There are lots of ways to create UML projects and even more ways to write code, including standing at a whiteboard. But it isn't just a question of how to capture this information, it is what you can do with it once it has been created. Poseidon's integration into the Eclipse IDE means that the most intuitive UML tool can exchange data directly with one of the most flexible development environments. Code and model become integrated into one project.
Throughout the development process, both the UML model and the source code evolve and grow. Optimally, the two should always be synchronized. Previously this meant importing and exporting changes between tools based on a common denominator. Now with the push of a single button, Eclipse and Poseidon can seamlessly integrate the textual information that is Eclipse's specialty with the visual data Poseidon is expert at creating into one comprehensive project.
This is not a comprehensive guide to Eclipse, but highlights some of the more important features of Eclipse that are relevant to Poseidon. More information about Eclipse, including download mirrors, is available at the Eclipse Website. Full Eclipse Documentation is also available.
Installing Poseidon for use within Eclipse is very simple. Before you begin, be sure that you have Eclipse correctly installed on your machine and that Eclipse is not currently running.
Install Poseidon PE .x normally, as described in the Section called Community, Standard, Professional, and Embedded Editions in Chapter 3. Start Poseidon.
From the Poseidon Plug-Ins menu, select 'Install Eclipse-Bridge'.
Select your Eclipse installation directory, then click 'Install'.

A confirmation dialog will appear. Click 'OK'.

Shut down Poseidon and start Eclipse.
If you do not have write permissions for the Eclipse directory, a new file will be placed in a temporary directory and you will be reminded to manually move this file into the 'links' directory under the Eclipse installation directory. Alternatively, you may run Poseidon with Administrator privileges.
Increasing Memory
To increase the memory available to Eclipse, start Eclipse by running "eclipse -vmargs -Xmx512m", where the number 512 can be replaced with the amount of memory to be allocated to Eclipse. Providing more memory is recommended.
Running Linux
On Linux, Eclipse needs Java 5.0 to work properly. Set the environment variable JAVA_HOME to your Java 5.0 installation directory and make sure that the PATH environment variable contains $JAVA_HOME/bin. You can verify your Java installation by checking that the command "java -version" returns a text containing "build 1.5".
Importing files has changed in Java 5.0. The changes are outlined in the Section called Importing Source Code.