Victor Company Victor Company - 2 months ago 56
Android Question

Integrate ZXing in Android Studio

I'll start explaining all the steps I have done and in the end what is the problem.


  1. Download ZXing-2.2 https://code.google.com/p/zxing/downloads/list

  2. Extrac all in zxing-2.2.

  3. Download and install Apache Ant http://www.youtube.com/watch?v=XJmndRfb1TU

  4. With the use of Windows Commandline (Run->CMD) navigate to the extracted directory

  5. In the commandline window - Type 'ant -f core/build.xml' press enter and let Apache work it's magic



At this moment is like Integration ZXing library directly into my Android application

But Wooops, "Buildfile: core\build.xml does not exists! Build failed. ok.
6. Importing ZXing - missing core/build.xml

Now yes, i have my core.jar.


  1. Open Android Studio, File -> Import Project -> Select /android/ in /zxing-2.2/ -> Create project from existing sources -> Project name: andoid -> Source files for... all checked Next -> Libraries (cant do nothing) Next -> Modules (android checked) Next -> SDK 1.7 Next -> Finish



With Project Open -> Build -> Rebuild project

100 errors
19 warnings

File -> project Structure -> Libraries -> Add -> Java -> Select core.jar that i create before and OK -> Library 'core' will be added to the selected modules. (android) OK -> And OK in the Project Structure Dialog.

Build -> Rebuild Project

15 errors
20 warnings

All errors are error: constant expression required and
I see Error in Switch cases of ZXing project in android
I change all switchs for if elses.

0 errors
20 warnings

Ok, now continue:

File -> New project -> zxing_demo Next -> Next -> Blank Activity Next -> Finish

In new project -> File -> Import module -> Search and select /android/ OK -> Create module from existing sources Next -> Next -> Next -> Next -> Finish

Now I can see in the explorer /android/ /zging_demoProject/ and External Libraries

Now i change my code tu scan QR

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.zxing_demo"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="7"
android:targetSdkVersion="16" />
<uses-permission android:name="android.permission.CAMERA"/>
<uses-feature android:name="android.hardware.camera" />
<uses-feature
android:name="android.hardware.camera.autofocus"
android:required="false" />
<uses-feature
android:name="android.hardware.touchscreen"
android:required="false" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.zxing_demo.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:clearTaskOnLaunch="true"
android:stateNotNeeded="true"
android:configChanges="orientation|keyboardHidden"
android:name="com.google.zxing.client.android.CaptureActivity"
android:screenOrientation="landscape"
android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
android:windowSoftInputMode="stateAlwaysHidden" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
<intent-filter >
<action android:name="com.google.zxing.client.android.SCAN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>




MainActivity.java

package com.example.zxing_demo;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent intent = new Intent("com.google.zxing.client.android.SCAN");
intent.putExtra("SCAN_MODE", "QR_CODE_MODE");
startActivityForResult(intent, 0);
}


public void onActivityResult(int requestCode, int resultCode, Intent intent) {
if (requestCode == 0) {
if (resultCode == RESULT_OK) {
String contents = intent.getStringExtra("SCAN_RESULT");
String format = intent.getStringExtra("SCAN_RESULT_FORMAT");
// Handle successful scan
} else if (resultCode == RESULT_CANCELED) {
// Handle cancel
}
}
}

}


Now test, Run -> Debug

And CRASH.

Logcat

08-31 02:58:28.085 20665-20665/com.example.zxing_demo E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.zxing_demo/com.google.zxing.client.android.CaptureActivity}: java.lang.ClassNotFoundException: com.google.zxing.client.android.CaptureActivity
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1891)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992)
at android.app.ActivityThread.access$600(ActivityThread.java:127)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4448)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:823)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: com.google.zxing.client.android.CaptureActivity
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
at android.app.Instrumentation.newActivity(Instrumentation.java:1023)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1882)
... 11 more


I can see in AndroidManifest.xml in this line

android:name="com.google.zxing.client.android.CaptureActivity"


"CaptureActivity" in red and the error say: Cannot resolve symbol 'CaptureActivity'

File -> Project Structure -> Modules -> zxing_demo -> Dependencies -> Add -> Module dependency -> android OK -> Apply and OK

Now CaptureActivity looks good

Debug again

08-31 03:06:58.513 21740-21740/com.example.zxing_demo E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.zxing_demo/com.google.zxing.client.android.CaptureActivity}: java.lang.ClassNotFoundException: com.google.zxing.client.android.CaptureActivity
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1891)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992)
at android.app.ActivityThread.access$600(ActivityThread.java:127)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4448)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:823)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: com.google.zxing.client.android.CaptureActivity
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
at android.app.Instrumentation.newActivity(Instrumentation.java:1023)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1882)
... 11 more


I think i go use the application and intents, but now i want do this work, if someone now whats happen tell me please :D Thanks!

Answer

Okay guys, as my task today was to integrate ZXING into an Android application and there were no good sources for input all over, I will give you a hint what made me be successful - because it turned out to be very easy.

There is a real handy git repository that provides the zxing android library project as an AAR archive.

All you have to do is add this to your build.gradle

repositories {
    jcenter()
}

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

and Gradle does all the magic to compile the code and makes it accessible in your app.

To start the Scanner afterwards, use this class/method: From the Activity:

new IntentIntegrator(this).initiateScan(); // `this` is the current Activity

From a Fragment:

IntentIntegrator.forFragment(this).initiateScan(); // `this` is the current Fragment
// If you're using the support library, use IntentIntegrator.forSupportFragment(this) instead.

There are several customizing options:

IntentIntegrator integrator = new IntentIntegrator(this);
integrator.setDesiredBarcodeFormats(IntentIntegrator.ONE_D_CODE_TYPES);
integrator.setPrompt("Scan a barcode");
integrator.setCameraId(0);  // Use a specific camera of the device
integrator.setBeepEnabled(false);
integrator.setBarcodeImageEnabled(true);
integrator.initiateScan();

They have a sample-project and are providing several integration examples:

If you already visited the link you gonna see that i just copy&pasted the code from the git README. If not, go there to get some more insight and code examples!

Hope to be helpful for future readers. Peace :)