下面是我的python代码，它成功地工作到了一定程度：

from jnius import autoclass, PythonJavaClass, java_method, cast
from kivy.app import App
import logging

testmode = True

PythonActivity = autoclass("org.kivy.android.PythonActivity")
Unity_ads_listener = autoclass("com.unity3d.ads.IUnityAdsListener")
Unity_ads = autoclass("com.unity3d.ads.UnityAds")

 class Unity_handler:

   def __init__(self, a_id):
     self.app_id = a_id

   def init_unity(self):

     new_ad_listener = UnityAdsListener()
     Unity_ads.addListener(new_ad_listener)
     self.c_activity = cast('android.app.Activity',PythonActivity.mActivity)
     Unity_ads.initialize(self.c_activity,self.app_id,testmode)
     logging.warning("\n Unity ads initialized \n")

   def show_ad(self, id_num):

     #show interstial ads
     self.inter_id = id_num
     if Unity_ads.isReady(self.inter_id):
          try:
            Unity_ads.show(self.c_activity, self.inter_id)
          except:
            fail=1 

 class UnityAdsListener(PythonJavaClass):
    __javacontext__= 'app'
    __javainterfaces__= ['com/unity3d/ads/IUnityAdsListener']  

    #def __init__(self):
    #            super(IUnityAdsListener, self).__init__()
    #            #self.callback = callback

    @java_method('(Ljava/lang/String;)V')
    def onUnityAdsReady(inter_id):
       pass        

    @java_method('(Ljava/lang/String;)V')   
    def onUnityAdsStart(inter_id):
       pass

    @java_method('(Ljava/lang/String;Ljava/lang/String;)V')
    def onUnityAdsFinish(inter_id,un_f):
       pass

    @java_method('(Lcom/unity3d/ads/UnityAds$UnityAdsError;Ljava/lang/String;)V')
    def onUnityAdsError(self,error, message):
       pass

我展示了这些广告，但经过一段时间的反复展示，很快就崩溃了。我怀疑从java接口继承的java方法可能有问题。这是一份坠机报告：
09-05 16:51:40.775 260 454 d audioflinger \u threads:0xa8603180:threadloop \u write write muted data to hw，mixerstatus 1 start 09-05 16:51:40.778 12274 12274 i python:traceback（最近一次调用）：09-05 16:51:40.780 789 840 v windowmanager:looking for focus:8=window{deb1e08 u0 statusbar}，flags=-2122055608，canreceive=false 09-05 16:51:40.780 12274 12274 i python:文件“jnius/jnius\u proxy.pxi”，第156行，在jnius.jnius.invoke0 09-05 16:51:40.781 789 840 d windowmanager:notifyactivitydrawnforkeyguard:waiting=false callers=com.android.server.wm.windowsurfaceplacer.handlapptransitionre中adylocked:1227 com.android.server.wm.windowsurfaceplacer.performsurfaceplacementinner：337 com.android.server.wm.windowsurfaceplacer.performsurfaceplacementloop:235 com.android.server.wm.windowsurfaceplacer.performsurfaceplacement:183 com.android.server.wm.windowmanagerservice$h.手lemessage:8417 09-05 16:51:40.781 12274 12274 i python:文件“jnius/jnius\u proxy.pxi”，第124行，在jnius.jnius.py\u invoke0 09-05 16:51:40.781 789 840 v windowmanager:查找焦点：8=window{deb1e08 u0 statusbar}，标志=-2122055608，canreceive=false 09-05 16:51:40.782 12274 12274 i python:attributeerror:'kivy.core.text.text\u layout.layoutword'对象没有属性'invoke'09-05 16:51:40.783 12274 12274 d androidruntime:关闭vm 09-05 16:51:40.786 789 840 i活动管理器：显示com.oracle.oracle/com.unity3d.services.ads.adunit活动：+166ms 09-0516:51:40.787 789 882 i libperfservice:1:set:3 09-05 16:51:40.787 789 882 i libperfservice:1:set freq:819000 09-05 16:51:40.792 12274 12274 e androidruntime:致命异常：main 09-05 16:51:40.792 12274 12274 e androidruntime:进程：com.oracle.oracle，pid:12274 09-05 16:51:40.792 12274 12274 e androidruntime:java.lang.nullpointerexception:应取消“int”基元类型的装箱，但返回null 09-05 16:51:40.792 12274 12274 e androidruntime:at$proxy0。哈希代码（未知源）09-05 16:51:40.792 12274 12274 e androidruntime:atsun.misc.hashing.singlewordwangjenkinshash（哈希）。java:48)09-05 16:51:40.792 12274 12274 e androidruntime:在java.util.hashmap.put（hashmap。java:423)09-05 16:51:40.792 12274 12274 e androidruntime:位于java.util.hashset.add（hashset。java:217)09-05 16:51:40.792 12274 12274东安德罗尼时间：atjava.util.abstractcollection.addall（抽象集合。java:342)09-05 16:51:40.792 12274 12274 e androidruntime:位于java.util.linkedhashset.（linkedhashset。java:169)09-05 16:51:40.792 12274 12274 e androidruntime:网址：com.unity3d.ads.properties.adsproperties.getlisteners（adsproperties）。java:47)09-05 16:51:40.792 12274 12274东安德罗尼时间：atcom.unity3d.services.ads.api.listener$5.run（listener。java:76)09-05 16:51:40.792 12274 12274 e androidruntime:在android.os.handler.handlecallback（handler。java:836)09-05 16:51:40.792 12274 12274 e androidruntime:在android.os.handler.dispatchmessage（handler。java:103)09-05 16:51:40.792 12274 12274东安德罗尼时间：atandroid.os.looper.loop（looper。java:203)09-05 16:51:40.792 12274 12274 e androidruntime:at android.app.activitythread.main（活动线程）。java:6251)09-05 16:51:40.792 12274 12274 e androidruntime:at java.lang.reflect.method.invoke（本机方法）09-05 16:51:40.792 12274 12274 e androidruntime:atcom.android.internal.os.zygoteinit$methodandargscaller.run（zygoteinit。java:1063)09-05 16:51:40.792 12274 12274 e androidruntime:网址：com.android.internal.os.zygoteinit.main（zygoteinit。java:924)09-05 16:51:40.796 789 976 w活动管理器：force finishing activity com.oracle.oracle/com.unity3d.services.adunit.adunitivity