10.2.6. 例

public class Array extends StateManager
{
    public Array ();
    public Array (Uid objUid);
    public void finalize ( super.terminate(); };
      
    /* Class specific operations. */
      
    public boolean set (int index, int value);
    public int get (int index);
      
    /* State management specific operations. */
      
    public boolean save_state (OutputObjectState os, int ObjectType);
    public boolean restore_state (InputObjectState os, int ObjectType);
    public String type ();
      
    public static final int ARRAY_SIZE = 10;
      
    private int[] elements = new int[ARRAY_SIZE];
    private int highestIndex;
};

public class Array extends StateManager
{
    public Array ();
    public Array (Uid objUid);
    public void finalize ( super.terminate(); };
      
    /* Class specific operations. */
      
    public boolean set (int index, int value);
    public int get (int index);
      
    /* State management specific operations. */
      
    public boolean save_state (OutputObjectState os, int ObjectType);
    public boolean restore_state (InputObjectState os, int ObjectType);
    public String type ();
      
    public static final int ARRAY_SIZE = 10;
      
    private int[] elements = new int[ARRAY_SIZE];
    private int highestIndex;
};

/* Ignore ObjectType parameter for simplicity */

public boolean save_state (OutputObjectState os, int ObjectType)
{
    if (!super.save_state(os, ObjectType))
	return false;
      
    try
	{    
	    packInt(highestIndex);

	    /*
	     * Traverse array state that we wish to save. Only save active elements
	     */

	    for (int i = 0; i <= highestIndex; i++)
		os.packInt(elements[i]);
      
	    return true;
	}
    catch (IOException e)
	{
	    return false;
	}
}
      
public boolean restore_state (InputObjectState os, int ObjectType)
{
    if (!super.restore_state(os, ObjectType))
	return false;
      
    try
	{
	    int i = 0;
      
	    highestIndex = os.unpackInt();
      
	    while (i < ARRAY_SIZE)
		{
		    if (i <= highestIndex)
			elements[i] =  os.unpackInt();
		    else
			elements[i] = 0;
		    i++;
		}
      
	    return true;
	}
    catch (IOException e)
	{
	    return false;
	}
}
      
public String type ()
{
    return '/StateManager/Array';
}

/* Ignore ObjectType parameter for simplicity */

public boolean save_state (OutputObjectState os, int ObjectType)
{
    if (!super.save_state(os, ObjectType))
	return false;
      
    try
	{    
	    packInt(highestIndex);

	    /*
	     * Traverse array state that we wish to save. Only save active elements
	     */

	    for (int i = 0; i <= highestIndex; i++)
		os.packInt(elements[i]);
      
	    return true;
	}
    catch (IOException e)
	{
	    return false;
	}
}
      
public boolean restore_state (InputObjectState os, int ObjectType)
{
    if (!super.restore_state(os, ObjectType))
	return false;
      
    try
	{
	    int i = 0;
      
	    highestIndex = os.unpackInt();
      
	    while (i < ARRAY_SIZE)
		{
		    if (i <= highestIndex)
			elements[i] =  os.unpackInt();
		    else
			elements[i] = 0;
		    i++;
		}
      
	    return true;
	}
    catch (IOException e)
	{
	    return false;
	}
}
      
public String type ()
{
    return '/StateManager/Array';
}