Issue 1848 - Clean up local reference handling

jni/JniEventCallback.cpp

Index: jni/JniEventCallback.cpp
diff --git a/jni/JniEventCallback.cpp b/jni/JniEventCallback.cpp
index c92a48845b979d9ae45a52bfaa33e0e9494625de..e2035d9d83f9f0a1e5d6eaad8187763621c31cde 100644
--- a/jni/JniEventCallback.cpp
+++ b/jni/JniEventCallback.cpp
@@ -40,8 +40,10 @@ void JniEventCallback::Callback(AdblockPlus::JsValueList& params)
 {
   JNIEnvAcquire env(GetJavaVM());
 
-  jclass clazz = env->GetObjectClass(GetCallbackObject());
-  jmethodID method = env->GetMethodID(clazz, "eventCallback", "(Ljava/util/List;)V");
+  jmethodID method = env->GetMethodID(
+      *JniLocalReference<jclass>(*env,

[Felix Dahlke, 2015/02/03 05:22:50]

I think I've seen at least three instances of pretty much this code - have you
thought about returning a JniLocalReference<jclass> from something like
JniCallbackBase::GetCallbackClass()?

[René Jeschke, 2015/02/03 13:51:26]

Yeah, the first implementation supported this, but not this here because I do
not have a copy constructor. Implementing a copy constructor would also mean
implementing reference counting, which I thought of as a little bit of
over-engineering.

So, we should leave it like it is.

[Felix Dahlke, 2015/02/04 04:11:50]

Good point, yeah.

+          env->GetObjectClass(GetCallbackObject())),
+      "eventCallback", "(Ljava/util/List;)V");
 
   if (method)
   {