Package jadex.commons.beans

Class PersistenceDelegate

  • Direct Known Subclasses:
    DefaultPersistenceDelegate
    public abstract class PersistenceDelegate
extends java.lang.Object
    PersistenceDelegate instances write received bean objects to encoders in the form of expressions and statements, which can be evaluated or executed to reconstruct the recorded bean objects in a new environment during decoding. Expressions are usually used to instantiate bean objects in the new environment, and statements are used to initialize their properties if necessary. As a result, the reconstructed bean objects become equivalent to the original recorded ones in terms of their public states.

    • Constructor Summary

      Constructors 
      Constructor Description
      PersistenceDelegate()
      Default constructor.

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      protected void initialize​(java.lang.Class<?> type, java.lang.Object oldInstance, java.lang.Object newInstance, Encoder enc)
      Produces a series of expressions and statements for the initialization of a bean object's properties.
      protected abstract Expression instantiate​(java.lang.Object oldInstance, Encoder enc)
      Constructs an expression for instantiating an object of the same type as the old instance.
      protected boolean mutatesTo​(java.lang.Object o1, java.lang.Object o2)
      Determines whether one object mutates to the other object.
      void writeObject​(java.lang.Object oldInstance, Encoder out)
      Writes a bean object to the given encoder.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • PersistenceDelegate

        public PersistenceDelegate()
        Default constructor.

    • Method Detail

      • initialize

        protected void initialize​(java.lang.Class<?> type,
                          java.lang.Object oldInstance,
                          java.lang.Object newInstance,
                          Encoder enc)
        Produces a series of expressions and statements for the initialization of a bean object's properties. The default implementation simply invokes the initialization provided by the super class's PersisteneceDelegate instance.
        Parameters:
        type - the type of the bean
        oldInstance - the original bean object to be recorded
        newInstance - the simmulating new bean object to be initialized
        enc - the encoder to write the outputs to

      • instantiate

        protected abstract Expression instantiate​(java.lang.Object oldInstance,
                                          Encoder enc)
        Constructs an expression for instantiating an object of the same type as the old instance. Any exceptions occured during this process could be reported to the exception listener registered in the given encoder.
        Parameters:
        oldInstance - the old instance
        enc - the encoder that wants to record the old instance
        Returns:
        an expression for instantiating an object of the same type as the old instance

      • mutatesTo

        protected boolean mutatesTo​(java.lang.Object o1,
                            java.lang.Object o2)
        Determines whether one object mutates to the other object. One object is considered able to mutate to another object if they are indistinguishable in terms of behaviors of all public APIs. The default implementation here is to return true only if the two objects are instances of the same class.
        Parameters:
        o1 - one object
        o2 - the other object
        Returns:
        true if second object mutates to the first object, otherwise false

      • writeObject

        public void writeObject​(java.lang.Object oldInstance,
                        Encoder out)
        Writes a bean object to the given encoder. First it is checked whether the simulating new object can be mutated to the old instance. If yes, it is initialized to produce a series of expressions and statements that can be used to restore the old instance. Otherwise, remove the new object in the simulating new environment and writes an expression that can instantiate a new instance of the same type as the old one to the given encoder.
        Parameters:
        oldInstance - the old instance to be written
        out - the encoder that the old instance will be written to