eclipse JUNO hangs on start up

I use Eclipse JUNO every day.  However, I couldn't start it today after I restart my Mac.  Mac updated with Microsoft 2011 so I have to reboot Mac machine.  The strange thing happened: Eclipse got stuck.  I manually killed the start up process several times, but it didn't work.  Then I googled it, and found the solution from this post, and here is what I did:

rm $WORKSPACE_DIR/.metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi

Then I can start eclipse, and happy coding.  

Eclipse: fix plugin execution not covered by lifecycle configuration

I recently used maven-jaxb2-plugin to generate java classes based on xml schemas (xsd).  I can run "mvn compile" on command line to generate java classes with the following configuration:
            <plugin>
                <groupId>org.jvnet.jaxb2.maven2</groupId>
                <artifactId>maven-jaxb2-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
However, my Eclipse shows the following error:

Plugin execution not covered by lifecycle configuration: org.jvnet.jaxb2.maven2:maven-jaxb2-plugin:0.8.1:generate (execution: default, phase: generate-sources)


This error prevents Eclipse generating java source codes and adding the generated sources to the class path.  In order to fix this problem, I need to install m2e connector for maven-jaxb2-plugin.  I can manually install it to Eclipse with the following update site:

http://bitstrings.github.com/m2e-connectors-p2/milestones/

However, Eclipse provides a better to install it.  Eclipse shows the problem with the following:

Roll the mouse over <execution>, it displays the following:

Click the link "Discover new m2e connector", and eclipse will try to find the correct  connector automatically:

Eclipse found the same m2e connector.  Click finish to install it.  After I installed it successfully, Eclipse is happy with maven-jaxb2-plugin.

This approach can be applied to other plugins too.