Vaadin std prod project includes vaadin-client-com

问题:

I get vaadin-client-compiler artifact (which brings Jetty with it) included with my production project. Am I supposed to ?

To reproduce I'm starting from scratch and letting Maven generate a Vaadin multimodule project for me:

mvn
-DarchetypeGroupId=com.vaadin 
-DarchetypeArtifactId=vaadin-archetype-application-multimodule 
-DarchetypeVersion=7.6.2 
-DarchetypeRepository=http://repo.maven.apache.org/maven2/ 
-DgroupId=com.acme 
-DartifactId=VaadinTest1 
-Dversion=1.0.0-SNAPSHOT 
-Dpackage=com.acme.vaadintest1 
-Dbasedir=D:\\dev\\java 
-DthemeName=mytheme 
-DwidgetsetName=MyAppWidgetset 
-DuiName=MyUI 
-Darchetype.interactive=false 
--batch-mode archetype:generate

Then in the parent project I execute:

mvn -Pproduction clean install 

After this is done I look into the WAR file generated in the "xxx-production" project and notice it contains vaadin-client-compiler, Jetty, and what not.

I've found this ticket and by looking at the last comment it seems I shouldn't have anything like that in my production WAR. I hesitate to change my POMs as they are generated by the archetype and I guess at some level supposed to represent kind of a Vaadin best-practice approach. I wouldn't want to second guess that. Or ?

The problem with these artifacts being part of the classpath is that

1. it balloons the size of the WAR
2. it creates some problems wrt Atmosphere which supposedly gets confused because it finds Jetty on the classpath. (Atmosphere is used under the hood by Vaadin)

The result is that you'll get SEVERE error like this in the log when deploying on Tomcat 8:

14-Feb-2016 16:42:30.368 SEVERE [localhost-startStop-1] org.atmosphere.cpr.DefaultAsyncSupportResolver.newCometSupport Failed to create comet support class: class org.
atmosphere.container.JettyServlet30AsyncSupportWithWebSocket, error: null

To sum up:

1. Is it correct that I'm not supposed to have these artifacts in a Vaadin 7.6.2 production project ?
2. How to solve ?

回答1:

I believe I've found the answer. It seems Vaadin team was/is fully aware of this but it is kind of a left-over from the old days when there was some kind of annoying bug.

In your xxx-widgetset project you'll see something like this in the POM for that project:

<dependencies>
    <!-- Versions for these are configured in the parent POM -->
    <dependency>
        <groupId>com.vaadin</groupId>
        <artifactId>vaadin-client</artifactId>
        <!-- TODO this should have scope provided once http://dev.vaadin.com/ticket/14788 is resolved -->
        <!-- <scope>provided</scope> -->
    </dependency>
    <dependency>
        <groupId>com.vaadin</groupId>
        <artifactId>vaadin-client-compiler</artifactId>
        <!-- TODO this should have scope provided once http://dev.vaadin.com/ticket/14788 is resolved -->
        <!-- <scope>provided</scope> -->
    </dependency>

    ... you'll see more deps here if you've added 
    ... Vaadin add-ons to your project.
</dependencies>

See the TODO comments ?? Well, it just so happens that the bug mentioned in ticket 14788 doesn't happen anymore, at least not on 7.6.2. So you can now safely do what the TODO comment says.

This has reduced my WAR size by 50-70 pct.

It seems to me there's no longer any good reason why this archetype generation doesn't actually do what TODO comment says. Currently you'll have to manually correct it every time you generate a new project skeleton.

回答2:

If you work with a different webserver (in your case Tomcat 8) you don't need the provided jetty-plugin.

As the archetype has some jetty-dependencies you can exclude them with the exclusions tag in the Maven POM file.

Example

<groupId>com.vaadin</groupId>
<artifactId>vaadin-client-compiler</artifactId>
<version>${vaadin.version}</version>
<exclusions>
    <exclusion>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-servlets</artifactId>
    </exclusion>
    <exclusion>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-annotations</artifactId>
    </exclusion>
    <exclusion>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-util</artifactId>
    </exclusion>
</exclusions>

Moreover delete/comment out all unnecessary "jetty" dependencies found in the module POM files.