Update gwt-module.dtd

Question

i use java compiler 1.8 i use installed JREs jdk-17 when compiling maven packages from batch file or in Eclipse with call mvn clean install

i get this error

[INFO] Compiling module mleWidgeset.MLEWidgetset
[INFO]    [ERROR] Hint: Check that your module inherits 'com.google.gwt.core.Core' either directly or indirectly (most often by inheriting module 'com.google.gwt.user.User')

so I do a bit of scouting on this platform like

GWT - Module.gwt.xml - XML validation warning GWT Error: There is '1' error in 'gwt-module.dtd'

I find that the .xml files need to be updated to update the gwt DTD modules so i update these references

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC "-//Google Inc.//DTD Google Web Toolkit 
2.5.1//EN" "http://google-web- 
toolkit.googlecode.com/svn/tags/2.5.1/distro-source/core/src/gwt- 
module.dtd">

with these

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC "-//Google Inc.//DTD Google Web Toolkit 
2.9.0//EN" "http://www.gwtproject.org/doctype/2.9.0/gwt-module.dtd">

but i get this error in all projects where updated .xml files like above

enter image description here

Can you help me understand how to fix it? the gwt dtd file link is correct, putting it in chrome browser downloads the DTD file

Answer 1

GWT doesn't require the "?xml" and "!DOCTYPE" lines, so you can just remove them. Also, "user.User" inherits "core.Core", so you can remove the last one.

Anyway, the error doesn´t seem related to the DTD. If you have updated GWT version, you may have mixed version in the classpath. And if you have updated the JDK version, then maybe you need to use the last GWT release.

Maybe it is better to use gitter#gwt to solve your doubt.