Adding a Third Party Library to the Android Host

[sgeos]

I have managed to add Lua-SQLite3 to the OSX and iOS hosts, but extending the Android host is not as straightforward as I had anticipated. I am building libluasqlite3.o without any problems, but nm indicates that it does not have any symbols. I am not sure if the problem is the object file or nm. I get a java.lang.UnsatisfiedLinkError when I try to run my APK on the simulator.

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1. $ ./run-host.sh


2. # snip initialization


3. E/AndroidRuntime(  986): FATAL EXCEPTION: main


4. E/AndroidRuntime(  986): java.lang.UnsatisfiedLinkError: AKUExtLoadLuasqlite3


5. E/AndroidRuntime(  986):        at com.ziplinegames.moai.Moai.AKUExtLoadLuasqlite3(Native Method)


6. E/AndroidRuntime(  986):        at com.ziplinegames.moai.Moai.init(Moai.java:283)


7. E/AndroidRuntime(  986):        at com.sennue.test.MoaiActivity.onCreate(MoaiActivity.java:70)


8. E/AndroidRuntime(  986):        at android.app.Activity.performCreate(Activity.java:4465)


9. E/AndroidRuntime(  986):        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)


10. E/AndroidRuntime(  986):        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)


11. E/AndroidRuntime(  986):        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)


12. E/AndroidRuntime(  986):        at android.app.ActivityThread.access$600(ActivityThread.java:123)


13. E/AndroidRuntime(  986):        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)


14. E/AndroidRuntime(  986):        at android.os.Handler.dispatchMessage(Handler.java:99)


15. E/AndroidRuntime(  986):        at android.os.Looper.loop(Looper.java:137)


16. E/AndroidRuntime(  986):        at android.app.ActivityThread.main(ActivityThread.java:4424)


17. E/AndroidRuntime(  986):        at java.lang.reflect.Method.invokeNative(Native Method)


18. E/AndroidRuntime(  986):        at java.lang.reflect.Method.invoke(Method.java:511)


19. E/AndroidRuntime(  986):        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)


20. E/AndroidRuntime(  986):        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)


21. E/AndroidRuntime(  986):        at dalvik.system.NativeStart.main(Native Method)


22. ^C


23. $

I think this is a JNI problem. I found a few threads on the net that cover the JNI (link 1, link 2, link 3), but it is not immediately obvious how I need to apply this information to enhance the Android host. What do I need to do to add a third party library to the Android host?

[ibisum]

You need to add the JNI side of AKUExtLoadLuasqlite3 .. in a .java file, added to the MOAI host build project. That .java file has to follow the naming conventions used throughout the library interfaces - best would be to have a look at an existing working example from the 3rdparty tree, and see how its mapped. You have to finish the JNI work, it seems.

[sgeos]

Where is the JNI side of AKUExtLoadLuacrypto() defined? It did not appear to be in the 3rdparty tree, nor did it appear to be in src/aku or the Android host. The function is declared in src/aku/AKU-luaext.cpp. I'm sure I've missed something simple and I will keep looking.

[ibisum]

I'm actually finding it in the Android host template code, which is used by make-host.sh to produce android-host/ (or 'unknown-host' as its called) according to configuration - so some code does not get included if its not configured for inclusion.

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1.  


2. w1x@w1x0-dev:~/moai-dev-1.2/ant$ grep -ir AKUExtLoadLuacrypto *


3. host-source/source/project/src/moai/Moai.java:  protected static native void    AKUExtLoadLuacrypto                     ();


4. host-source/source/project/src/moai/Moai.java:                  AKUExtLoadLuacrypto ();


5. libmoai/jni/src/moai.cpp:       extern "C" void Java_com_ziplinegames_moai_Moai_AKUExtLoadLuacrypto ( JNIEnv* env, jclass obj ) {


6. libmoai/jni/src/moai.cpp:               AKUExtLoadLuacrypto ();


7.  

By the way: maybe thats a missing step for you, and my rule/advice when working on extending the Android host: ALWAYS modify the Android template code, then re-make the Android project, to test your Android/JNI work. You can re-build the JNI libs and copy them into a 'test Android project' while you do development, but don't forget to re-generate a brand new Android project from scratch, to make sure you haven't broken the make-host.sh script with a change.

Its maybe a little hassle, but remember that there is the host-making phase in the build of the SDK, and if you don't "test through that" you can run into troubles [like, overwriting your valuable code next time you use make-host.sh, if you haven't been already using it..]

(PS- I'm working from repo (never the SDK) ..)

[sgeos]

Thanks. I managed to sort out the initialization problem. FWIW, the following is my new friend:

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1. grep -r1 'whatever_I_am_looking_for' ./dir_it_ought_to_be_in

[stanziano]

I'm trying to add LuaSQLite3 to an Android host...I followed your instructions and checked the work made by sgeos in its fork ( https://github.com/sgeos/moai-dev/tree/master/ant ).
I built the host and compiled an example using sqlite3 ( https://github.com/Sennue/rainbow-bubbles from sgeos repositories)..no problems till here.
When I run the app on the device this error message occurs:

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1. 05-08 18:09:54.831 25712 25712 I MoaiLog : MoaiRenderer runScripts: Running main                                                                                                    .lua script


2. 05-08 18:09:54.841 25712 25712 I MoaiLog : Database.lua:22: module 'sqlite3' not                                                                                                     found:


3. 05-08 18:09:54.841 25712 25712 I MoaiLog :      no field package.preload['sqlite                                                                                                    3']


4. 05-08 18:09:54.841 25712 25712 I MoaiLog :      no file 'sqlite3'


5. 05-08 18:09:54.841 25712 25712 I MoaiLog :      no file 'sqlite3.lua'


6. 05-08 18:09:54.841 25712 25712 I MoaiLog :      no file './lua-modules/moai/sqli                                                                                                    te3.lua'


7. 05-08 18:09:54.841 25712 25712 I MoaiLog :      no file './sqlite3.so'


8. 05-08 18:09:54.841 25712 25712 I MoaiLog :      no file '/usr/local/lib/lua/5.1/                                                                                                    sqlite3.so'


9. 05-08 18:09:54.841 25712 25712 I MoaiLog :      no file '/usr/local/lib/lua/5.1/                                                                                                    loadall.so'


10. 05-08 18:09:54.841 25712 25712 I MoaiLog : stack traceback:


11. 05-08 18:09:54.841 25712 25712 I MoaiLog :      [C] ?


12. 05-08 18:09:54.841 25712 25712 I MoaiLog :      [C] in function 'require'


13. 05-08 18:09:54.841 25712 25712 I MoaiLog :      Database.lua:22 in main chunk


14. 05-08 18:09:54.841 25712 25712 I MoaiLog :      [C] in function 'require'

Thus I tried to copy sqlite3.lua, sqlite3.so and libluasqlite3-loader.lua in the source folder of the app but now the error is:

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1.  


2. 05-08 18:25:26.386 28424 28424 I MoaiLog : MoaiRenderer runScripts: Running main.lua script


3. 05-08 18:25:26.396 28424 28424 I MoaiLog : libluasqlite3-loader.lua:47: dynamic libraries not enabled; check your Lua installation


4. 05-08 18:25:26.396 28424 28424 I MoaiLog : stack traceback:


5. 05-08 18:25:26.396 28424 28424 I MoaiLog :      [C] ?


6. 05-08 18:25:26.396 28424 28424 I MoaiLog :      [C] in function 'assert'


7. 05-08 18:25:26.396 28424 28424 I MoaiLog :      libluasqlite3-loader.lua:47 in function 'load_libluasqlite3'


8. 05-08 18:25:26.396 28424 28424 I MoaiLog :      sqlite3.lua:49 in main chunk


9. 05-08 18:25:26.396 28424 28424 I MoaiLog :      [C] in function 'require'


10. 05-08 18:25:26.396 28424 28424 I MoaiLog :      Database.lua:22 in main chunk


11. 05-08 18:25:26.396 28424 28424 I MoaiLog :      [C] in function 'require'


12. 05-08 18:25:26.396 28424 28424 I MoaiLog :      ProgramState.lua:21 in main chunk


13. 05-08 18:25:26.396 28424 28424 I MoaiLog :      [C] in function 'require'


14. 05-08 18:25:26.396 28424 28424 I MoaiLog :      main.lua:20 in main chunk


15.  


16.  

Does anybody have a suggestion?

[stanziano]

Problem fixed: the error was using the wrong library and loader files.
The correct ones are here:
https://github.com/sgeos/moai-dev/blob/ ... loader.lua
https://github.com/sgeos/moai-dev/blob/ ... qlite3.lua

Always by sgeos...Thank you very much sgeos!!

It would be really nice to include these changes in the official version and provide a brief documentation!

LuaSQLite3 API support is a MUST in my opinion!