[android] Integrating the ZXing library directly into my Android application

I'm writing this in mere desperation :) I've been assigned to make a standalone barcode scanner (as a proof of concept) to an Android 1.6 phone.

For this i've discovered the ZXing library.

I've googled, read related topics here on StackOverflow used common sence and so forth. Nothing seemed to have helped, and i just can't punch a hole on this mentale blockade :/

I know it to be possible, to use the lib, and create your own standalone barcode scanner. I've read that using the "Barcode Scanner" provided by the Zxing folks, is by far the easiest solution (via Intent). Unfortunately this is not an option, and a standalone app is desired.

So to sum up my problem :

1. How to integrate ZXing source lib into my Android Code project through Eclipse?
2. When integrated ... how to make use of the lib, to "load" the scanning function?
3. A step to step guide is almost prefered because i just started working in Eclipse.

I've tried to make my code project dependant of the Android folder from the ZXing source folder. When i do so, a handfull errors emerge, mostly concerning 'org.apache' (??)

I just can't figure it out ... so a few hints would be most helpfull.

In advance, thank you :)

The

compile 'com.google.zxing:core:2.3.0'

unfortunately didn't work for me.

This is what worked for me:

dependencies {
   compile 'com.journeyapps:zxing-android-embedded:3.0.1@aar'
   compile 'com.google.zxing:core:3.2.0'
}

Please find the link here: https://github.com/journeyapps/zxing-android-embedded

Put

compile 'com.google.zxing:core:2.3.0' 

into your Gradle dependencies. As easy as that. Prior to using Android Studio and Gradle build system.

Here is a step-by-step guide on how to generate and display QR code using ZXing library without having to install the third-party application. Note: you don't have to build ZXing with ANT or any other build tool. The file core.jar is available in the released zip archive (read below).

1. Download the latest release of ZXing. -- (ZXing-*.zip)
2. Extract this zip archive and find core.jar under core/ directory.
3. If you are using Eclipse IDE, drag and drop core.jar to the libs directory of your Android project. When asked, select Copy.
4. Copy the two classes given below (Contents.java & QRCodeEncoder.java) to the main package of your Android project.
5. Create an ImageView item in your Activity to display the generated QR code in if you don't have one already. An example is given below:
6. Use the code snippet below to generate the QR code in Bitmap format and display it in an ImageView.

Here is an ImageView element to add to your Activity layout XML file:

<ImageView 
    android:id="@+id/qrCode"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="50dp"
    android:layout_centerHorizontal="true"/>

Code snippet:

// ImageView to display the QR code in.  This should be defined in 
// your Activity's XML layout file
ImageView imageView = (ImageView) findViewById(R.id.qrCode);

String qrData = "Data I want to encode in QR code";
int qrCodeDimention = 500;

QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(qrData, null,
        Contents.Type.TEXT, BarcodeFormat.QR_CODE.toString(), qrCodeDimention);

try {
    Bitmap bitmap = qrCodeEncoder.encodeAsBitmap();
    imageView.setImageBitmap(bitmap);
} catch (WriterException e) {
    e.printStackTrace();
}

Here is Contents.java

//
// * Copyright (C) 2008 ZXing authors
// * 
// * Licensed under the Apache License, Version 2.0 (the "License");
// * you may not use this file except in compliance with the License.
// * You may obtain a copy of the License at
// * 
// * http://www.apache.org/licenses/LICENSE-2.0
// * 
// * Unless required by applicable law or agreed to in writing, software
// * distributed under the License is distributed on an "AS IS" BASIS,
// * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// * See the License for the specific language governing permissions and
// * limitations under the License.
// 

import android.provider.ContactsContract;

public final class Contents {
    private Contents() {
    }

    public static final class Type {

     // Plain text. Use Intent.putExtra(DATA, string). This can be used for URLs too, but string
     // must include "http://" or "https://".
        public static final String TEXT = "TEXT_TYPE";

        // An email type. Use Intent.putExtra(DATA, string) where string is the email address.
        public static final String EMAIL = "EMAIL_TYPE";

        // Use Intent.putExtra(DATA, string) where string is the phone number to call.
        public static final String PHONE = "PHONE_TYPE";

        // An SMS type. Use Intent.putExtra(DATA, string) where string is the number to SMS.
        public static final String SMS = "SMS_TYPE";

        public static final String CONTACT = "CONTACT_TYPE";

        public static final String LOCATION = "LOCATION_TYPE";

        private Type() {
        }
    }

    public static final String URL_KEY = "URL_KEY";

    public static final String NOTE_KEY = "NOTE_KEY";

    // When using Type.CONTACT, these arrays provide the keys for adding or retrieving multiple phone numbers and addresses.
    public static final String[] PHONE_KEYS = {
            ContactsContract.Intents.Insert.PHONE, ContactsContract.Intents.Insert.SECONDARY_PHONE,
            ContactsContract.Intents.Insert.TERTIARY_PHONE
    };

    public static final String[] PHONE_TYPE_KEYS = {
            ContactsContract.Intents.Insert.PHONE_TYPE,
            ContactsContract.Intents.Insert.SECONDARY_PHONE_TYPE,
            ContactsContract.Intents.Insert.TERTIARY_PHONE_TYPE
    };

    public static final String[] EMAIL_KEYS = {
            ContactsContract.Intents.Insert.EMAIL, ContactsContract.Intents.Insert.SECONDARY_EMAIL,
            ContactsContract.Intents.Insert.TERTIARY_EMAIL
    };

    public static final String[] EMAIL_TYPE_KEYS = {
            ContactsContract.Intents.Insert.EMAIL_TYPE,
            ContactsContract.Intents.Insert.SECONDARY_EMAIL_TYPE,
            ContactsContract.Intents.Insert.TERTIARY_EMAIL_TYPE
    };
}

And QRCodeEncoder.java

/*
 * Copyright (C) 2008 ZXing authors
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import android.provider.ContactsContract;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.telephony.PhoneNumberUtils;

import java.util.Collection;
import java.util.EnumMap;
import java.util.HashSet;
import java.util.Map;

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

public final class QRCodeEncoder {
    private static final int WHITE = 0xFFFFFFFF;
    private static final int BLACK = 0xFF000000;

    private int dimension = Integer.MIN_VALUE;
    private String contents = null;
    private String displayContents = null;
    private String title = null;
    private BarcodeFormat format = null;
    private boolean encoded = false;

    public QRCodeEncoder(String data, Bundle bundle, String type, String format, int dimension) {
        this.dimension = dimension;
        encoded = encodeContents(data, bundle, type, format);
    }

    public String getContents() {
        return contents;
    }

    public String getDisplayContents() {
        return displayContents;
    }

    public String getTitle() {
        return title;
    }

    private boolean encodeContents(String data, Bundle bundle, String type, String formatString) {
        // Default to QR_CODE if no format given.
        format = null;
        if (formatString != null) {
            try {
                format = BarcodeFormat.valueOf(formatString);
            } catch (IllegalArgumentException iae) {
                // Ignore it then
            }
        }
        if (format == null || format == BarcodeFormat.QR_CODE) {
            this.format = BarcodeFormat.QR_CODE;
            encodeQRCodeContents(data, bundle, type);
        } else if (data != null && data.length() > 0) {
            contents = data;
            displayContents = data;
            title = "Text";
        }
        return contents != null && contents.length() > 0;
    }

    private void encodeQRCodeContents(String data, Bundle bundle, String type) {
        if (type.equals(Contents.Type.TEXT)) {
            if (data != null && data.length() > 0) {
                contents = data;
                displayContents = data;
                title = "Text";
            }
        } else if (type.equals(Contents.Type.EMAIL)) {
            data = trim(data);
            if (data != null) {
                contents = "mailto:" + data;
                displayContents = data;
                title = "E-Mail";
            }
        } else if (type.equals(Contents.Type.PHONE)) {
            data = trim(data);
            if (data != null) {
                contents = "tel:" + data;
                displayContents = PhoneNumberUtils.formatNumber(data);
                title = "Phone";
            }
        } else if (type.equals(Contents.Type.SMS)) {
            data = trim(data);
            if (data != null) {
                contents = "sms:" + data;
                displayContents = PhoneNumberUtils.formatNumber(data);
                title = "SMS";
            }
        } else if (type.equals(Contents.Type.CONTACT)) {
            if (bundle != null) {
                StringBuilder newContents = new StringBuilder(100);
                StringBuilder newDisplayContents = new StringBuilder(100);

                newContents.append("MECARD:");

                String name = trim(bundle.getString(ContactsContract.Intents.Insert.NAME));
                if (name != null) {
                    newContents.append("N:").append(escapeMECARD(name)).append(';');
                    newDisplayContents.append(name);
                }

                String address = trim(bundle.getString(ContactsContract.Intents.Insert.POSTAL));
                if (address != null) {
                    newContents.append("ADR:").append(escapeMECARD(address)).append(';');
                    newDisplayContents.append('\n').append(address);
                }

                Collection<String> uniquePhones = new HashSet<String>(Contents.PHONE_KEYS.length);
                for (int x = 0; x < Contents.PHONE_KEYS.length; x++) {
                    String phone = trim(bundle.getString(Contents.PHONE_KEYS[x]));
                    if (phone != null) {
                        uniquePhones.add(phone);
                    }
                }
                for (String phone : uniquePhones) {
                    newContents.append("TEL:").append(escapeMECARD(phone)).append(';');
                    newDisplayContents.append('\n').append(PhoneNumberUtils.formatNumber(phone));
                }

                Collection<String> uniqueEmails = new HashSet<String>(Contents.EMAIL_KEYS.length);
                for (int x = 0; x < Contents.EMAIL_KEYS.length; x++) {
                    String email = trim(bundle.getString(Contents.EMAIL_KEYS[x]));
                    if (email != null) {
                        uniqueEmails.add(email);
                    }
                }
                for (String email : uniqueEmails) {
                    newContents.append("EMAIL:").append(escapeMECARD(email)).append(';');
                    newDisplayContents.append('\n').append(email);
                }

                String url = trim(bundle.getString(Contents.URL_KEY));
                if (url != null) {
                    // escapeMECARD(url) -> wrong escape e.g. http\://zxing.google.com
                    newContents.append("URL:").append(url).append(';');
                    newDisplayContents.append('\n').append(url);
                }

                String note = trim(bundle.getString(Contents.NOTE_KEY));
                if (note != null) {
                    newContents.append("NOTE:").append(escapeMECARD(note)).append(';');
                    newDisplayContents.append('\n').append(note);
                }

                // Make sure we've encoded at least one field.
                if (newDisplayContents.length() > 0) {
                    newContents.append(';');
                    contents = newContents.toString();
                    displayContents = newDisplayContents.toString();
                    title = "Contact";
                } else {
                    contents = null;
                    displayContents = null;
                }

            }
        } else if (type.equals(Contents.Type.LOCATION)) {
            if (bundle != null) {
                // These must use Bundle.getFloat(), not getDouble(), it's part of the API.
                float latitude = bundle.getFloat("LAT", Float.MAX_VALUE);
                float longitude = bundle.getFloat("LONG", Float.MAX_VALUE);
                if (latitude != Float.MAX_VALUE && longitude != Float.MAX_VALUE) {
                    contents = "geo:" + latitude + ',' + longitude;
                    displayContents = latitude + "," + longitude;
                    title = "Location";
                }
            }
        }
    }

    public Bitmap encodeAsBitmap() throws WriterException {
        if (!encoded) return null;

        Map<EncodeHintType, Object> hints = null;
        String encoding = guessAppropriateEncoding(contents);
        if (encoding != null) {
            hints = new EnumMap<EncodeHintType, Object>(EncodeHintType.class);
            hints.put(EncodeHintType.CHARACTER_SET, encoding);
        }
        MultiFormatWriter writer = new MultiFormatWriter();
        BitMatrix result = writer.encode(contents, format, dimension, dimension, hints);
        int width = result.getWidth();
        int height = result.getHeight();
        int[] pixels = new int[width * height];
        // All are 0, or black, by default
        for (int y = 0; y < height; y++) {
            int offset = y * width;
            for (int x = 0; x < width; x++) {
                pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;
            }
        }

        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }

    private static String guessAppropriateEncoding(CharSequence contents) {
        // Very crude at the moment
        for (int i = 0; i < contents.length(); i++) {
            if (contents.charAt(i) > 0xFF) { return "UTF-8"; }
        }
        return null;
    }

    private static String trim(String s) {
        if (s == null) { return null; }
        String result = s.trim();
        return result.length() == 0 ? null : result;
    }

    private static String escapeMECARD(String input) {
        if (input == null || (input.indexOf(':') < 0 && input.indexOf(';') < 0)) { return input; }
        int length = input.length();
        StringBuilder result = new StringBuilder(length);
        for (int i = 0; i < length; i++) {
            char c = input.charAt(i);
            if (c == ':' || c == ';') {
                result.append('\\');
            }
            result.append(c);
        }
        return result.toString();
    }
}

I have recently used google mobile vision in both ios and android. I highly recommend to use Google Barcode Scan. It is pretty responsive with any orientation and processing time is pretty fast. It is called Google Mobile Vision.

The Barcode Scanner API detects barcodes in real time in any orientation. You can also detect and parse several barcodes in different formats at the same time.

https://developers.google.com/vision/

https://codelabs.developers.google.com/codelabs/bar-codes/#0

2020 UPDATE: Just add this to your Gradle file. It works perfectly!

repositories {
   jcenter()
}
implementation 'me.dm7.barcodescanner:zxing:1.9.13'

Since some of the answers are outdated, I would like to provide my own -

To integrate ZXing library into your Android app as suggested by their Wiki, you need to add 2 Java files to your project:

• IntentIntegrator.java
• IntentResult.java

Then in Android Studio add the following line to build.gradle file:

dependencies {
    ....
    compile 'com.google.zxing:core:3.2.1'
}

Or if still using Eclipse with ADT-plugin add core.jar file to the libs subdirectory of your project (here fullscreen Windows and fullscreen Mac):

Finally add this code to your MainActivity.java:

public void scanQRCode(View v) {
    IntentIntegrator integrator = new IntentIntegrator(MainActivity.this);
    integrator.initiateScan(IntentIntegrator.QR_CODE_TYPES);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
    IntentResult result = 
        IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);
    if (result != null) {
        String contents = result.getContents();
        if (contents != null) {
            showDialog(R.string.result_succeeded, result.toString());
        } else {
            showDialog(R.string.result_failed,
                getString(R.string.result_failed_why));
        }
    }
}

private void showDialog(int title, CharSequence message) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle(title);
    builder.setMessage(message);
    builder.setPositiveButton(R.string.ok_button, null);
    builder.show();
}

The resulting app will ask to install and start Barcode Scanner app by ZXing (which will return to your app automatically after scanning):

Additionally, if you would like to build and run the ZXing Test app as inspiration for your own app:

Then you need 4 Java files from GitHub:

• BenchmarkActivity.java
• BenchmarkAsyncTask.java
• BenchmarkItem.java
• ZXingTestActivity.java

And 3 Jar files from Maven repository:

• core.jar
• android-core.jar
• android-integration.jar

(You can build the Jar files yourself with mvn package - if your check out ZXing from GitHub and install ant and maven tools at your computer).

Note: if your project does not recognize the Jar files, you might need to up the Java version in the Project Properties:

Having issues building with ANT? Keep reading

If ant -f core/build.xml says something like:

Unable to locate tools.jar. Expected to find it in
C:\Program Files\Java\jre6\lib\tools.jar

then set your JAVA_HOME environment variable to the proper java folder. I found tools.jar in my (for Windows):

C:\Program Files\Java\jdk1.6.0_21\lib

so I set my JAVA_HOME to:

C:\Progra~1\Java\jdk1.6.0_25

the reason for the shorter syntax I found at some site which says:

"It is strongly advised that you choose an installation directory that does not include spaces in the path name (e.g., do NOT install in C:\Program Files). If Java is installed in such a directory, it is critical to set the JAVA_HOME environment variable to a path that does not include spaces (e.g., C:\Progra~1); failure to do this will result in exceptions thrown by some programs that depend on the value of JAVA_HOME."

I then relaunched cmd (important because DOS shell only reads env vars upon launching, so changing an env var will require you to use a new shell to get the updated value)

and finally the ant -f core/build.xml worked.

I tried all possible ways to achieve this and then I discovered Minified version of xZing by JourneyApps. I have ported that for eclipse and shared on GitHub.

If you are using eclipse use this project:-

https://github.com/hiteshsahu/XZing-Barcode-Scanner-Minified-Eclipse

If you are using Studio use this project :-

https://github.com/journeyapps/zxing-android-embedded

Advantages

1. Inbuilt Barcode scanner in your App do not required to install third party apps using playstore.

2. You dont need to get confused between Core,Android client etc jars simply drop this packages and relevent layouts in your project and you are good to go. Only Jar required is com.google.zxing:core:3.2.0 which you can download from

   http://mvnrepository.com/artifact/com.google.zxing/core/3.2.0

3. No need to add tons of packages see images below for comparison

Before :-

After :-

4. Most important part is they are highly customizable ie. you can add flash light, use it in fragment and support orientation change.

5. You can use this Capture activity in Cordova App for barcode scanneing.

your capture activity in app manifest would look like this

  <activity
            android:name="com.journeyapps.barcodescanner.CaptureActivity"
            android:clearTaskOnLaunch="true"
            android:configChanges="orientation|keyboardHidden"
            android:exported="false"
            android:screenOrientation="fullSensor"
            android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
            android:windowSoftInputMode="stateAlwaysHidden" >
            <intent-filter>
                <action android:name="com.google.zxing.client.android.SCAN" />

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>

and plugin will look like this

public class BarcodeScanner extends CordovaPlugin {
    public static final int REQUEST_CODE = 0x0ba7c0de;

    private static final String SCAN = "scan";
    private static final String CANCELLED = "cancelled";
    private static final String FORMAT = "format";
    private static final String TEXT = "text";
    private static final String SCAN_INTENT = "com.google.zxing.client.android.SCAN";

    private static final String LOG_TAG = "BarcodeScanner";

    private CallbackContext callbackContext;

    /**
     * Constructor.
     */
    public BarcodeScanner() {


    }

    /**
     * Executes the request.
     *
     * This method is called from the WebView thread. To do a non-trivial amount of work, use:
     *     cordova.getThreadPool().execute(runnable);
     *
     * To run on the UI thread, use:
     *     cordova.getActivity().runOnUiThread(runnable);
     *
     * @param action          The action to execute.
     * @param args            The exec() arguments.
     * @param callbackContext The callback context used when calling back into JavaScript.
     * @return                Whether the action was valid.
     *
     * @sa https://github.com/apache/cordova-android/blob/master/framework/src/org/apache/cordova/CordovaPlugin.java
     */
    @Override
    public boolean execute(String action, JSONArray args, CallbackContext callbackContext) {
        this.callbackContext = callbackContext;
        if (action.equals(SCAN)) {
            scan(args);
        } else {
            return false;
        }
        return true;
    }

    /**
     * Starts an intent to scan and decode a barcode.
     */
    public void scan(JSONArray args) {
        Intent intentScan = new Intent(SCAN_INTENT);
        intentScan.addCategory(Intent.CATEGORY_DEFAULT);

        // add config as intent extras
        if(args.length() > 0) {

            JSONObject obj;
            JSONArray names;
            String key;
            Object value;

            for(int i=0; i<args.length(); i++) {

                try {
                    obj = args.getJSONObject(i);
                } catch(JSONException e) {
                    Log.i("CordovaLog", e.getLocalizedMessage());
                    continue;
                }

                names = obj.names();
                for(int j=0; j<names.length(); j++) {
                    try {
                        key = names.getString(j);
                        value = obj.get(key);

                        if(value instanceof Integer) {
                            intentScan.putExtra(key, (Integer)value);
                        } else if(value instanceof String) {
                            intentScan.putExtra(key, (String)value);
                        }

                    } catch(JSONException e) {
                        Log.i("CordovaLog", e.getLocalizedMessage());
                        continue;
                    }
                }
            }

        }

        // avoid calling other phonegap apps
        intentScan.setPackage(this.cordova.getActivity().getApplicationContext().getPackageName());

        this.cordova.startActivityForResult((CordovaPlugin) this, intentScan, REQUEST_CODE);
    }

    /**
     * Called when the barcode scanner intent completes.
     *
     * @param requestCode The request code originally supplied to startActivityForResult(),
     *                       allowing you to identify who this result came from.
     * @param resultCode  The integer result code returned by the child activity through its setResult().
     * @param intent      An Intent, which can return result data to the caller (various data can be attached to Intent "extras").
     */
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent intent) {
        if (requestCode == REQUEST_CODE) {
            if (resultCode == Activity.RESULT_OK) {
                JSONObject obj = new JSONObject();
                try {
                    obj.put(TEXT, intent.getStringExtra("SCAN_RESULT"));
                    obj.put(FORMAT, intent.getStringExtra("SCAN_RESULT_FORMAT"));
                    obj.put(CANCELLED, false);
                } catch (JSONException e) {
                    Log.d(LOG_TAG, "JSONException "+e.getMessage());
                }
                this.callbackContext.success(obj);
            } else if (resultCode == Activity.RESULT_CANCELED) {
                this.callbackContext.success("");
            } else {
                this.callbackContext.error("Technical Problem");
            }
        }
    }
}

Happy Integration !!

Why use an external lib, when google play services (since version 7.8.0) includes a barcode decoder.

The zxing guys have made it easier to create a android project with 1.7. Its not as painful as it used to be. This is a quick blog for anyone who would like to create a zxing project for android quickly.

• Checkout the zxing sources from zxing.org
• Create a Android project on your eclipse
• Delete main.xml
• Right click on “src” directory and hit import. Browse to the following directories in the order mentioned. As you add them for import one by one, ensure that you have the src directory in the edit field of the import wizard. And that you select only the “com” directory on the left directory tree. Do not select src.
• core
• android-integration
• android
• Ensure that your android sdk version is 9, anything lesser and androidmanifest.xml will cry.
• Strings.xml in one of the languages will crib, just put a / before the ‘ character

A android project for zxing 1.7 (June 20 checkout).

http://www.4shared.com/file/bFx8Y5Ys/zXingJune2010.html (NOT AVAILABLE ANYMORE)

I just wrote a method, which decodes generated bar-codes, Bitmap to String.

It does exactly what is being requested, just without the CaptureActivity...

Therefore, one can skip the android-integration library in the build.gradle :

dependencies {
    // https://mvnrepository.com/artifact/com.google.zxing
    compile('com.google.zxing:core:3.3.0')
    compile('com.google.zxing:android-core:3.3.0')
}

The method as following (which actually decodes generated bar-codes, within a jUnit test):

import android.graphics.Bitmap;

import com.google.zxing.BinaryBitmap;
import com.google.zxing.LuminanceSource;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.NotFoundException;
import com.google.zxing.RGBLuminanceSource;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.Result;

protected String decode(Bitmap bitmap) {

    MultiFormatReader reader = new MultiFormatReader();
    String barcode = null;

    int[] intArray = new int[bitmap.getWidth() * bitmap.getHeight()];
    bitmap.getPixels(intArray, 0, bitmap.getWidth(), 0, 0, bitmap.getWidth(), bitmap.getHeight());
    LuminanceSource source = new RGBLuminanceSource(bitmap.getWidth(), bitmap.getHeight(), intArray);
    BinaryBitmap binary = new BinaryBitmap(new HybridBinarizer(source));

    try {

        Result result = reader.decode(binary);
        // BarcodeFormat format = result.getBarcodeFormat(); 
        // ResultPoint[] points = result.getResultPoints();
        // byte[] bytes = result.getRawBytes(); 
        barcode = result.getText();

    } catch (NotFoundException e) {
        e.printStackTrace();
    }
    return barcode;
}

Have you seen the wiki pages on the zxing website? It seems you might find GettingStarted, DeveloperNotes and ScanningViaIntent helpful.

Much Easier approach.

Just include dependency in your app level gradle file

compile 'com.journeyapps:zxing-android-embedded:3.0.1@aar'
compile 'com.google.zxing:core:3.2.0'  

Define one button in your xml file and and write below code in Java file in OnCreate()and inside the OnClick listener of button

new IntentIntegrator(this).initiateScan();

And write below code after OnCreate() of the Java file

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
    if(result != null) {
        if(result.getContents() == null) {
            Log.d("MainActivity", "Cancelled scan");
            Toast.makeText(this, "Cancelled", Toast.LENGTH_LONG).show();
        } else {
            Log.d("MainActivity", "Scanned");
            String st_scanned_result = result.getContents();
            Toast.makeText(this, "Scanned: " + result.getContents(), Toast.LENGTH_LONG).show();

        }
    }

}

Step by step to setup zxing 3.2.1 in eclipse

1. Download zxing-master.zip from "https://github.com/zxing/zxing"
2. Unzip zxing-master.zip, Use eclipse to import "android" project in zxing-master
3. Download core-3.2.1.jar from "http://repo1.maven.org/maven2/com/google/zxing/core/3.2.1/"
4. Create "libs" folder in "android" project and paste cor-3.2.1.jar into the libs folder
5. Click on project: choose "properties" -> "Java Compiler" to change level to 1.7. Then click on "Android" change "Project build target" to android 4.4.2+, because using 1.7 requires compiling with Android 4.4
6. If "CameraConfigurationUtils.java" don't exist in "zxing-master/android/app/src/main/java/com/google/zxing/client/android/camera/". You can copy it from "zxing-master/android-core/src/main/java/com/google/zxing/client/android/camera/" and paste to your project.
7. Clean and build project. If your project show error about "switch - case", you should change them to "if - else".
8. Completed. Clean and build project.
9. Reference link: Using ZXing to create an android barcode scanning app

If you just need the core.jar from zxing, you can skip that process and get the pre-built JARs from the GettingStarted wiki page

Latest ZXing (2.2) doesn't have core.jar under core folder but you can obtain the core.jar from the zxing Maven repository here

This library works like a charm, easy to integrate and use. https://github.com/dm77/barcodescanner