How to parse HTML in Android using Kotlin?

This example demonstrates how to parse HTML in Android 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="8dp"
   tools:context=".MainActivity">
   <Button
      android:id="@+id/btnParseHTML"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="30dp"
      android:text="Get website" />
   <TextView
      android:textColor="@android:color/background_dark"
      android:id="@+id/textView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@id/btnParseHTML"
      android:layout_centerHorizontal="true"
      android:text="Result"
      android:textSize="12sp"
      android:textStyle="bold" />
</RelativeLayout>

Step 3 − Add the given dependency in the build.gradle (Module: app)

implementation 'org.jsoup:jsoup:1.11.2'

Step 4 − Add the following code to src/MainActivity.kt

import android.os.Bundle
import android.widget.Button
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
import org.jsoup.Jsoup
import org.jsoup.nodes.Document
import org.jsoup.select.Elements
import java.io.IOException
class MainActivity : AppCompatActivity() {
   lateinit var button: Button
   lateinit var textView: TextView
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      textView = findViewById(R.id.textView)
      button = findViewById(R.id.btnParseHTML)
      button.setOnClickListener {
         getHtmlFromWeb()
      }
   }
   private fun getHtmlFromWeb() {
      Thread(Runnable {
         val stringBuilder = StringBuilder()
         try {
            val doc: Document = Jsoup.connect("http://www.tutorialspoint.com/").get()
            val title: String = doc.title()
            val links: Elements = doc.select("a[href]")
            stringBuilder.append(title).append("\n")
            for (link in links) {
               stringBuilder.append("\n").append("Link :
               ").append(link.attr("href")).append("\n").append("Text : ").append(link.text())
            }
         } catch (e: IOException) {
            stringBuilder.append("Error : ").append(e.message).append("\n")
         }
         runOnUiThread { textView.text = stringBuilder.toString() }
      }).start()
   }
}

Step 5 − 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="app.com.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 from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen

Azhar

Published on 09-Jul-2020 11:09:38