Could not get unknown property 'mainClass' for object of type org.springframework.boot.gradle.dsl.SpringBootExtension. about gretty

[javabrett]

@tiemei @rssdev10 is there a test for this and/or a pull-request? Note that Spring Boot 2.x has now been merged to master so it would be good to get a failing->passing test and PR for this change if still relevant.

[rssdev10]

Hi, I merged yours 2.3.0-release branch into my repo and tried to rerun Boot2 app. It is not working but for now the reason is

Caused by: java.lang.ClassNotFoundException: org.eclipse.jetty.server.session.HashSessionManager
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 41 more
Exception in thread "Thread-27" org.gradle.process.internal.ExecException: Process 'command '/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/bin/java'' finished with non-zero exit value 1
        at org.gradle.process.internal.DefaultExecHandle$ExecResultImpl.assertNormalExitValue(DefaultExecHandle.java:395)
        at org.gradle.process.internal.DefaultJavaExecAction.execute(DefaultJavaExecAction.java:37)
        at org.gradle.api.internal.file.DefaultFileOperations.javaexec(DefaultFileOperations.java:192)

I'm using very simple test. It is almost empty demo Boot2 app from https://start.spring.io/ with included gretty.

demo-spring-boot-2_gretty-2-3 2.zip

[weleoka]

The error is occuring for my running of Gretty tasks and building for a Spring MVC project. Boot is version 2.1.5. Gradle 5.4.1.

If it is the case that springBoot=true in gradle.build is needed in order for Gretty to work with Spring, then currently the dependency for gretty-springboot-2.3.x is failing.

The Gretty readme says the latest changes: "Bumped Spring Boot version to 1.5.9 (was 1.5.4)." for May 21, 2018, Gretty(.org) 2.2.0.

There are several ways to specify mainClass in Gradle. https://docs.spring.io/spring-boot/docs/2.1.5.RELEASE/gradle-plugin/reference/html/#packaging-executable-configuring-main-class

[golinko]

Have the same issue as @weleoka , but for SpringBoot 2.1.6.RELEASE and Gradle 5.6.2

The commit mentioned by @tiemei should fix the problem with mainClass which is not present in springBoot properties anymore.

What needs to be done in order to release the fix?