Error when importing Maven-GWT project ("No marketplace entries found to handle gwt-maven-plugin") - eclipse

Question

I'm using Eclipse Indigo on Win XP, Maven 3.0.3 and GWT 2.4. I created a Maven-GWT project using the Mavne gwt archetype. Then I opened Eclipse, went to File -> Import, selected Existing Maven Projects, chose the pom for my GWT-Maven project, and then got this dialog:
The errors are
No marketplace entries found to handle gwt-maven-plugin:2.4.0:generateAsync in Eclipse. Please see Help for more information.
No marketplace entries found to handle gwt-maven-plugin:2.4.0:i18n in Eclipse. Please see Help for more information.
No marketplace entries found to handle maven-war-plugin:2.1.1:exploded in Eclipse. Please see Help for more information.
Anyone know how to resolve these errors? It is wreaking havoc when I actually import my project and try and work with it. - Dave

Answer 1

Make sure you are not using the embedded Maven of Eclipse.
Go to Window->Preference ->Maven -> Installation->choose your own maven installation folder there.
EDIT
If your company pays for IDE, you should ask for IntelliJ the IDE for Java, which I would say is better than Eclipse in many ways, not saying Eclipse is not good, that's just a good alternative. And you won't have this issue to start with

Answer 2

If your pom is not specific as to the version of the maven-resources-plugin, that version will come from the superpom. By default, m2e uses an embedded copy of Maven 3.0.x. If the superpom there points to 2.4.3 and your 'outside-of-Eclipse' version asks for something else, then the Maven inside of Eclipse will go looking for 2.4.3 and fail due to the 'offline'.
Fix by configuring m2e to use the Maven installation you are using outside, or turning off 'offline' for one build.
If you want to use maven from your local installation instead of the embedded version that comes with m2e, You have to do this
Windows ==> Preferences ==> Maven ==> Installations ==> Click Add (select your local maven installation directory)
Installation Directory is not where local repository. It is where maven is installed.
After changing try right click on project then,
Maven ----> Update Project

Answer 3

See How to solve "Plugin execution not covered by lifecycle configuration" for Spring Data Maven Builds
You can basically just copy the snippet from http://code.google.com/p/google-web-toolkit/wiki/WorkingWithMaven#POM_changes_needed_for_Eclipse_Indigo and adapt to your plugins and goals.

Answer 4

I am using a different approach with maven, gwt and eclipse.
I am using the maven eclipse plugin to generate a .classpath and .project file and import the project manually into eclipse (not as a maven project).
My configuration for the maven eclipse plugin looks like this:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.8</version>
<configuration>
<downloadSources>true</downloadSources>
<downloadJavadocs>false</downloadJavadocs>
<buildOutputDirectory>${project.build.directory}/${project.build.finalName}/WEB-INF/classes</buildOutputDirectory>
<projectnatures>
<projectnature>org.eclipse.jdt.core.javanature</projectnature>
<projectnature>com.google.gdt.eclipse.core.webAppNature</projectnature>
<nature>com.google.gwt.eclipse.core.gwtNature</nature>
</projectnatures>
<buildcommands>
<buildcommand>org.eclipse.jdt.core.javabuilder</buildcommand>
<buildcommand>com.google.gdt.eclipse.core.webAppProjectValidator</buildcommand>
<buildcommand>com.google.appengine.eclipse.core.projectValidator</buildcommand>
<buildcommand>com.google.gwt.eclipse.core.gwtProjectValidator</buildcommand>
</buildcommands>
<classpathContainers>
<classpathContainer>org.eclipse.jdt.launching.JRE_CONTAINER</classpathContainer>
<classpathContainer>com.google.gwt.eclipse.core.GWT_CONTAINER</classpathContainer>
</classpathContainers>
<excludes>
<exclude>com.google.gwt:gwt-servlet</exclude>
<exclude>com.google.gwt:gwt-user</exclude>
<exclude>com.google.gwt:gwt-dev</exclude>
<exclude>javax.validation:validation-api</exclude>
</excludes>
<linkedResources>
<linkedResource>
<name>war</name>
<type>2</type>
<location>${basedir}/target/${project.artifactId}-${project.version}</location>
</linkedResource>
</linkedResources>
</configuration>
</plugin>
Hope that helps

Answer 5

This helped me:
Delete the project from eclipse (but don't delete from disk)
Close eclipse
In your user folder there is .m folder.
Delete repository folder underneath it (.m/repository).
Open eclipse Import project as existing maven project (from disk).