JDK and GWT Upgrade.

[Agathesh Muruganandam]

I'm looking to upgrade an ANT-based build tool project developed with Java 1.8.0.161 and GWT to utilize Java 17. To achieve this, I'm seeking guidance on the necessary modifications within the build.xml file. Additionally, I'd appreciate insights on the most suitable Apache ANT version for compatibility with Java 17 and any other crucial changes required for a smooth transition from Java 1.8 to 17. Any advice from the community on best practices and potential challenges would be greatly appreciated. Thanks in advance!

[Craig Mitchell]

We'd need more information.  If you just want to run on Java 17 and keep the source level at Java 8, that's easy.  However, if you want to move to the latest GWT version, and upgrade the source level to 17 for the server, and 11 for the client, that's a lot more work.  We were just talking about this yesterday on this thread:  https://groups.google.com/g/Google-Web-Toolkit/c/3dSoHpHD5jY

[Colin Alworth]

Do note that GWT itself is built with ant - there were no ant-specific changes we made to update GWT from Java 7/8 to 11/17/21 that we build with today.

Additionally, the GWT samples that are built with ant had no changes made at all to support newer versions of Java.

Your own usage of GWT might require some changes, but without seeing what you already have and isn't working, as Craig says, we can't guess.

[Agathesh Muruganandam]

[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'

I want to upgrade my application from Java 1.8 to jdk17. I'm getting the above mentioned error while compiling my code using jdk17.    I have used <inherits name='com.google.gwt.user.User'/> in my app.gwt.xml file. GWT Version used - 2.5.1

Build tool - ANT Note : I have used gwt-dev.jar, gwt-user-2.5.1.jar, gwt-servlet.jar in my .classpath file. Build failure is happening in my 'compile-gwt' build step.

[Colin Alworth]

GWT 2.5.1 is too old to work on Java 9+, so if you want to use a newer version of Java, you either need to update to a more recent GWT version (minimum of 2.8.2), or will need to patch your own copy of GWT to include fixes in later versions that specifically addressed these issues.