I am having the same problem.
Did you ever figure this out?
At first I was just using the default serialization but for some reason most of the properties of my classes were not getting sent across the wire.
The classes were getting set to the correct type though.
So then I implemented IExternalizable on both Flex and Java side which cause even weirder problems.
Now the remoting packet gets totally mangled.
I am using Charles and it shows the actual object in the request as being null and then random other properties of the request like the headers are getting set to the values from the DTO I am trying to send across the wire.
I can't figure out what is wrong with it.
Been stuck for like a week.
I made a simple test class and it works fine using the default serialization.
ya this was due to my stupidity...
there were two methods: write(int x) and writeInt(int x). The first one
writes only a byte from x whereas the later one writes the entire int. My
problem was that I didn't realize the type and did write(int x) on one side
and did readInt() on the other side. The serializer ran out of bytes to read
and had that null pointer.
as for your problem, I'm not really sure =/
Turns out it was my stupidity too.
I was using readObject and writeObject for long values instead of readLong/writeLong on the Java side and readDouble/writeDouble on the flex side.