Develop Reference

Including javax persistence in a Cordova/Android project

I am trying to incorporate ObjectBox in my hybrid Cordova/Android project. By dint of some trial and error I have managed to figure out two of the steps involved.
The app level build.gradle file has to be modified to include the ObjectBox Gradle plugin classpath "io.objectbox:objectbox-gradle-plugin:2.5.0"
Define a build-extras.gradle file to "apply" the ObjectBox plugin ext.postBuildExtras = {apply plugin: 'io.objectbox'}
The next step according to the ObjectBox docs is to define at least one Entity class
However, the issue here is that I need to import the javax.persistence.* classes into the project. It is not clear to me how I do this. I have run into suggestions along the lines of including
compile group: 'javax.persistence', name: 'javax.persistence-api', version: '2.2'
in the dependencies section of the app level build.gradle file. However, this causes gradle to complain that it does not know the compile() function. I'd be much obliged to anyone who might be able to tell me how this should be done.

For the benefit of anyone running into this thread - you can download the JAR file for javax.persistence here. Place this line in the folder src/android/libsof your custom plugin and then modify plugin.xmlwith the line
<lib-file src='src/android/libs/name-of-javax-persistence.jar'/>

Android studio 3.1 not recognizing jar annotation processing

I'm trying to implement my own annotation processor in my android studio project. All is working well and compiling until I add this simple line to build.gradle dependencies block:
dependencies {
.
.
.
annotationProcessor(':processor')
}
At that point I get this error when compiling:
Could not find :processor:. Required by:
project :app Search in build.gradle files
I've followed endless tutorials and nothing seems to help. I've just recently upgraded to AS 3.1 and thinking maybe it relates?
Here is the project structure: (mind you - here I add the annotation processor as a jar file. I've also attached an image trying to do it as a different module and same result)
Here is a different I'm trying to add it - creating the annotation processor in the same project with a different module and still no go:
Some extra info in pics...
Project structure:
app.build:
processor.build:
annotation:
MainActivity:
Processor implementation:

If you have everything inside the same artifact, — annotation processor, it's annotations and library classes, used by processor users, Android Gradle plugin requires you to declare two dependencies on the same artifact:
annotationProcessor project(':processor')
compile project(':processor')
or
annotationProcessor files('libs/processor.jar')
compile files('libs/processor.jar')
Note, that such setup might become unsupported in future. It is advisable to split your processor in separate module and make it depend on the rest of code. After doing so you will be able to declare dependencies like this:
annotationProcessor project(':processor') // processor-only jar
compile project(':processor-api') // annotations and classes for user code

How to access aar file, in libs, from Main

I spent the last three days trying to read an .aar in Android Studio and I just can't figure it out.
My project view looks like this:
--- AnApplication
----------------------.gradle
-----------------------.idea
----------------------- app
-------------------------------- build
-------------------------------- libs
---------------------------------------- cube5-debug.aar
(...)
I want to access a class inside cube5-debug.aar from my main activity.
I know the class is there in the .aar file.
I don't know the precise import line I must write at the start of my main.
I have tried import com.company_cube.cube5 (the package of the project where I generated my .aar) and many other variants.
I don't know if Android Studio is recognizing the file as a library. However, the files sync with the gradle successfully.
(For context, the project where I generated the .aar was made by Unity, by exporting a Unity project into an Android one, and then generating the .aar from that one; the goal was to use this .aar file as a library in a second Android Studio project - the one I am talking about in this post)
I am patiently waiting for any help you can give me. Thanks
EDIT: To import the .aar, I followed the images of this small post:
Importing .aar in android Studio
And solved the error the post reports by putting the .aar in the libs folder like Daniel Nugent said. However, when I try to write, in the Main:
Intent intent = new Intent(getApplicationContext(),UnityPlayerActivity.class);
AS doesn't recognize UnitPlayerActivity. This class is inside the .aar file supposedly. Before making the aar in my first AS project, it was here:
cube5->libs->unity-classes.jar->com.unity3d.player->UnityPlayerActivity
When I open the .aar with Winrar, and open unity-classes.jar with a text editor, I see a almost everything as encoded symbols.
I'm not sure it is normal. Any idea?
EDIT 2: I think I know where the error is: when I import my .aar, I get an IDE fatal error. I don't know how to solve it, so if you can, please check the post I made about it:
IDE fatal error on importing .aar

For android Studio 2.3.3 you can use
repositories {
flatDir {
dirs 'libs' //this way we can find the .aar file in libs folder
}
}
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
compile(name: 'cube5-debug', ext: 'aar')
}
in the app level build.gradle. I did't check it for AS 3.0.

Add .aar file to your app by doing:
in project build.gradle
allprojects {
repositories {
flatDir {
dirs 'libs'
}
}
}
in app build.gradle
dependencies {
compile(name:'cube5-debug', ext:'aar')
}

So I managed to solve it. The .aar file I talked about was exported with AS, after I imported an Unity project into AS. I did this in order to use the Unity program inside AS. However, this gives error for some versions of Unity and AS. I installed Unity 5.5.0f3 and an older version of AS, and everything worked fine.
Note1: if you aim to install that Unity version, you will be prompted with a requirement of some windows 10 tool, which you must get (I cannot remember the name). I did it by downloading windows 10 install and installing only that tool, which comes with the package.
Note2: I made the program from Unity work inside AS but only because it was a simple program. I later wanted to do an Augmented Reality App in Unity, and use it in AS, but it cannot be done apparently. Evertyting works fine until I import the .aar into AS, and a class in that .aar library gets unresolved ("Video player”). This should have to do with the AR camera class, which AS does not recognize. I ended up creating a AR app with Unity, another app in AS, and from the AS app, calling the Unity app with two lines of code, whenever necessary. To return to the AS app, now in background, I simple click the back button, which is recognized by the Unity app (if you make code in Unity for it) and makes it destroy itself, returning to the AS app.

Using jackson-dataformat-xml on android

I'm strugling with using jackson-dataformat-xml on android
I have some very basic code that works fine on oracle jre
JacksonXmlModule module = new JacksonXmlModule();
module.setDefaultUseWrapper(false);
XmlMapper xmlMapper = new XmlMapper(module);
First I tried official documentation adapted for gradle (by me, not sure if done correctly):
compile 'com.fasterxml.jackson.core:jackson-core:2.5.4'
compile 'com.fasterxml.jackson.core:jackson-annotations:2.5.4'
compile 'com.fasterxml.jackson.core:jackson-databind:2.5.4'
compile 'com.fasterxml.jackson.dataformat:jackson-dataformat-xml:2.5.4'
compile 'org.codehaus.woodstox:woodstox-core-asl:4.4.1'
compile 'javax.xml.stream:stax-api:1.0-2'
Result: gradle fails build time about bundling corelibraries into an application
...
:app:preDexDebug
trouble processing "javax/xml/stream/EventFilter.class":
Ill-advised or mistaken usage of a core class (java.* or javax.*)
when not building a core library.
...
2nd attempt trying to follow Sean's answer
(Basicly he repackages corelibs with prefix names and rebuilds jackson-dataformat-xml to use the prefixed names)
compile 'com.fasterxml.jackson.core:jackson-core:2.1.2'
compile 'com.fasterxml.jackson.core:jackson-annotations:2.1.2'
compile 'com.fasterxml.jackson.core:jackson-databind:2.1.2'
// Repackaged XML-specific libraries
compile 'edu.usf.cutr.android.xml:jackson-dataformat-xml-android:2.1.2'
compile 'edu.usf.cutr.android.xml:stax2-api-android:3.1.1'
compile 'edu.usf.cutr.android.xml:stax-api-android:1.0-2'
compile 'edu.usf.cutr.android.xml:aalto-xml-android:0.9.8'
And build time failed on duplicates
Duplicate files copied in APK META-INF/services/com.fasterxml.jackson.core.ObjectCodec
so added:
packagingOptions {
...
exclude 'META-INF/services/com.fasterxml.jackson.core.JsonFactory'
exclude 'META-INF/services/com.fasterxml.jackson.core.ObjectCodec'
}
When adding the exclusions it builds and deploys, but fails runtime on below stackdump (AFAIK it cant find the SAX provider, even tho it is added to the classpath to my understanding)
edu.usf.cutr.javax.xml.stream.FactoryConfigurationError: Provider com.bea.xml.stream.MXParserFactory not found
at edu.usf.cutr.javax.xml.stream.FactoryFinder.newInstance(FactoryFinder.java:72)
at edu.usf.cutr.javax.xml.stream.FactoryFinder.find(FactoryFinder.java:176)
at edu.usf.cutr.javax.xml.stream.FactoryFinder.find(FactoryFinder.java:92)
at edu.usf.cutr.javax.xml.stream.XMLInputFactory.newInstance(XMLInputFactory.java:136)
at com.fasterxml.jackson.dataformat.xml.XmlFactory.<init>(XmlFactory.java:97)
at com.fasterxml.jackson.dataformat.xml.XmlFactory.<init>(XmlFactory.java:85)
at com.fasterxml.jackson.dataformat.xml.XmlFactory.<init>(XmlFactory.java:82)
at com.fasterxml.jackson.dataformat.xml.XmlMapper.<init>(XmlMapper.java:46)
What is the proper way to move forward on either #1 or #2?

Number 2 is the correct approach (Android doesn't like it when you include classes in the official Java package namespace - but then again, I wrote the original answer so I'm biased ;) ).
I believe the FactoryConfigurationError: Provider com.bea.xml.stream.MXParserFactory not found error is due to a bug in the Android build tools. In previous versions of ADT for Eclipse and Gradle plugin < 0.7.0 the /META-INF/* files are stripped from the JARs during the build process. It seems like >= v0.7.0 shouldn't have the problem according to Google, but from others' reports it sounds like it still may be problematic, and could potentially remove the META-INF/services/javax.xml.stream.XMLInputFactory file, which is required for the platform to register Aalto.
Try the workaround mentioned in AOSP issue 59658 comment 22:
right click on /src/main (where you have /java and /res folders),
select New > Folder > Java Resources Folder,
click Finish (do not change Folder Location),
right click on new /resources folder,
select New > Directory
enter "META-INF" (without quotes),
right click on /resources/META-INF folder,
select New > Directory
enter "services" (without quotes)
copy any file you need into /resources/META-INF/services
For you, in step 10 above you'd need to copy this file into /resources/META-INF/services. In case the file link is broken in the future, the name of the file is javax.xml.stream.XMLInputFactory and it consists of a single line:
com.fasterxml.aalto.stax.InputFactoryImpl
EDIT
If you get a "Error:duplicate files during packaging of APK... Path in archive: META-INF/services/javax.xml.stream.XMLInputFactory", you can try telling Gradle to keep the first occurrence with:
android {
packagingOptions {
pickFirst 'META-INF/services/javax.xml.stream.XMLInputFactory'
}
}
EDIT 2
This bug may be affecting "pickFirst". Please make sure you're running the latest version of Android Studio, and update your local tools and Android Gradle plugin to make sure you're running the most recent version of the tools. This may be fixed in Android Studio 1.3 RC1.

I have attempted to add XmlPull support to jackson xml. Find the forked project here:
https://github.com/finvu/jackson-dataformat-xml
Currently, only supported for version 2.9.6. (clone the branch jackson-dataformat-xml-2.9.6-XmlPull)
Sorry, I am not able to provide detailed documentation due to time constraints. If you have knowledge of git and maven to pull a specific branch and build the jar, then it should be relatively easy.

To those who will be in need of this in the future:
first integrate Jitpack in Your Android app, following their instructions:
https://jitpack.io/
Then paste teh GitHub url of jackson-dataformat-xml on Jitpack sites' corresponding text box. GitHub url is:
https://github.com/FasterXML/jackson-dataformat-xml.
That's it! Enjoy the result. :)

How to create Android library in Android Studio [duplicate]

How do I create an Android Library Project (e.g. com.myapp.lib1) and the application project (e.g. com.myapp.app) and make the build system include com.myapp.lib1 on the application project?
I went to the Project Structure -> Modules -> My App project and added a dependency to the lib project. IntelliJ now can recognize classes from the lib project when used in the app project, but when I run the app project, there are errors like:
Gradle: error: package com.myapp.lib1 does not exist

I wonder why there is no example of stand alone jar project.
In eclipse, we just check "Is Library" box in project setting dialog.
In Android studio, I followed this steps and got a jar file.
Create a project.
open file in the left project menu.(app/build.gradle): Gradle Scripts > build.gradle(Module: XXX)
change one line: apply plugin: 'com.android.application' -> 'apply plugin: com.android.library'
remove applicationId in the file: applicationId "com.mycompany.testproject"
build project: Build > Rebuild Project
then you can get aar file: app > build > outputs > aar folder
change aar file extension name into zip
unzip, and you can see classes.jar in the folder.
rename and use it!
Anyway, I don't know why google makes jar creation so troublesome in android studio.

To create a library:
File > New Module
select Android Library
To use the library add it as a dependancy:
File > Project Structure > Modules > Dependencies
Then add the module (android library) as a module dependency.
Run your project. It will work.

Google’s Gradle Plugin recommended way for configuring your gradle files to build multiple projects has some shortcomings If you have multiple projects depending upon one library project, this post briefly explain Google’s recommended configuration, its shortcomings, and recommend a different way to configure your gradle files to support multi-project setups in Android Studio:
An alternative multiproject setup for android studio
A Different Way :
It turns out there’s a better way to manage multiple projects in Android Studio. The trick is to create separate Android Studio projects for your libraries and to tell gradle that the module for the library that your app depends on is located in the library’s project directory. If you wanted to use this method with the project structure I’ve described above, you would do the following:
Create an Android Studio project for the StickyListHeaders library
Create an Android Studio project for App2
Create an Android Studio project for App1
Configure App1 and App2 to build the modules in the StickyListHeaders project.
The 4th step is the hard part, so that’s the only step that I’ll describe in detail. You can reference modules that are external to your project’s directory by adding a project statement in your settings.gradle file and by setting the projectDir property on the ProjectDescriptor object that’s returned by that project statement:
The code one has to put in settings.gradle:
include ':library1'
project(':library1').projectDir = new File('../StickyListHeader/library1')
If you’ve done this correctly, you’ll notice that the modules referenced by your project will show up in the project navigator, even if those modules are external to the project directory:
This allows you to work on library code and app code simultaneously. Version control integration also works just fine when you reference modules externally this way. You can commit and push your modifications to the library code just like you can commit and push modifications to your app code.
This way of setting up multiple projects avoids the difficulties that plague Google’s recommended configuration. Because we are referencing a module that is outside of the project directory we don’t have to make extra copies of the library module for every app that depends on it and we can version our libraries without any sort of git submodule nonsense.
Unfortunately, this other way of setting up multiple projects is very difficult to find. Obviously, its not something you’ll figure out from looking at Google’s guide, and at this point, there’s no way to configure your projects in this way by using the UI of Android Studio.

Check out this link about multi project setups.
Some things to point out, make sure you have your settings.gradle updated to reference both the app and library modules.
settings.gradle: include ':app', ':libraries:lib1', ':libraries:lib2'
Also make sure that the app's build.gradle has the followng:
dependencies {
compile project(':libraries:lib1')
}
You should have the following structure:
MyProject/
| settings.gradle
+ app/
| build.gradle
+ libraries/
+ lib1/
| build.gradle
+ lib2/
| build.gradle
The app's build.gradle should use the com.android.application plugin while any libraries' build.gradle should use the com.android.library plugin.
The Android Studio IDE should update if you're able to build from the command line with this setup.

For Intellij IDEA (and Android Studio) each library is a Module. Think of a Module in Android Studio as an equivalent to project in Eclipse. Project in Android Studio is a collection of modules. Modules can be runnable applications or library modules.
So, in order to add a new android library project to you need to create a module of type "Android library". Then add this library module to the dependency list of your main module (Application module).

The simplest way for me to create and reuse a library project:
On an opened project file > new > new module (and answer the UI questions)
check/or add if in the file settings.gradle: include ':myLibrary'
check/or add if in the file build.gradle:
dependencies {
...
compile project(':myLibrary')
}
To reuse this library module in another project, copy it's folder in the project instead of step 1 and do the steps 2 and 3.
You can also create a new studio application project
You can easily change an existing application module to a library module by changing the plugin assignment in the build.gradle file to com.android.library.
apply plugin: 'com.android.application'
android {...}
to
apply plugin: 'com.android.library'
android {...}
more here

You can add a new module to any application as Blundell says on his answer and then reference it from any other application.
If you want to move the module to any place on your computer just move the module folder (modules are completely independent), then you will have to reference the module.
To reference this module you should:
On build.gradle file of your app add:
dependencies {
...
compile project(':myandroidlib')
}
On settings.gradle file add the following:
include ':app', ':myandroidlib'
project(':myandroidlib').projectDir = new File(PATH_TO_YOUR_MODULE)

Don't forget to use apply plugin: 'com.android.library' in your build.gradle instead of apply plugin: 'com.android.application'

Documentation Way
This is the recommended way as per the advice given in the Android Studio documentation.
Create a library module
Create a new project to make your library in. Click File > New > New Module > Android Library > Next > (choose name) > Finish. Then add whatever classes and resourced you want to your library.
When you build the module an AAR file will be created. You can find it in project-name/module-name/build/outputs/aar/.
Add your library as a dependency
You can add your library as a dependency to another project like this:
Import your library AAR file with File > New Module > Import .JAR/.AAR Package > Next > (choose file location) > Finish. (Don't import the code, otherwise it will be editable in too many places.)
In the settings.gradle file, make sure your library name is there.
include ':app', ':my-library-module'
In the app's build.gradle file, add the compile line to the dependencies section:
dependencies {
compile project(":my-library-module")
}
You will be prompted to sync your project with gradle. Do it.
That's it. You should be able to use your library now.
Notes
If you want to make your library easily available to a larger audience, consider using JitPac or JCenter.

Had the same question and solved it the following way:
Start situation:
FrigoShare (root)
|-Modules: frigoshare, frigoShare-backend
Target: want to add a module named dataformats
Add a new module (e.g.: Java Library)
Make sure your settings.gradle look like this (normally automatically):
include ':frigoshare', ':frigoShare-backend', ':dataformats'
Make sure (manually) that the build.gradle files of the modules that need to use your library have the following dependency:
dependencies {
...
compile project(':dataformats')
}

Purpose: Android library at single place - Share across multiple projects
http://raevilman.blogspot.com/2016/02/android-library-project-using-android.html

As theczechsensation comment above I try to search about Gradle Build Varians and I found this link: http://code.tutsplus.com/tutorials/using-gradle-build-variants--cms-25005
This is a very simple solution. This is what I did:
- In build.gradle:
flavorDimensions "version"
productFlavors {
trial{
applicationId "org.de_studio.recentappswitcher.trial"
flavorDimension "version"
}
pro{
applicationId "org.de_studio.recentappswitcher.pro"
flavorDimension "version"
}
}
Then I have 2 more version of my app: pro and trial with 2 diffrent packageName which is 2 applicationId in above code so I can upload both to Google Play. I still just code in the "main" section and use the getpackageName to switch between to version. Just go to the link I gave for detail.

There are two simplest ways if one does not work please try the other one.
Add dependency of the library inside dependency inside build.gradle file of the library u r using, and paste ur library in External Libraries.
OR
Just Go to your libs folder inside app folder and paste all your .jar e.g Library files there Now the trick here is that now go inside settings.gradle file now add this line "include ':app:libs'" after "include ':app'" It will definitely work...........:)

In my case, using MAC OS X 10.11 and Android 2.0, and by doing exactly what Aqib Mumtaz has explained.
But, each time, I had this message : "A problem occurred configuring project ':app'. > Cannot evaluate module xxx : Configuration with name 'default' not found."
I found that the reason of this message is that Android 2.0 doesn't allow to create a library directly. So, I have decided first to create an app projet and then to modify the build.gradle in order to transform it as a library.
This solution doesn't work, because a Library project is very different than an app project.
So, I have resolved my problem like this :
First create an standard app (if needed) ;
Then choose 'File/Create Module'
Go to the finder and move the folder of the module freshly created in your framework directory
Then continue with the solution proposed by Aqib Mumtaz.
As a result, your library source will be shared without needing to duplicate source files each time (it was an heresy for me!)
Hoping that this help you.