Javah Error android.app.Activity not found

android android-ndk java-native-interface javah
Ayesh Qumhieh picture Ayesh Qumhieh · May 7, 2012 · Viewed 14.1k times · Source

I'm trying to create a .h header file for a simple NDK project. Using cygwin I browse to myprojectDIR\jni directory, then execute this command:

javah -o com_myproject_MyActivity.h -classpath  myprojectDIR\bin\classes com.myproject.MyActivity

then this error message appears:

Error: cannot access android.app.Activity
class file for android.app.Activity not found

I have a native method inside MyActivity class, so I tried to create a new class called NativeAccess (does not extend any class from the android SDK) and it worked fine, the .h file was created, ndk-build and test on device where successful!

So my problem is that I need my native methods inside android activities and services that I create, but I cant do that because the Javah command cannot access classes from inside the android-sdk itself. Please notice that I'm using (Windows-7 x64) and I have these environment variables:

ANDROID_NDK : C:\Android\android-ndk-r7b
ANDROID_SDK : C:\Android\android-sdk
ANT_HOME    : C:\ANT\apache-ant-1.8.3
JAVA_HOME   : C:\Program Files\Java\jdk1.7.0_02
PATH        : %JAVA_HOME%\bin;%ANDROID_SDK%\tools;%ANDROID_SDK%\platform-tools;%ANDROID_NDK%;%ANT_HOME%\bin; (other unrelated stuff)

Thanks in advance

Answer

JonnyBoy picture JonnyBoy · May 14, 2012

Try adding to your classpath:

-classpath <android-sdk-location>/platforms/android-8.jar

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