SAP JCo Migration 2.x-3.0 (Standalone) 
A few SAP JCo features have been improved for version 3.0 of SAP JCo. In contrast to previous versions, version 3.0 now offers the following advantages:
Improved supportability
Higher security
Improved resource management
Increased stability
Improved metadata concept:
– reduced memory consumption
– some of the Unicode/non-Unicode communication problems have been solved
Division of application-related and technical areas in the runtime environment
Uniform behavior of JCo applications in a specific runtime environment (for example, WebSphere)
More robust programming model for client and server
RFC Library replaced by a Java RFC implementation (reduced risk of system failure)
New Features:
Stateful server communication
Advanced monitoring functions
Complete support of ABAP statement IS_SUPPLIED
Support of data type DECFLOAT
Some clear alterations have been made to JCo API using SAP JCo Standalone Version 3.0.
To ensure that SAP JCo continues to function correctly, you will need to make some changes to the coding when switching from an older JCo version (2.x) to JCo 3.0.
Below you will find the necessary information about the type of changes that have been made and actions required for the migration.
Modifications are possibly required in the following areas:
General Changes
Connection Management
Exception Handling
Metadata Model
Server Adaptations
The scope of the changes to be made depends largely on the application scenario used. There are basically three possible scenarios:
Client Scenarios
You application communicates as a client with an ABAP server.
You application has static metadata or metadata-relevant APIs.
Server Scenarios
Your application was developed on a Java application server and executes server functions, that is it processes ABAP server calls.
You also have to make some general changes in the coding independent from the application scenario.
For more detailed information on each of the changes to be made, see:
Scenario-Independent:
Client Role:
Server Role:
For the complete documentation on client and server programming for JCo 3.0, see: