Catherine Tornabene
CHAIMS Project
README	
RMI Wrappers 1.0 - How To Wrap
June 19, 1998


In this README, I will discuss the steps necessary to wrap a
megamodule.  Since some of the changes will need to be customized,
this is intended as a general guide.  Exact steps will be specific to
the wrapped megamodule. 

The best guides are probably the files FirstTestWrapper.java,
SecondTestWrapper.java, and NaoParameterObject.java.  These are the
customized files that I used to wrap the TestObject server.

The customized wrapper classes, FirstTestWrapper.java and
SecondTestWrapper.java extend the class LocalMethodWrapper.java.  The
LocalMethodWrapper class is abstract, which is intended to force
anybody desiring to wrap a megamodule to implement their own version
of the following methods:
	
public abstract void callMethod(ChaimsAttrValContainer c, Object obj);
public abstract byte[] convertResultToBlob();
public abstract void initializeParameters();
public abstract void initializeName();

If the megamodule method does not use any complex types, but
rather only uses boolean, integer, or String types, then the 
best model to use is the class SecondTestWrapper.  This wraps
a method that only takes and returns simple types.  Information about
the pararmeters can be stored in the ParameterObject class, in this
case, because the ParameterObject class provides type and name
checking for simple types.

However, if the local method takes complex objects as parameters,
then some further customization is necessary.  In this case,
the class FirstTestWrapper is the best model.  FirstTestWrapper
takes as a parameter the object NameAddressObject and then, after
the firstTest() method completes execution, returns a modified
NameAddressObject.  

Since NameAddressObject is a complex object, it is impossible to use
the type and name checking methods in the ParameterObject, so we
extend the ParameterObject class to create a specialized
NaoParameterObject class. (Nao = NameAddressObject).  The
NaoParameterObject overrides the method 'parameterTypeMatches(Object
o)' from its parent.  This method checks to make sure the parameter
sent via the INVOKE call is an acceptable argument to the wrapped
method.  By overriding this method, we ensure that checks on
NameAddressObject are specialized for that object.  The
NaoParameterObject also adds the call 'getComplexValue', which returns
a new NameAddressObject that contains either the default values or
the data sent via the ASN.1 package.  This is necessary to create
the new parameter to the desired method.

The best way to customize your own method wrapper is to take the
FirstTestWrapper and SecondTestWrapper classes and modify them
to make your own.