Kryo Deserialization fails with “KryoException: Buffer underflow”

Question

I use Kryo to write Objects into byte arrays. It works fine. But when the byte arrays are converted into the Objects, it throws, com.esotericsoftware.kryo.KryoException: Buffer underflow. exception.

This is my deserialization:

        Kryo k=new Kryo();
        Input input=new Input(byteArrayOfObject);           
        Object o=k.readObject(input,ObjectClass.class);

Furthermore, always the object type cannot be defined in my application. At the final process, the class conversion happens. Therefore,

• How can I solve above deserialization error

• Is there a way to create Object without giving the class into readObject(...,ClassName) ?

Answer 1

This happened to me when I was not correctly closing the Output / Input types. You need to make sure Kryo flushes everything but doing output.flush() or output.close().

Second, look into kryo.writeClassAndObject(). You can then do kryo.readClassAndObject() and cast your object to the type it is supposed to be.

Answer 2

I saw this error because of a true Java serialization issue; my class definition was not the same on the producer and consumer side (two different applications) and as a result I got this exception.

Just wanted to leave this as an FYI if you hadn't checked that yet.

Answer 3

This happend to me when I used the serializer in multiple threads. It's not thread safe, so if you use it in that way, it may give you "Buffer underflow" or other exceptions.