I have a multi-project gradle build with Spring Boot structured per default gradle conventions.
root
-- common
-- src/main/java
-- bootproject
-- src/main/java
My current project is to (A) upgrade gradle from 5.x to 7.3.x and (B) use embedded tomcat with Spring Boot.
This is a project that has existed for many years and is Spring Boot but has always been deployed traditionally as a WAR file in Tomcat.
I have upgraded gradle to 7.3.3 following the gradle migration guide and have "common" building correctly (java-library). I am now trying to make "bootproject" build correctly again. I have migrated my build.gradle, and compilation happens correctly now but upon executing 'gradlew sub-project:build' I get the error:
Execution failed for task ':tx-main:bootWarMainClassName'. java.lang.IllegalArgumentException (no error message)
My ROOT build.gradle is simple:
plugins {
id "org.springframework.boot" version "2.6.3"
}
subprojects {
apply plugin: 'java'
group = 'com.blah'
version = '2.1.1'
repositories {
mavenCentral()
}
There is a library sub-project (common) that builds fine.
The Spring Boot subproject build.gradle is:
plugins {
id 'org.springframework.boot'
id 'io.spring.dependency-management'
}
dependencies {
implementation project(path:':common', configuration:'default')
implementation 'org.springframework.boot:spring-boot-starter-web'
implementation ...
}
The main class was originally set up to make the app conventionally deployed (extends SpringBootServletInitializer), but has been replaced with (taken directly from docs):
package com.blah;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
The compilation works, this class appears to be in the build/classpath so I don't understand why Gradle-Spring-Boot is not finding it. I have also tried explicitly identifying the class with the same result.
Unfortunately I find little documentation about multi-project gradle builds so I suspect that is part of the problem. Hopefully someone here can point me in the right direction as to what is wrong.
Thanks