Problem using context and JNI

[Damalo_02]

Hello,

I would like to do an Android app using FTDI Java library and Qt.
Firstly, because I found easier to code in Java, I did my app on Android Studio and it works well.
FTDI methods use application context as argument :

Now I'm trying to do the same app on Qt Creator.
As a simple example, I'm just trying to call a Java method (that uses application context) from C++ using JNI.

The problem is I'm getting this error and I don't know how to solve it :

W/System.err(15479): java.lang.NoSuchMethodError: no static method "Lcom/ftdi/d2xxjava/MyApplication;.testStatic(I, Landroid/content/Context)V"
W/System.err(15479): at org.qtproject.qt5.android.QtNative.startQtApplication(Native Method)
W/System.err(15479): at org.qtproject.qt5.android.QtNative$6.run(QtNative.java:365)
W/System.err(15479): at org.qtproject.qt5.android.QtThread$1.run(QtThread.java:61)
W/System.err(15479): at java.lang.Thread.run(Thread.java:818)

Here is my Java code :

C++ call :

"MyApplication" Class doesn't extend QtActivity, can it be the problem?
If I do so, I get an other error :

F/art (17395): sart/runtime/check_jni.cc:65] JNI DETECTED ERROR IN APPLICATION: JNI GetMethodID called with pending exception 'java.lang.RuntimeException' thrown in unknown throw location
F/art (17395): sart/runtime/check_jni.cc:65] in call to GetMethodID
F/art (17395): sart/runtime/check_jni.cc:65] from void org.qtproject.qt5.android.QtNative.startQtApplication()
F/art (17395): sart/runtime/check_jni.cc:65] "qtMainLoopThread" prio=5 tid=5 Runnable
F/art (17395): sart/runtime/check_jni.cc:65] | group="main" sCount=0 dsCount=0 obj=0x12c231c0 self=0xab350fb8
F/art (17395): sart/runtime/check_jni.cc:65] | sysTid=17471 nice=0 cgrp=default sched=0/0 handle=0xab2dafd0
F/art (17395): sart/runtime/check_jni.cc:65] | state=R schedstat=( 230849873 94922049 241 ) utm=23 stm=0 core=1 HZ=100
F/art (17395): sart/runtime/check_jni.cc:65] | stack=0x4c11e000-0x4c120000 stackSize=1036KB
F/art (17395): sart/runtime/check_jni.cc:65] | held mutexes= "mutator lock"(shared held)
F/art (17395): sart/runtime/check_jni.cc:65] native: #00 pc 00004e84 /system/lib/libbacktrace_libc++.so (_ZN13UnwindCurrent6UnwindEjP8ucontext+23)
F/art (17395): sart/runtime/check_jni.cc:65] native: #01 pc 0000369d /system/lib/libbacktrace_libc++.so (_ZN9Backtrace6UnwindEjP8ucontext+8)

Thanks

[raven-worx]

@Damalo_02 said in Problem using context and JNI:

(I, Landroid/content/Context)V

is not a correct JNI signature.
Correct: (ILandroid/content/Context)V

[KroMignon]

@raven-worx said in Problem using context and JNI:

Correct: (ILandroid/content/Context)V

I think you missed a semicolone symbole and it should be (ILandroid/content/Context;)V

=> cf. JNI Types and Data Structures

Regards

Fabrice

[Damalo_02]

Yes it was a problem of JNI signature, and you're right @KroMignon a semicolon is missing.

Right signature is : (ILandroid/content/Context;)V

Thanks a lot for your help