Web Scraping in Android Application using Kotlin?

Kotlin Apps/ApplicationsMobile DevelopmentAndroid

This example demonstrates how to perform Web Scraping in Android Application using Kotlin.

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:padding="4dp"
   tools:context=".MainActivity">
   <TextView
      android:id="@+id/textView"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_above="@id/btnView"
      android:layout_centerHorizontal="true"
      android:layout_marginBottom="10dp"
      android:padding="4dp"
      android:text="" />
   <Button
      android:id="@+id/btnView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentBottom="true"
      android:layout_centerHorizontal="true"
      android:layout_marginBottom="25sp"
      android:text="Scrap Text from web" />
</RelativeLayout>

Step 3 − Add the following code to src/MainActivity.kt

import android.os.AsyncTask
import android.os.Bundle
import android.widget.Button
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
import org.jsoup.Jsoup
import java.io.IOException
@Suppress("DEPRECATION")
class MainActivity : AppCompatActivity() {
   private lateinit var textView: TextView
   lateinit var button: Button
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      textView = findViewById(R.id.textView)
      button = findViewById(R.id.btnView)
      button.setOnClickListener {
         WebScratch().execute()
      }
   }
   inner class WebScratch : AsyncTask<Void, Void, Void>() {
      private lateinit var words: String
      override fun doInBackground(vararg params: Void): Void? {
      try {
         val document =
            Jsoup.connect("https://www.tutorialspoint.com/css_online_training/index.asp").get()
         words = document.text()
         } catch (e: IOException) {
            e.printStackTrace()
         }
         return null
      }
      override fun onPostExecute(aVoid: Void?) {
         super.onPostExecute(aVoid)
         textView.text = words
      }
   }
}

Step 4 − Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.example.q11">
   <uses-permission android:name="android.permission.INTERNET"/>
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click the Run icon Play Icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen


raja
Published on 09-Jul-2020 12:11:12
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