Example Android app build.gradle, showing desugaring support to enable jsoup on API level 21

activity_load_gz.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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/textView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="16dp"
            android:text="Loading..."
            android:textSize="16sp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    </ScrollView>

</androidx.constraintlayout.widget.ConstraintLayout>

build.gradle

apply plugin: 'com.android.application'

allprojects {
    repositories {
        maven {
            url "https://maven.google.com"
        }
        mavenCentral()
    }
}
android {
    defaultConfig {
        // Required when setting minSdkVersion to 20 or lower
        multiDexEnabled true
    }

    compileOptions {
        compileSdkVersion 33
        coreLibraryDesugaringEnabled true
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    defaultConfig {
        applicationId "org.jsoup.benchmark.android"
        minSdkVersion 21
        targetSdkVersion 33
    }

    buildTypes {
        release {
            minifyEnabled false
        }
    }
    namespace 'org.jsoup.benchmark.android'
    lint {
        abortOnError false
    }

}

dependencies {
    coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs_nio:2.1.4'

    implementation (
            'com.squareup:otto:1.3.8',
            'com.android.support:support-core-utils:28.0.0',
            'com.android.support:support-annotations:28.0.0',
            files('/Users/jhy/.m2/repository/org/jsoup/jsoup/1.19.1-SNAPSHOT/jsoup-1.19.1-SNAPSHOT.jar'),
            //'org.jsoup:jsoup:1.15.3',
            //'org.jsoup:jsoup:1.11.3'

            'com.google.android.material:material:1.4.0',
    )
}

LoadGzActivity.java

package org.jsoup.benchmark.android;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.text.method.ScrollingMovementMethod;
import android.util.Log;
import android.widget.TextView;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class LoadGzActivity extends Activity {
    // Tests for Android Desugar NIO. https://github.com/jhy/jsoup/issues/2270

    private TextView textView;
    private static final String TAG = "LoadGzActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_load_gz);
        textView = findViewById(R.id.textView);
        textView.setMovementMethod(new ScrollingMovementMethod());

        ExecutorService executor = Executors.newSingleThreadExecutor();
        executor.execute(() -> {
            try {
                File gzFile = getGzFile(getApplicationContext());
                Path gzPath = gzFile.toPath();
                Document doc = Jsoup.parse(gzPath, "UTF-8");

                runOnUiThread(() -> textView.setText(doc.outerHtml()));
            } catch (Throwable e) {
                Log.e(TAG, "Error loading or parsing file", e);
                runOnUiThread(() -> textView.setText("Error loading or parsing file: " + e.getMessage()));
            }
        });
        executor.shutdown();
    }

    public static File getGzFile(Context context) throws IOException {
        InputStream in = context.getAssets().open("unicode-chars.html.bin");
        File outFile = new File(context.getFilesDir(), "unicode-chars.html.gz");
        if (!outFile.exists()) {
            // Copy once
            try (OutputStream out = Files.newOutputStream(outFile.toPath())) {
                byte[] buffer = new byte[8192];
                int len;
                while ((len = in.read(buffer)) != -1) {
                    out.write(buffer, 0, len);
                }
            } finally {
                in.close();
            }
        }
        return outFile;
    }


}