Develop Reference

Debugging Android in custom libraries

I have just created a react-native library using react-native-create-library and imported it into my master react-native project.
There are some issues I'm having because (honestly) I lack the knowledge.
The problem is that there are no errors (using logcat) and I don't know how I can debug the android part of my imported library.
Example
public class RNZappsCameraModule extends ReactContextBaseJavaModule
implements ActivityEventListener {
#ReactMethod
public void myJavascriptMethod() {
// I want a breakpoint here
// cameraIntent initialization happens here
try
{
currentActivity.startActivityForResult(cameraIntent, requestCode);
}
catch (ActivityNotFoundException e)
{
e.printStackTrace();
}
}
#Override
public void onActivityResult(Activity activity, int requestCode, int resultCode, Intent data)
{
// I want a breakpoint here
}
}
The camera intent starts fine, but I believe onActivityResult is never hit.
I know I could log everything and read it, but that won't explain why the result is never returned to my app since there are no errors in the first place.
Google and the official RN documentation are not being my friend at the moment, so please put me on the right track.

Found it.
No rocket science here. I don't know how I managed to do it in the end...
Anyheeew, to give this question a reasonable answer for passers-by...
First off, you need a react-native (master) project in order to actually run your library in a react-native context.
So create it and import your library. The easiest way to do this is by pushing your library into a git repository and adding your library in the package.json of you master project like this:
"react-native-your-package": "git+https://your-git-url-here",
Now install it: npm install react-native-your-package
In order to debug your library:
Open the android project of your react-native project in Android Studio
In menu => view => Tool window, click Build Variants
The new window displays the build types for you project and loaded modules
Click the Build Variant dropdown next to the module you want to debug and select 'debug'
Debug the master Android project
In the projects view, you can expand your module and place breakpoints where ever you like
Click the debug button and fix errors you never head of

How to setup alljoyn sdk in android?

I am trying to setup two android devices to communicate with each other through wifi. Some of the links I have gone through suggest alljoyn sdk in order to accomplish this.
There is an sdk download but there is no documentation for how to setup environment.

Here is how to set up an AllJoyn SDK development environment with android studio:
Download the SDK from this page. Go for Android Core SDK - release (or debug).
Create a new blank android project.
Create directory <project>/app/src/main/jniLibs and <project>/app/src/main/jniLibs/armeabi.
From alljoyn-15.09.00-rel/java/jar copy alljoyn.jar and from alljoyn-15.09.00-rel/java/lib copy liballjoyn_java.so. The directory to copy from might differ depending on the current version and your release/debug choice.
Put alljoyn.jar in /jniLibs and put liballjoyn_java.so in /jniLibs/armeabi. Should look like this
Right click project -> Open Module Settings -> app -> Dependencies.
With the green [+] button, add a file dependency.
Navigate to <project>/app/src/main/jniLibs/alljoyn.jar and select that jar.
This will add a line in your gradle (compile files('src/main/jniLibs/alljoyn.jar')) that will allow for code completion etc.
In the file where you want to use alljoyn code, include this snippet
/* Load the native alljoyn_java library. */
static {
System.loadLibrary("alljoyn_java");
}
for example:
public class MainActivity extends AppCompatActivity {
/* Load the native alljoyn_java library. */
static {
System.loadLibrary("alljoyn_java");
}
#Override
public void onCreate(Bundle savedInstanceState) {
...
}
}
You can now use the alljoyn SDK. Import classes with
import org.alljoyn.bus.BusAttachment;
import org.alljoyn.bus.BusException;
import org.alljoyn.bus.BusListener;
etc.
If you're more of an eclipse guy, check this official documentation page on how to setup an eclipse environment.

Could not find class XXX referenced from method XXX.<YYY>

I'm working on a libGDX project and I have a class called CheerVArachnids that has another inline class which is an event listener. When I run this project on the desktop it works fine. BUT when I run on my Android device, it can't find that inline class and I get the following error:
Could not find class 'com.bbj.cva.CheerVArachnids$PlaceUnitListener', referenced from method com.bbj.cva.CheerVArachnids.<init>
Here are the important parts of my class:
package com.bbj.cva;
public class CheerVArachnids implements ApplicationListener {
class PlaceUnitListener implements EventSubscriber<PlaceUnitEvent> {
#Override
public void onEvent(PlaceUnitEvent event)
{
//
}
}
public CheerVArachnids() {
EventBus.subscribe(PlaceUnitEvent.class, new PlaceUnitListener());
EventBus.subscribe(RemoveScreenObjectEvent.class,
new RemoveScreenObjectListener());
}
}
Any ideas why on Android, at runtime it can't find that inline class?

Since some ADT-Version you have to set which libraries / projects should be exported too.
Project-Propiertes -> Java Build Path -> Order and Export -> Check your Sources and other Libraries you are using.
Do these Export-Settings for your Core- and Android-Project.
Then it should work fine on Android.

In my case, everything worked fine until I installed the new updates for the SDK and Eclipse.
I got an error: "Could not find class..."
I found solution in another stackoverflow site.
I have a similar problem when using external jar (in my case openCSV). The reason I had a problem was due to a change in ADT 17 (or above). What I needed to do to resolve the problem was
In Eclipse go to Properties -> Java build path -> Order and export.
Mark my jar.
Move jar to top of the list.
The solution was found in the following page which reference to a very good article.

First you should: import XXX(Class).java,
If you added external library jar file import them to the LIB folder.
After that:
Right Click to your Project -> Properties -> Java Build Path -> Order and Export(tab) -> select All -> press OK -> Clean your Project.
Hope this solve this issue

Facebook Android SDK source will not compile with Eclipse Indigo

After finally getting the Android Facebook SDK to properly import thanks to this, I found that eclipse does not recognize the override of onclick in FbDialog.java:
mCrossImage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mListener.onCancel();
FbDialog.this.dismiss();
}
});
Nor does it recognize the overrides of onServiceConnected and onServiceDisconnected in the TokenRefreshServiceConnection implementation of ServiceConnection
#Override
public void onServiceConnected(ComponentName className, IBinder service) {
messageSender = new Messenger(service);
refreshToken();
}
#Override
public void onServiceDisconnected(ComponentName arg) {
serviceListener.onError(new Error("Service disconnected"));
// We returned an error so there's no point in
// keeping the binding open.
mAuthActivity.unbindService(TokenRefreshServiceConnection.this);
}
All three methods say, in the warning, that the method must override a superclass method. I have not modified the code at all yet. I checked that Eclipse recognizes the types as the same ones in the respective superclasses, and I have tried pressing control-shift-o to organize the imports, which was a fix suggested in this answer for a similar problem.
These overrides are part of the SDK, not any separate project. I set up the project to use Android SDK 2.2 as was shown on Facebook's instructions, and 4.0.3, which should be, theoretically, compatible with all previous versions. I have yet to get Facebook's own code to work. As a side note, is there a jar I can use instead? It would make this much easier.

Guessing your Project Properties -> Java Compiler Compiler compliance level is set to 1.5, not 1.6 (or higher).
Change this.
Why is javac failing on #Override annotation

The lazy, fast and easy fix is to remove the #Override annotations. The correct fix is to check that the project compiles to Java 1.5 or above, to use "fix project properties" from Eclipse, and possibly to check that the Facebook library project uses the same Android SDK for compiling against, as your project.

Problems importing an Android project into Eclipse

I reinstalled my computer and tried now to import my Android project into the workspace.
(File -> Import -> General -> Existing Project into Workspace)
But now I have got a strange error.
bNormal.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
gotoNextQuestion();
}
});
In the second line (#Override) eclipse always tells me there is an error:
/* Multiple markers at this line
- implements android.view.View.OnClickListener.onClick
- The method onClick(View) of type new View.OnClickListener(){} must override a superclass Method */
This happens everywhere, where #Override is used.
I already tried to Android-Tools -> Fix Project Settings and Project -> Clean.
I hope somebody can help me with this strange problem.
Thanks, Mark

It is because the language level is set to 5.0. Change it to 6, and all will work fine. Don't know where to set it eclipse, but in Idea it's File - Project Structure - Project Language level
It happens because OnClickListener is an interface and in 5th Java #Override can not be applied to a method implementation.

Your android SDK is probably not in the same path. Fix that in your eclipse settings.