I have built a dynamic library in android using android build system. This library provides jni interface for functions inside it. Now I want to include this library in an application (.apk). I am using eclipse for application development. Now, how can I use the prebuild dynamice library (.so) in my application ? I tried putting it in a lib folder in my application but it is not working.
Any pointers are appreciated.
I am not using ndk to build my .so.
Since you write 'so' I think you're using NDK. If you're using NDK I don't know the answer.
If you're using the "Java" SDK, then in your library project go to Properties -> Android, and Check "Is Library". In your "apk" project, go to Properties -> Android -> Add . And your Library project should be available.
Also, any Library added in the "Java Build Path" Menu (again, in project properties) should be available in the APK in the end.
I know it's slightly old, but have you checked in the built APK to see if your .so library is there? Should be in the libs/armeabi folder.
Also, your .so file should be in lib/armeabi folder in your eclipse solution. I'm guessing the armeabi bit depends on which processor your .so file is build for.
Also, I know that if your library isn't called lib[name].so, it won't get copied when the apk is installed on the device. So:
libfoo.so copies
foo.so doesn't copy
foo.so doesn't copy
Also, you can use DDMS (its a view in eclipse) and it's file explorer to see if it's been copied to your device. It should be under data/data/[packagename]/lib.
Hope this helps a bit!
Andy.
I hit this same problem while building Qiqqa for Android. Under your eclipse android project, make sure you have a libs directory (not that it is plural libS not singular lib). Inside that create the armeabi/etc subdirs with their respectibe .so files.
Then when you build, eclipse will automatically pick up this libs directory and create the corresponding lib in your apk. System.loadLibrary("XXX") will then resolve to libXXX.so on your correct architecture...
Cheers,
Jimme
Related
I'm building and Eclipse to make an Android library I want to distribute to developers.
TedLibJni:
It uses the Android NDK and so it compiles down to a .so file.
TedLibJar:
It also has a Java interface that binds the then extern'd calls in the JNI, so it has a Jar library associated with it.
TedDroidApp:
The concensus is that I need to manually copy both TedLibJni.so and TedLibJar.jar to lib/armeabi of this App for it to be used.
Question: Is there any way that TedDroidApp can pick up the externally located .so or .jar files? It seems crazy that I would have to manually copy and paste these files accross each time I iterate them.
Use an Android library project for the JNI code and the JAR. You can then attach the Android library project to other projects. With the new Gradle-based build system, you can package the library project up as an AAR and obtain it from an artifact repository as well.
CWAC-AndDown, my wrapper around the C hoedown library, works this way.
I've made an android library project that uses some native libraries.
I've made the jni wrapper and put the native libs (.so) in the libs// folders. The native libs are compiled using cmake, for armeabi, armeabi-v7a, x86 and mips.
I export this project to a jar and put this jar into a "normal" android project. I then export this project to an apk and can see that my libs are bundles into it.
However, when i install the apk, the libs corresponding to the device are not copied into /data/data/com.my.app/lib and obviously, running the app complains about not finding the libs (UnsatisfiedLinkError).
I've search through SO and everywhere i can but found no answer that solved my case.
i'm using Eclipse, btw
Thanks for your help
UPDATE
OK, i've read the doc in the ndk and seen the examples, and unfortunately, i can't see the solution.
The ndk build the c code into shared libs and places them into the appropriated location in the project. But it doesn't generate anything that says that the libs must be installed with the apk.
My goal is to provide an android library (so a jar), that can be included within an android application. I don't see the real difference between what i'm doing (compile the c libs using cmake and package the jni and java compiled classes into a jar) and what is done with android.mk
If you see what i'm missing, feel free to tell me (even if its obvious).
thanks
UPDATE
i've made a dirty hack: in the libs folder of my application, i've put the jar file containing my classes and my native libs and a copy of the .so files for each arch. Suprise, the libs are no installed in /data/data/com.me.myapp/lib
It seems to confirm that it's a packaging problem.
I export this project to a jar and put this jar into a "normal"
android project. I then export this project to an apk and can see that
my libs are bundles into it.
The issue is that the Android packaging system doesn't handle with binary assets in JARs. For your application project to find and include the generated .so files, you need it to reference the library project as an 'Android library project':
Did you call ndk-build command?
See description below for details.
http://developer.android.com/tools/sdk/ndk/index.html
You can build the shared libraries for the sample apps by going into /samples// then calling the ndk-build command. The generated shared libraries will be located under /samples//libs/armeabi/ for (ARMv5TE machine code) and/or /samples//libs/armeabi-v7a/ for (ARMv7 machine code).
As the topic indicates I would like to create a jar library that uses some android functions (no layouts) and that will be included in an Android project.
Is that possible and how?
From the research I've made I managed to include a simple jar file that uses pure Java (JAVA SE 1.6), but
when I tried creating a jar file I encountered the following exception when I tried to run the Andoid app: FATAL EXCEPTION: main
java.lang.NoClassDefFoundError: mylib.pleasework.amen
I tried including android.jar in my library and removing the java library, so that the jar file is build against android sdk, but it didn't work.
I tried including the jar file under a /libs folder as it is said to be the correct way to import jars in android projects from ADT v17 and after, but that didn't work either.
The jar I want to create will not use any resources (xml layouts, strings.xml) just Log.d and WifiManager.I am aware of Android Library Project but my library source is sensitive and I am afraid that it won't be safe if exposed in a Android library project. I was thinking of creating a jar and using ProGuard ( http://developer.android.com/tools/help/proguard.html ) obfuscate it.
I think I mentioned everything. Any help will be appreciated.
Thanks,
Thomas
As the topic indicates I would like to create a jar library that uses some android functions (no layouts) and that will be included in an Android project. Is that possible and how?
Use the jar command, or the <jar> Ant task. I am sure that there are ways to export a JAR from Eclipse, but I personally have never used them.
For example, in this GitHub repo I have a reusable component and a sub-project that is a sample app. My build.xml for the repo contains the following custom task:
<target name="jar" depends="debug">
<jar
destfile="bin/CWAC-WakefulIntentService.jar"
basedir="bin/classes"
/>
</target>
This generates a JAR file, that other Android applications can use by adding to their libs/ directories.
I am aware of Android Library Project but my library source is sensitive and I am afraid that it won't be safe if exposed in a Android library project.
It won't be safe exposed as a JAR, then, either. You can create an Android library project for public consumption that replaces the src/ tree's contents with a compiled JAR in libs/ in the library.
The way I did it in the end was: to create an Android Library project (check isLibrary checkbox in project properties) export it through Eclipse (right click on the project->export->jar file, careful to deselect all resources - res folder, androidmanifest.xml, *.png etc) and put it in the project you want by importing it under /libs folder. I don't know if this is the best solution but it worked for me.Used ADT r20, Eclipse 3.7.1, Android api level 7
I've built OpenSSL into an Android Library that I would like to reference from another Android project.
Unfortunately,
Yes, I do need OpenSSL, as I need to change the behaviour of dependant Android classes not in the public API. (not enough space here)
My experience with native code is non-existant.
The project is selected as a library in Preferences > Android
This library is referenced from a second Android project
My Questions are these
How can I reference the .so files in my Android library from Android.mk in my second project so that I can build dependant files there? I'd prefer not to put the .so files directly in my second project - but if that is the only solution I would accept reasons and directions as an answer.
How should I include/reference the .so file in files I am building in the second project?
Surely, it is something simple.
Thanks in advance.
once you generate (.so) library file, then make a folder in your applitcation's project folder named "libs/armeabi/" put (.so) file in this folder
and in your application write
System.loadLibrary("library_name");
I am creating a widget that we will provide to developer end users and it consists of a .jar and a native library (.so) built using the NDK. The JAR has a JNI interface to the dynamic library.
It's very clear on how to include an external .jar in a project but not how to include a dependent dynamic library.
How do I package up and build the .jar and .so? What are the best practices here?
I can create the JAR file using the JDK's jar command. Do I need to run dx.bat on the jar to convert to Dalvik bytecode?
I need to create a sample project showing the widget in action. How do I include this .jar and .so in a sample project that demonstrates how to use the widget?
I spent some time on this, and i just can't understand why isn't this written on wikitude documentation.... anyway follow this changes!
go to windows/preferences/android/build
uncheck the first and the second option
extract files from wikitudesdk.jar with winrar as if it is an archive, search libarchitect.so and copy it in /libs/libs/armeabi/
add wikitudesdk.jar to your build path
You should use the standard build tools included with the SDK for this. If you include the .jar files you need in the /lib directory of your project, the ant build process will convert the included class files to Dalvik bytecode format and include them in your classes.dex file for the app. Add a build.properties file to your project root as well, with one line:
external.libs.dir=lib
Depending on the version of your SDK and configuration of it, you may need to place the jar in libs rather than lib.
As for the .so, I presume that it's properly compiled using the Android NDK, or using a build script that uses the proper compiler and compiler flags that are required to successfully link the shared object on Android. If this is the case, you can include the .so file in libs/armeabi and they will be added in the jar as well. Furthermore, the dynamic library loader will know to look in this location in the .jar when you actually try to load the library from Java code.
Using ADT 12, I accomplished this by doing the following:
1) Export JAR from your library with the SO file using Eclipse. Make sure you exclude AndroidManifest.xml. This will include source code and other data, so if you are distributing, you'll want to strip these unnecessary bits out using any ZIP utility.
2) Create a directory in your App's source tree (I use "lib" directory) and copy your library JAR to it.
3) Right-click project in Eclipse and select "Configure Build Path". Add JAR and point it to JAR inside your App source tree.
4) In your Eclipse preferences, select Android/Build section and uncheck "Automatically refresh Resources and Assets folder on build". You will notice an option below that says "Force error when external jars contain native libraries." There is an ADT bug, which will supposedly be fixed in R17, which uses the wrong setting. Once it is fixed, you will use the "Force error" one (make sure it unchecked).
5) Once you build your app APK, you will have a libs/armeabi/libXXXX.so file. This will not be automatically unpacked on install. You will need to write code to extract it from your APK file into your data directory, then use System.load on the .so file in your data directory.
I have bidirectional JNI calls going from the dynamically loaded file, and even use dlopen() on it to do my custom plugin registration stuff.
Add the below lines to android.mk.
include $(BUILD_PACKAGE)
LOCAL_PREBUILT_STATIC_JAVA_LIBRARIES := alias:libs/your.jar
include $(BUILD_MULTI_PREBUILT)