buildscript {
    
    repositories {
        google()
        jcenter()

        mavenCentral()
    }

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.conekta.conektatokenizeandroid"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}


dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    implementation 'org.jbundle.util.osgi.wrapped:org.jbundle.util.osgi.wrapped.org.apache.http.client:4.1.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'

  
    implementation 'io.conekta:conektasdk:2.2'
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_form"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/cardNumberLabel"
        android:layout_width="90dp"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/cardNumber"
        android:layout_alignParentTop="true"
        android:text="Card holder:" />

    <EditText
        android:id="@+id/cardNumber"
        android:layout_width="300dp"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:text="4242424242424242" />

    <TextView
        android:id="@+id/cardHolderLabel"
        android:layout_width="90dp"
        android:layout_height="wrap_content"
        android:layout_below="@id/cardNumberLabel"
        android:layout_alignBottom="@+id/cardHolder"
        android:text="Card: number:" />

    <EditText
        android:id="@+id/cardHolder"
        android:layout_width="300dp"
        android:layout_height="wrap_content"
        android:layout_below="@id/cardNumberLabel"
        android:layout_alignParentRight="true"
        android:text="Daniel Diner" />

    <TextView
        android:id="@+id/expirationLabel"

        android:layout_width="90dp"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/year"
        android:layout_below="@id/cardHolderLabel"
        android:text="Expiration:" />

    <EditText
        android:id="@+id/month"
        android:layout_width="80dp"
        android:layout_height="wrap_content"
        android:layout_below="@+id/cardHolderLabel"
        android:layout_toEndOf="@+id/expirationLabel"
        android:layout_toRightOf="@+id/expirationLabel"
        android:text="01" />

    <EditText
        android:id="@+id/year"
        android:layout_width="80dp"
        android:layout_height="wrap_content"
        android:layout_below="@+id/cardHolder"
        android:layout_toEndOf="@+id/month"
        android:layout_toRightOf="@+id/month"
        android:text="2020" />

    <TextView
        android:id="@+id/cvcLabel"
        android:layout_width="90dp"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/cvcNumber"
        android:layout_below="@id/year"
        android:text="CVV:" />

    <EditText
        android:id="@+id/cvcNumber"
        android:layout_width="50dp"
        android:layout_height="wrap_content"
        android:layout_below="@+id/month"
        android:layout_toEndOf="@+id/cvcLabel"
        android:layout_toRightOf="@+id/cvcLabel"
        android:text="123" />

    <TextView
        android:id="@+id/outputLabel"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="OUTPUT:"
        android:layout_below="@id/cvcNumber"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <Button
        android:id="@+id/btnTokenize"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/outputLabel"
        android:text="Tokenize" />

</RelativeLayout>

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import io.conekta.conektasdk.Conekta;
import io.conekta.conektasdk.Card;
import io.conekta.conektasdk.Token;
import org.json.JSONObject;

 private Button btnTokenize;
    private TextView outputLabel;
    private EditText cardNumber;
    private EditText cardHolder;
    private EditText cvcNumber;
    private EditText month;
    private EditText year;
    private Activity activity = this;

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);



        Conekta.setPublicKey("key_CBsGarr9nE2Ueds5V5kV7Pw");
        Conekta.setApiVersion("0.3.0"); //Set api version (optional)
        Conekta.collectDevice(activity); //Collect device*/

        outputLabel = (TextView) findViewById(R.id.outputLabel);
        btnTokenize = (Button) findViewById(R.id.btnTokenize);
        cardHolder = (EditText) findViewById(R.id.cardHolder);
        cardNumber = (EditText) findViewById(R.id.cardNumber);
        month = (EditText) findViewById(R.id.month);
        year = (EditText) findViewById(R.id.year);
        cvcNumber = (EditText) findViewById(R.id.cvcNumber);


        btnTokenize.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                Card card = new Card(cardHolder.getText().toString(),
                        cardNumber.getText().toString(),
                        cvcNumber.getText().toString(),
                        month.getText().toString(),
                        year.getText().toString());


                Token token = new Token(activity);



                token.onCreateTokenListener(new Token.CreateToken() {
                    @Override
                    public void onCreateTokenReady(JSONObject data) {
                        try {
                            outputLabel.setText("Token id: " + data.getString("id"));
                        } catch (Exception error) {
                            outputLabel.setText("Error: " + error.toString());
                        }
                    }
                });
                token.create(card);//Create token
            }
        });

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.conekta.conektatokenizeandroid">

    <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">

        <uses-library android:name ="org.apache.http.legacy" android:required ="false"/>

        <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>

(...)
<uses-permission android:name="android.permission.INTERNET" />

<application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        
 (...)       

  // Your code....
  import io.conekta.conektasdk.Conekta;
  import io.conekta.conektasdk.Card;
  import io.conekta.conektasdk.Token;
  import org.json.JSONObject;
  // Your code...
  
  private Activity activity = this;

  Conekta.setPublicKey("key_KJysdbf6PotS2ut2"); //Set public key
  Conekta.setApiVersion("0.3.0"); //Set api version (optional)
  Conekta.collectDevice(activity); //Collect device

  Card card = new Card("Josue Camara", "4242424242424242", "332", "11", "2017");
  Token token = new Token(activity);

  token.onCreateTokenListener( new Token.CreateToken(){
    @Override
    public void onCreateTokenReady(JSONObject data) {
      try {
        //TODO: Create charge
        Log.d("Token::::", data.getString("id"));
      } catch (Exception err) {
      //TODO: Handle error
        Log.d("Error: " + err.toString());
      }
    }
  });

  token.create(card);//Create token
  // Your code below....