Using ZXing library in Android Studio

BarcodeGenerator.java

package com.dotincorp.android.util;

import android.graphics.Bitmap;
import android.graphics.Color;
import android.os.AsyncTask;
import android.util.Log;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;

/**
 * Created by seongho on 2017. 3. 20..
 */

public class BarcodeGenerator extends AsyncTask<String, String, Bitmap>{

    public BarcodeResponse delegate = null;

    private BarcodeFormat mBarcodeType = BarcodeFormat.CODE_128;
    private int mImageWidth = 0;
    private int mImageHeigth = 0;

    @Override
    protected Bitmap doInBackground(String... params) {
        return getImage(params[0]);
    }

    @Override
    protected void onPostExecute(Bitmap bitmap) {

        if(delegate!=null){
            delegate.postResult(mBarcodeType, bitmap);
        }else{
            Log.e("BarcodeGenerator", "You have not assigned BarcodeResponse delegate");
        }

    }

    public Bitmap getImage(String barcodeNumber){

        MultiFormatWriter gen = new MultiFormatWriter();

        try {

            final int WIDTH = mImageWidth;
            final int HEIGHT = mImageHeigth;
            BitMatrix bytemap = gen.encode(barcodeNumber, mBarcodeType, WIDTH, HEIGHT);
            Bitmap bitmap = Bitmap.createBitmap(WIDTH, HEIGHT, Bitmap.Config.ARGB_8888);
            for (int i = 0 ; i < WIDTH ; ++i)
                for (int j = 0 ; j < HEIGHT ; ++j) {
                    bitmap.setPixel(i, j, bytemap.get(i,j) ? Color.BLACK : Color.WHITE);
                }

            return bitmap;

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }


    public int getImageHeigth() {
        return mImageHeigth;
    }

    public void setImageHeigth(int mImageHeigth) {
        this.mImageHeigth = mImageHeigth;
    }

    public BarcodeFormat getBarcodeType() {
        return mBarcodeType;
    }

    public void setBarcodeType(BarcodeFormat mBarcodeType) {
        this.mBarcodeType = mBarcodeType;
    }

    public int getImageWidth() {
        return mImageWidth;
    }

    public void setImageWidth(int mImageWidth) {
        this.mImageWidth = mImageWidth;
    }

}

BarcodeResponse.java

package com.dotincorp.android.util;

import android.graphics.Bitmap;

import com.google.zxing.BarcodeFormat;

/**
 * Created by seongho on 2017. 3. 20..
 */

public interface BarcodeResponse {
    void postResult(BarcodeFormat barcodeType , Bitmap asyncResult);
}

build.gradle

repositories { 
	jcenter() 
} 

dependencies { 
	compile 'com.journeyapps:zxing-android-embedded:3.0.2@aar' 
	compile 'com.google.zxing:core:3.2.0' 
}

MainActivity.java

import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.widget.ImageView;

import com.dotincorp.android.util.BarcodeGenerator;
import com.dotincorp.android.util.BarcodeResponse;
import com.google.zxing.BarcodeFormat;

/**
 * Created by seongho on 2017. 3. 20..
 */

public class MainActivity extends Activity implements BarcodeResponse {
  
      ImageView mBarcodeImage;
  
  
      @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setLayout();
    }

    private void setLayout(){
        setContentView(R.layout.activity_barcode);
        mBarcodeImage = (ImageView) findViewById(R.id.barcode_image);
    }

    @Override
    protected void onStart() {
        super.onStart();

        // EAM_13
        BarcodeGenerator barcodeGenerator = new BarcodeGenerator();
        barcodeGenerator.delegate = this;
        barcodeGenerator.setBarcodeType(BarcodeFormat.EAN_13);
        barcodeGenerator.setImageWidth(320);
        barcodeGenerator.setImageHeigth(180);
        barcodeGenerator.execute("5901234123457");
    }

    @Override
    public void postResult(BarcodeFormat barcodeType, Bitmap asyncResult) {
        if(barcodeType == BarcodeFormat.EAN_13){
            mBarcodeImage.setImageBitmap(asyncResult);
        }
    }
}