The migration strategy of Struts 1 developers moving to Struts 2 involves four non-exclusive paths:
requests s and let S1 handle
requests. S1 and S2 can run side by side, within the same web application. Teams can implement new features in the latest version, and migrate older pieces as needed. Optionally, some common resources may be shared between S1 and S2, like messages, validation rules, and Tiles configurations, making for an even smoother migration.
web.xmland S1 configuration files, and generates the corresponding S2 classes, pages, and configuration files. While 100% compatibility is unlikely, we could make a strong effort to convert the application, marking areas that need attention. Comparing the converted files with the originals could also serve as a training tool.
This page originally adopted from http://wiki.apache.org/struts/MigrationStrategy.