Module: Java

Defined in:

lib/javaobs.rb

Overview

Java Objects namespace to read and write Java serialized objects to streams. Any Java serialized object can be read from a stream. To write a Java object, the meta class must be primed with a sample input serialized object. The is required because Java uses a UUID to identify classes and it is generated using a complex hashing scheme of data and method signatures. Since this system does not have access to that information, it needs to get it from a serialized object.

Objects that have custom serialization methods can be read and written by creating a class as we have for the Date class:

class Date < SimpleDelegator
  extend JavaObject

  def initialize
   super(Time)
  end

  def time=(time)
    case time
    when Time
      __setobj__(time)

    when String
      t, = time.unpack("Q")
      __setobj__(Time.at(t / 1000, (t % 1000) * 1000))
    end
  end

  def data
    t = __getobj__.tv_sec * 1000 + __getobj__.tv_usec / 1000
    [t].pack("Q")
  end
end

The important methods are the data method that is used for writing the the object to a stream.

All other classes will be auto-generated when the stream is read and persisted. A Java Meta Class is added to the Ruby Class that contains all the Java field information needed to serialize the objects.

Defined Under Namespace

Modules: JavaObject, ObjectStream Classes: Date, JavaArray, JavaClass, JavaField, ObjectInputStream, ObjectOutputStream, SerializationError