Problems with installation of Vaadin8 in Eclipse

Question

I'd like to install Vaadin 8 in a fresh Eclipse IDE

So I downloaded Eclipse [Oxygen.2 Release (4.7.2) Build id: 20171218-0600], installed it, and from Help/Eclipse Marketplace I loaded the Vaadin Eclipse Plugin 4.0.0.final (changed to 4.0.1 somewhere on the way)

Attempt1: Vaadin Docs refer to videos which didn't help: Create new project, enter vaadin-archetype-application, ... Doesn't work: Eclipse doesn't find the archetype, and thus doesn't create a project
Attempt 2: Create Vaadin 8 project. This one seems to find the above archetype and creates a project called myapplication, but it has compile errors: Eclipse can't resolve the Vaadin Classes like UI, Button, VaadinRequest etc

Any help or hint is apprecated!

In attempt 2 Eclipse complains about the POM (red markers):

Project build error: Non-resolvable parent POM for com.vaadin:vaadin-bom:8.3.1: Failure to transfer com.vaadin:vaadin-parent:pom:1.1.0 from https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced. Original error: Could not transfer artifact com.vaadin:vaadin-parent:pom:1.1.0 from/to central (https://repo.maven.apache.org/maven2): repo.maven.apache.org
Project build error: 'dependencies.dependency.version' for com.vaadin:vaadin-server:jar is missing. This is what the dependency looks like in the pom.xml which was generated:
```
<dependency>
    <groupId>com.vaadin</groupId>
    <artifactId>vaadin-server</artifactId>
</dependency>
```
Same error for: vaadin-push, vaadin-client-compile and vaadin-themes

Also maybe check out https://start.spring.io/ which can create a maven project — Adder, Feb 22 '18 at 15:34
Yes, in attempt 2 Eclipse created a Maven project, but with compile errors as descibed under "Attempt 2" above. — Martin Rösch, Feb 22 '18 at 17:01
Check your .m2 folder for the jar files. You might need to manually delete them and then maven update — Jay, Feb 22 '18 at 21:01
What version number is used for vaadin-spring-boot in the pom.xml? — Adder, Feb 23 '18 at 08:17
@Jay Thank you for your hint, which I have not followed because I have a clean Eclipse install. If I had to manually delete files in order to get it running, I'd rather not trust it. — Martin Rösch, Feb 23 '18 at 10:31
@Jay: Thank you for the explanation about the .m2 folder. I didn't know it is used by Maven as a cache, independent from Eclipse. — Martin Rösch, Feb 23 '18 at 14:02

score 0 · Answer 1 · answered Feb 23 '18 at 12:05

Problem solved. Found 2 solutions.

Solution 1: Installed IntelliJ. From the above mentioned error message 'Failure to transfer ...', got the idea that https://repo.maven.apache.org/maven2/ might be a URI to try. IntelliJ presents clear concepts, and thus helped me to find the archetype 'archetype-vaadin-application', under GroupId 'com.vaadin'. So I got a clean compile. Had to guess that the field Command line in the run configuration didn't want the command line content 'mvn jetty:run' but just the goal 'jetty:run'. Then the program ran. Done.
Solution 2: In Eclipse (w/ Vaadin Plug-in). New / Project ... / Maven / Maven Project / Next > / Next > / Configure ... (Catalogs). Added Remote Catalog. Catalog file: https://repo.maven.apache.org/maven2/, named it 'Maven Repository'. OK. Brought me back to Window 'New Maven Project'. Chose the name I just invented 'Maven Repository', and some 20.000 archetype appeared. Entered filter 'vaadin' which reduced the list to around 20. Picked 'archetype-vaadin-application'. Got clean compile, but no run config. Created one, chose my Workspace, guessed jetty:run as goal. Build failed. Complained about using a JRE instead of a JDK (jre1.8.0_161). Searched for a place to enter a JDK. Found none. Clicked 'Environments ...', chose JavaSE-1.8, checked jre1.8.0_161 (only choice), ran again. Now the JRE apparently was accepted as JDK. Build was ok. Program ran. Done.

Conclusion:

Vaadin is a great tool, but its installation documentation is incomplete and misleading.
I will stop using Eclipse, after 16 years. IntelliJ is conceptually much clearer: Using IntelliJ taught me how to make Eclipse do what I needed.

I don't think your assessment is fair. There's no "install" of Vaadin into your IDE since you're supposed to use Maven, Gradle or similar. I would argue that 80-90% of all Java projects use Maven or Gradle and therefore it can hardly be the job of Vaadin docs to explain how this works. Another issue you've run into: Eclipse's support for Maven has - IMO - always been far behind that of NetBeans or IntelliJ. Again, this has nothing to do with Vaadin. — peterh, Feb 25 '18 at 13:19
Hi Peter, I tried to follow the Vaadin 8 tutorial and it mentioned only installing Eclipse and a JDK. Nothing else. No word about Maven. No word about the Vaadin Plugin. I cannot judge whose fault it is. I only know it doesn't work as described on the Vaadin website. This complaint is still valid today, 11 months later. Only difference: I do not get a clean compile anymore. All the imports of com.vaadin. fail. Also not mentioned in the tutorial. — Martin Rösch, Jan 15 '19 at 22:41

Problems with installation of Vaadin8 in Eclipse

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