In most cases, Visual J# provides a simple upgrade experience for Visual J++ projects. However, you should ensure that your project is building and running successfully in Visual J++ before attempting to upgrade. You should also set the active configuration of the Visual J++ project to Release and verify that the application is running before upgrading. This will result in an easier upgrade.
There are some features in Visual J++ which are not supported in Visual J#, or have compatibility issues in Visual J#. See Class Library Support and Language Support to determine possible work that may be required to get your application running successfully in Visual J#. Common Issues in Upgrading Projects from Visual J++ 6.0 lists a number of issues that you may encounter in upgrading your application.
The Upgrade Wizard sets project properties and references for COM and .NET components based on your input, as well as the analysis of the project files. For very large projects, analysis may take some time, comparable to the time required to build the upgraded project. Although the wizard allows you to skip the analysis step by clicking the Finish button, it is recommended that you do not. The upgrade report that is created by the wizard identifies many of the issues in getting your application successfully running on Visual J#. This list of issues may be useful in determining the amount of work required to upgrade successfully.