how to use android libraries in java project - java

I want to include android libraries in my java project. Actually, I need to run android code in java environment , obviously, this android code would not contain any GUI based action, it will simply use android's predefined libraries ... please suggest to me how android's libraries can be included in java project.
Thanks in Advance !

Find the JAR file containing the libraries you want to use, and add them to the Java project's build classpath.
However this may not work, depending on the Android classes you want to use. Some Android classes will have dependencies on the Android platform which will make it unlikely they will work ... or even load ... on a regular Java platform.

If you want to reference a java jar as reference:
Add that to libs folder in you project
Right click on project -> Properties - > java Build path -> libraries -> add jars
If you want reference a android library project then
Right click on project -> Properties - > Android - > Add (in lower part of window)
You can use android apis in android library project
Setting up library project refer.
You can find the difference between jar library and android library here

Related

How to create a standalone library in Android using AndroidStudio?

I am very new to JAVA/ Android world. I come from C background. The AndroidStudio / Gradle stuff is a bit overwhelming for me.
I am looking to create a library using AndroidStudio. But when I click on "Start a new Android Studio Project" it asks me for Application name and then for activity et al. This is where it gets confusing for me. Why would these details be required to create a library module? Am I missing something here?
I know that there is a File - > New Module Menu and all that stuff, but that comes later once I have set the applicaton details. But here, I dont want to create any application, just the lib (similar to a shared library I would create in C using Makefiles/autotools).
Also, A library in Android world is basically a jar file (like we have *.so in C), right?
1) While Android tools does accept/use Java JAR files, JARs don't contain Android specific stuff like resources (bitmaps,xml) as well as the necessary meta-data to properly merge all of that into a client project. So with the 'new' Gradle based tools we now have AAR format http://tools.android.com/tech-docs/new-build-system/aar-format and the toolchain knows how to handle them.
2) Which brings you to Create aar file in Android Studio

android-support-v7-appcompat library project won't work

I am trying to add Support Library v7 to my clean android project as support library (with resources). I followed every instruction here: http://developer.android.com/tools/support-library/setup.html#download and android.support.v7.* package is not visible in my main project.
Here is library reference in main project:
Support library project tree:
Support library project build path:
And finally, my main project tree
I don't see any errors in Problems tab, app compiles and runs normally but i cannot import android.support.v7 package which apparently isn't in build path in main project. I went through instruction twice in clean projects/workspace. I cleaned project, restarted Eclipse and nothing... All resources from library project are unreachable too.
Thanks in advance :)
Copy the library project to the folder where your android project is.
Select File > Import.
Select Existing Android Code Into Workspace and click Next.
Browse and import the same to eclipse
Once the library project is imported you can refer the same in your android project.
This is similar to setting up google play services in eclipse described here. Check the 4th step
http://developer.android.com/google/play-services/setup.html
It looks like android-support-v7-appcompat.jar is missing from your libs folder.
When you download the Android Support Library through the Android SDK Manager it makes the support .jar files you need available under {SDK Location}\extra\android\support.
To use the v7 files, copy these to your project's /libs folder.
android-support-v4.jar
android-support-v7-appcompat.jar
android-support-v7-gridlayout.jar (*if needed)
android-support-v7-mediarouter.jar (*if needed)
Typical gotchas (this looks OK in your setup):
Make sure the min SDK is at least API 7
Make sure the project target build is at least API 17
For more information about using the support V7 package (including running the v7 samples) can be found at the RHM Guide to Android Support Lib.
The issue seems to be in Absolute path in case of Windows base machine. I faced the issue of referencing support libraries When I moved Eclipse and related libraries to different drive than where the project was.
Copy paste the libraries to folder on same derive in a way that it can pick by relative path.
..\androidCommonlib\appcompat
android.library

Using Android Library on a Regular Java Project

I am looking to use an android class on a regular non-android java project. Specifically I want to use FaceDetector from android.media
I know that there are OpenCV and other libraries I can use to detect a face in an image but I am looking to use androids library. Is there a way to link androids library to a java project?
Thanks
Go to build path of your java project
Add a new external jar
Browse to the location of your android platform installation
(usually C:\Program Files (x86)\Android)
Under android-sdk\platforms\android-x (where x is the version of android you have) select the android.jar file to add to the project.
Now you have the android library under the referenced libraries, and you can use whatever android classes you want in your java project.
Another way of doing that is to use the android source, get only the java files you need from the android library and put them into your java project. The good thing when you do it this way is that you can modify the code and make it more compatible with your java work.
The android library might contain some calls to the system API's. Look for them before including the library with the above mentioned steps. I would recommend you to look into the documentation of the android library and look for the hooks where it calls android system APIs.Modify the source to use your webcam's API and then include it as a library

How to include a Java project in an Android project?

I am using Eclipse to develop an Android board game.
I have developed the UI in an Android project.
On the other hand, I have developed the AI in a regular Java project, because I wanted to be able to test it without all the constraints of the Android emulator (I didn't find any other way to run the code using my Windows JVM).
Now comes the times when I want to 'join' both projects (which work fine independently), that is to use the AI Java classes from the UI.
This is what I have tried:
In my Android project Properties > Projects References, I ticked the Java project.
This allows me to build without error the Android project (which instantiates an AI object).
But it fails at runtime with this error:
Could not find class 'my.package.AI', referenced from method my.otherpackage.UI.onStart
What would be the correct way to include the AI Java Project into my Android Project ?
(NB: I still want to be able to develop and test the AI as a regular Java app, so I think using a jar or copying all the sources to the Android Project would not suit my needs)
EDIT:
I was hoping that the new ADT v17 would solve the problem, but it didn't. I have tried virtually every option available to include a project in my Android project:
Adding or linking a source folder
Adding a Project (Java Build Path > Projects tab)
Adding a Class Folder or a Library (Java Build Path > Library tab)
Ticking all the previously imported projets/libraries as Exported
The only way that allows compiling and running without error is adding the JAR of the Java Project to the Android project build path.
Projects References only add the dependent project source code (your AI project) as a soft (perhaps weak is a more accurate word) reference, your AI project is not added into you Android Project Build path. so the actual ai.jar is not exported into the final apk when Eclipse build your app.
You should add AI project into Android project build path:
Right-click on your android project, select Build Path - Configure Build Path, in Projects tab (Required projects on the build path), add your AI project here.
Then in Order and Export tab (Build class path order and exported entries), tick your newly added AI project appeared int the list.
Step 2 is probably optional, this should add AI project as a reference in Android project and export the ai.jar to final.apk when Eclipse build your Android project.
Update from ADT 17.0.0:
Android Dev Team just release SDK r17 with ADT 17.0.0, which claims to handle this use cases properly now:
Eclipse specific changes
The dynamic classpath container called “Library Projects” has been renamed to “Android Dependencies” as it now contains more than just Library Projects.
The container will now also be populated with Java-only projects that are referenced by Library Projects. If those Java projects also reference other Java projects and/or jar files they will be added automatically (jar files referenced through user libraries are supported as well).
Important: this only happens if the references are set to be exported in the referencing project. Note that this is not the default when adding a project or jar file to a project build path.
Library Projects (and the content of their libs/*.jar files) is always exported. This change only impacts Java-only projects and their own jar files.
Again, duplicates (both projects and jar files) are detected and removed.
More in this link.
Edit: After much testing, reading and found my solution. Problem is (as of this writing) that you can't reference another project from an Android project, although it works fine for a normal Java application project.
Workaround for me (Windows with NTFS filesystem):
In a prompt (admin rights) make a symbolic folder link using mklink /D command pointing to your source project folders, and refresh in Eclipse as needed.
The obvious limitation is you cant use the same package names in source project and target project, and then there is the problem with libs in the common project.
example:
cd \java\workspace\AndroidProject\src\your\package
mklink /D common c:\java\workspace\CommonProject\src\your\package\common
Clarification: You can reference another project from an Android project to make it compile, however when you run, the referenced classes from the included project are not put in the apk classes.dex (verified with dex decompiler).
Using ADT 21.0.0 64bit on Windows 7 64bit. I tried adding project to build path. Ticked in the Order and Export, played with order. I read the official solution, the detailed explanation of that solution, exported as JAR, added to libs. Did not work, while the source was without errors. Read in the comments that the solution didn't work for everyone.
Was fed up with it and tried a simple but somewhat messier solution: linked the Java project's source to the Android project. That did the trick. Hope that this will help others too.
Don't add it to the project references area, instead go into the Android pane (in the Project Properties), scroll down to the bottom, and add it under Libraries.
This sometimes works but sometimes produces bizarre Eclipse issues (not sure why), in which case copying the jar directly into the project seems to work best.

Adding Non-Android Project to an Android Project

I have three projects in Eclipse: Base, Server, and AndroidClient. The Base and Server are Java 1.7 projects, while the AndroidClient is obviously an android project. The base project has classes and files that are shared between the server and android client.
I understand that the Android doesn't use all of the normal Java classes and there's some deal about the Dalvik being different enough from the JVM that you have to compile them separately. Assuming I'm careful not to use any java classes that android doesn't support in the base project, is there any way to include the base project as a library to the android client in a simple way?
Figured it out. The answer is to open up your Android projects Properties, Build Path, and click "Link Source...". Add the source directory for your base project. Now, your android project will build those files for the android as well.

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