Gradle 4.7 build throw error executing task bootRepackage - spring-boot

Question

While executing gradle build command in my existing spring boot project which was / is building fine with older version of Gradle (For ex: 3.4.*).
But after I upgraded Gradle to latest version (4.7) using SDK, its started throw error while building.
Config List:
------------------------------------------------------------
Gradle 4.7
------------------------------------------------------------
Build time: 2018-04-18 09:09:12 UTC
Revision: b9a962bf70638332300e7f810689cb2febbd4a6c
Groovy: 2.4.12
Ant: Apache Ant(TM) version 1.9.9 compiled on February 2 2017
JVM: 1.8.0_121 (Oracle Corporation 25.121-b13)
OS: Linux 3.16.0-4-amd64 amd64
Spring Boot Details:
springBootVersion = '1.5.1.RELEASE'
classpath "org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}"
build.gradle Note: I can't publish whole build file. So giving some import lines to analyse.
buildscript {
ext {
springBootVersion = '1.5.1.RELEASE'
}
repositories {
mavenCentral()
jcenter()
}
dependencies {
classpath "org.springframework.boot:spring-boot-gradle- plugin:${springBootVersion}"
}
}
subprojects {
apply plugin: 'groovy'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
apply plugin: 'com.jfrog.artifactory'
apply plugin: 'maven-publish'
apply plugin: 'war'
apply plugin: 'org.sonarqube'
// make sure bootRepackage is included in task graph
project.tasks.findAll { it.name.startsWith("artifactory") } .each { it.dependsOn assemble }
// so we can maintain both "normal" and "boot" jars
springBoot {
classifier = 'boot'
}
publishing {
publications {
mavenJava(MavenPublication) {
// from components.java
// "boot" jar
artifact ("$buildDir/libs/${project.name}-${version}-boot.war") {
classifier = 'boot'
}
}
}
}
def profiles = 'development'
bootRun {
args = [
"--spring.profiles.active=" + profiles
]
}
defaultTasks 'bootRun'
// Other tasks and dependency list
}
Output from Command Line:
gradle build
Task :test-service:bootRepackage FAILED
> FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':test-service:bootRepackage'.
> Unable to find main class
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
Deprecated Gradle features were used in this build, making it incompatible with Gradle 5.0.
See https://docs.gradle.org/4.7/userguide/command_line_interface.html#sec:command_line_warnings

Answer 1

Spring Boot 1.5.x only supports Gradle 2 (2.9 or later) and Gradle 3. Gradle 4 is not supported.
You could either stick with Gradle 3.x or upgrade to Spring Boot 2.0.x which does support Gradle 4.

Answer 2

The error clearly states that -
* What went wrong:
Execution failed for task ':test-service:bootRepackage'.
> Unable to find main class
Please check if you have entry similar in your build.gradle
apply plugin: 'application'
mainClassName = 'com.my.MyApplication' // your application main class goes here

Answer 3

According to this question, you have to set the main class :
bootRepackage {
mainClass = 'your.app.MainClass'
}