Hi Jasper
I'll be just glad if my current progress saves someone's time.
I progress on step by step basis, so far I succeeded in Eclipse build and
debugging.
Most of my problems were caused by combination of JDK11+ (namely modules) +
Gradle + Eclipse + Eclipse GWT Plugin.
Reason: GWT SDK gwt-dev.jar contains lot of classes that must not be
visible to Eclipse compiler, but in fact they are, causing dreaded "The
package org.w3c.dom is accessible from more than one module: ,
java.xml" error.
When `gradle build` is issued in command line the gwt-dev.jar from the
maven repository is linked, it contains exactly essential google classes
and nothing more. Thus the build succeeds.
But when you import such project in Eclipse under JDK11+ (I use JDK17) and
select a GWT SDK there're lots of build errors caused by "The package is
accessible from more than one module"
Reason: To run devmode or compilation server in Eclipse via Eclipse GWT
plugin, you need full-blown gwt-dev.jar, so you need to install a GWT SDK
and select it in your Eclipse project. And for some reason (by design of
the Eclipse GWT plugin) this gwt-dev.jar from SDK spoils the Eclipse
compilation classpath even if the build.gradle adds a dependency to the
"essential" gwt-dev.jar
Indeed the Eclipse GWT Plugin allows to use an "essential" gwt-dev.jar from
project dependencies instead of a real GWT SDK (even without installing it
and registering in Eclipse), but *only for Maven projects*. Gradle is not
covered.
My solution was to patch an existing GWT SDK:
1. prepare GWT SDK
assuming we have it installed into gwt-2.9.0 folder:
mv gwt-2.9.0 gwt-2.9.0-jdk11
cd gwt-2.9.0-jdk11
rename full blown gwt-dev
mv gwt-dev.jar gwt-dev-rundevserver-full.jar
then assuming we already have dependencies stored in cache let's get the
"essential" jar
cp ~/.m2/repository/com/google/gwt/gwt-dev/2.9.0/gwt-dev-2.9.0.jar
gwt-dev.jar
it will leak to Eclipse build classpath but it's jdk11-conformant (or
rather Jigsaw conformant)
2. add the patched GWT SDK (its folder name *gwt-2.9.0-jdk11* is used as
its name) to Eclipse project via maven, so it will be already bound after
project import
eclipse.classpath {
containers
"com.gwtplugins.gwt.eclipse.core.GWT_CONTAINER/gwt-2.9.0-jdk11"
}
3. Fix compilation server launcher
Let's refer the full-blown jar in launcher started by GWT Plugin:
Add a web server to eclipse (Tomcat or another one),
add your webapp to the server (at this moment I usually set server start
timeout to really long interval and uncheck the webapp "autoreloading
enabled" to avoid webapp relaunch on hot code replace),
then click "debug server" button:
-> compilation server launcher config will be created, your webapp and
the compilation server will launch but the latter will fail because the
gwt-2.9.0-jdk11/gwt-dev.jar only contains skeleton files
Stop the webapp
Edit the compilation server configuration:
Edit classpath adding GWT_SDK_HOME/gwt-dev-rundevserver-full.jar as
external jar to the [User entries] as the last entry:
[image: image_2022-02-19_013438.png]
"Debug server" once more: the compilation server must start and work now.
The debugger and hot code replace for server classes will work as they
should, and the changes to client java GWT files will be promptly
recompiled when you refresh the page. It works in web server of your
choice, not in Jetty bundled with GWT SDK.
And click-through / debugging into XML/Servlet classes no more opens java
bytecode in fullblown gwt-dev.jar but proper source files of JDK or your
dependencies.
Hope this helps
Tequilacat
среда, 16 февраля 2022 г. в 06:12:23 UTC+1, blackh...@gmail.com:
> Hi ,
>
> You mention that you are migrating from jdk 1.8 to jdk 17.
> We are in the same process, any tips you have?
>
> regards,
>
> Jasper
>
> Op dinsdag 15 februari 2022 om 22:30:30 UTC+1 schreef tequil...@gmail.com:
>
>> Hi,
>>
>> > You're all set; the plugin will use the GWT dependencies from the Maven
>> project.
>>
>> The question - can I configure it with gradle?
>>
>> I'm porting a GWT gradle-based Eclipse project from JDK 1.8 to JDK 17
>> (and from 2.8.2 to 2.9.0)
>> In Eclipse, there's typical JDK11+ error "The package org.xml.sax.helpers
>> is accessible from more than one module" and it looks like the org.xml.sax
>> classes shipped in gwt-dev.jar clash with jdk. Eclipse compiler somehow
>> refers gwt-dev.jar.
>> Command line gradle build succeeds OK.
>> If maven-central version of gwt-dev doesn't contain duplicating classes
>> it would save the day.
>>
>> Is there a way to configure *gradle* project to force Eclipse plugin to
>> use GWT version from gradle dependencies?
>>
>> I have GWT 2.9.0 installed and added in Eclipse. To avoid referring this
>> all-inclusive gwt-dev I removed GWT-2.9.0 from list of GWT SDKs in Eclipse
>> settings, and now after importing/refreshing my gradle project the GWT
>> plugin SDK selection doesn't
