Project lombok is used in Java projects to generate methods and classes, it is triggered during build time. When using the Eclipse JDT Language Server in combination with eglot in Emacs via eglot-java JTDLS needs to be configured to have lombok available to generated the needed classes at compile time as JTDLS does not trigger a maven or Gradle built which would handle the generation. To do this, configure the Eglot Java Eclipse Jdt Args to include the lombok jar, available at Project lombok.
When saving in custom.el this can look like this
'(eglot-java-eclipse-jdt-args
'("-Xmx4G" "--add-modules=ALL-SYSTEM" "--add-opens" "java.base/java.util=ALL-UNNAMED" "--add-opens" "java.base/java.lang=ALL-UNNAMED" "-javaagent:/Users/phil/.emacs.d/share/lombok/lombok.jar" ...))
only the -javaagent is required, but increasing the -Xmx to 4G has been useful for me for big projects.
Code from the sideline 