Enhydra 3.0.1 Release Notes

These release notes include:

Changes Since Enhydra 3.0

Platform, System, and Install Requirements


Platform Support

Through the open source development process, Enhydra has been used on a wide variety of platforms and with many different JDBC-supported databases, but only the specific configurations listed below are fully tested

Enhydra 3.0.1 Multiserver

Enhydra Director



Note that JREs cannot be used with Enhydra due to XMLC and JSP dynamic page re-compilation.

System Requirements

The minimum recommended system configuration is:

New Features



Application Wizard

Known Problems

Enhydra Specific

Platform Specific

Additional Notes

Multiple Connection Methods

Enhydra applications and Servlet 2.2 contexts (a "web app") can be accessed through multiple URLs. This is achieved by creating more than one connection method. In the case of Servlet 2.2 Web applications there is a restriction that each connection method must have the same URL path prefix (the port number may be different).

In general, multiple connection methods are discouraged. They are useful for providing a "special" access path to an application for debugging or for privilaged admin access to an application designed for such purposes.


The GUI interface to the Enhydra Object-to-releational mapping technology is provided as a convenience. It does not prevent the operator from creating illegal mappings that cannot be automatically built or that can cause errors in the tool. Careful use of the tool can prevent these errors. The user is envouraged to edit the DOML (XML specification file created by the DODS GUI) directly and run DODS in command line mode to avoid these problems. See the latest DODS documentation at the Enhydra.org web site.

MultiServer Debugger

When debugging Servlet 2.2 applications you may occasionally see seemingly duplicate entries. This is caused by the Servlet 2.2 internal redirection mechanism or "server side redirect" and correspond to a single client request. Each of these requests are picked up by the debugger hence the two entries.

Documentation Errata

In Getting Started with Enhydra, Chapter 4, section titled "Creating Data Objects," in following the instructions for step 3, you will encounter a known problem with the DODS GUI; it does not allow you to add data objects directly to sub-packages. So if you have:

simpleApp ( package )
   data( package )
      person( package )
          Person( data object you made )

You have to add the object Person to the data or simpleApp package and then drag it down into the person package.

In Getting Started with Enhydra, Appendix B, "Using the Multiserver Administration Console," you must perform some additional steps to manage an application with the administration console:

Reporting Bugs and Feature Requests

Send bug reports and feature requests via email to: bugs@enhydra.org.  Please include the JDK vendor, version number, operating system, and Enhydra version.