How to import external jar file into Firefox fennec moz.build file? -

i'm building customized version of firefox fennec, , added ui uses android's recyclerview. want import android-support-v7-recyclerview.jar moz.build file don't know how.

i have tried add android-support-v7-recyclerview.jar gbjar.extra_jars, gives me exceptions below.

exception in thread "main" java.lang.noclassdeffounderror: android/support/v7/widget/recyclerview$layoutmanager  0:46.88    @ java.lang.class.getdeclaredmethods0(native method)  0:46.88    @ java.lang.class.privategetdeclaredmethods(class.java:2615)  0:46.88    @ java.lang.class.getdeclaredmethods(class.java:1860)  0:46.88    @ org.mozilla.gecko.annotationprocessors.utils.generatableelementiterator.<init>(generatableelementiterator.java:32)  0:46.88    @ org.mozilla.gecko.annotationprocessors.annotationprocessor.main(annotationprocessor.java:74)  0:46.88 caused by: java.lang.classnotfoundexception: android.support.v7.widget.recyclerview$layoutmanager  0:46.88    @ java.net.urlclassloader$1.run(urlclassloader.java:366)  0:46.88    @ java.net.urlclassloader$1.run(urlclassloader.java:355)  0:46.88    @ java.security.accesscontroller.doprivileged(native method)  0:46.88    @ java.net.urlclassloader.findclass(urlclassloader.java:354)  0:46.88    @ java.lang.classloader.loadclass(classloader.java:425)  0:46.88    @ java.lang.classloader.loadclass(classloader.java:358)  0:46.88    ... 5 more 

is there more in moz.build?

there makefile.in file in /mozilla-central/mobile/android/base/ find all_jars , add external jar file there!