EAServer’s IDL compiler extends IDL to allow Java class names as parameter and return types for methods. This feature provides functionality that is similar to the proposed Objects by Value CORBA extension (OMG TC Document orbos/98-01-18, Objects By Value). Specifically, you can pass a copy of an object rather than passing an interface pointer that refers back to the original object.
You can specify any Java class name for a method input parameter or return type as long as:
The class containing the type name is in the CLASSPATH environment variable both when the interface is defined and when the server is run.
At run time, you specify a class instance that is serializable. That is, a class must implement the java.io.Serializable interface or inherit from another class that does so, and an interface must extend the java.io.Serializable interface. If the instance is not serializable, the call fails with a CORBA::MARSHALL exception.
Note the following restrictions for methods that are defined using Java datatypes rather than IDL types:
Only Java components can implement the method and only Java clients can invoke the method.
Only in parameters and return values can be declared with Java class names.
Java datatypes are not marshaled as efficiently as an equivalent IDL datatype. Marshaling is the process of reading and writing parameters and return values from the network. More bytes are required to marshal values defined with a Java datatype than to marshal an equivalent IDL type. Consequently, invocations of a method defined with Java datatypes are slower than invocations of an equivalent method defined with IDL datatypes.
IDL that contains Java class names may not be portable to other CORBA client ORB implementations unless they offer this extension to standard CORBA IDL.
