Jumblr on Google App Engine - java.lang.SecurityException

[anuragkapur]

Jumblr does not work in an app deployed on Google App Engine, owing to Gson and the way it uses/depends on Reflection.

Below is a stack trace detailing the problem:
java.lang.SecurityException: java.lang.IllegalAccessException: Reflection is not allowed on private java.lang.String java.io.File.path
at com.google.appengine.runtime.Request.process-bc4f433d60aeb55d(Request.java)
at java.lang.reflect.Field.setAccessible(Field.java:166)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:116)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:72)
at com.google.gson.Gson.getAdapter(Gson.java:353)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.(ReflectiveTypeAdapterFactory.java:82)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:81)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:118)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:72)
at com.google.gson.Gson.getAdapter(Gson.java:353)
at com.google.gson.Gson.fromJson(Gson.java:794)
at com.google.gson.Gson.fromJson(Gson.java:859)
at com.google.gson.Gson$2.deserialize(Gson.java:131)
at com.tumblr.jumblr.responses.PostDeserializer.deserialize(PostDeserializer.java:22)
at com.google.gson.TreeTypeAdapter.read(TreeTypeAdapter.java:58)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:40)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:81)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:60)
at com.google.gson.Gson.fromJson(Gson.java:795)
at com.google.gson.Gson.fromJson(Gson.java:859)
at com.tumblr.jumblr.responses.ResponseWrapper.getPosts(ResponseWrapper.java:45)
at com.tumblr.jumblr.JumblrClient.blogPosts(JumblrClient.java:169)
at com.tumblr.jumblr.JumblrClient.blogPosts(JumblrClient.java:173)


[jackie-scholl]

This might be due to the restrictions on reflection in GAE; see the restrictions at https://developers.google.com/appengine/docs/java/#The_Sandbox and a description of the problem (but serializing instead of deserializing) at http://stackoverflow.com/a/3007044/1772907. The suggested solution, I believe, was to write a custom deserializer.

[KevinTCoughlin]

Closing this for now as it is indeed a limitation of GAE. Would welcome a PR for using a custom de/serializer if the need is there.