingUrl(@Url fileUrl: String): Call<ResponseBody>
}
Step 4:
Create new Class:- RetrofitClient.kt
RetrofitClient.kt
package com.kotlinkatta.imgdowretrofit

import okhttp3.OkHttpClient
import okhttp3.logging.HttpLoggingInterceptor
import retrofit2.Retrofit

object RetrofitClient {
    var BASE_URL:String="https://wallpapersite.com"
    val getClient: DataService
        get() {

            val interceptor = HttpLoggingInterceptor()
            interceptor.setLevel(HttpLoggingInterceptor.Level.BODY)

            val client = OkHttpClient.Builder().addInterceptor(interceptor).build()

            val retrofit = Retrofit.Builder()
                .baseUrl(BASE_URL)
                .client(client)
                .build()

            return retrofit.create(DataService::class.java)
        }
}
Step 5:
MainActivity.kt
Add following code into MainActivity.kt.
package com.kotlinkatta.imgdowretrofit

import android.app.ProgressDialog
import android.graphics.BitmapFactory
import android.os.Bundle
import android.widget.ImageView
import androidx.appcompat.app.AppCompatActivity
import okhttp3.ResponseBody
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response

class MainActivity : AppCompatActivity() {

    lateinit var img_display_image : ImageView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        img_display_image = findViewById<ImageView>(R.id.img_display_image)
        funDownloadImage()
    }

    private fun funDownloadImage() {
        @Suppress("DEPRECATION")
        val progressDialog = ProgressDialog(this@MainActivity)
        progressDialog.setTitle("Image is downloading, please wait")
        progressDialog.show()

        val call: Call<ResponseBody> = RetrofitClient.getClient.downloadFileUsingUrl("/images/pages/pic_w/6408.jpg")
        call.enqueue(object : Callback<ResponseBody> {

            override fun onResponse(call: Call<ResponseBody>, response: Response<ResponseBody>) {
                val bytes: ByteArray = response.body()!!.bytes()
                val bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.size)
                img_display_image.setImageBitmap(bitmap)
                progressDialog.dismiss()
            }
            override fun onFailure(call: Call<ResponseBody>, t: Throwable) {
                progressDialog.dismiss()
            }
        })
    }
}
Step 6:
activity_main.xml
Add following code into activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

   <ImageView
       android:id="@+id/img_display_image"
       android:layout_width="match_parent"
       android:layout_height="match_parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>
OutPut: