Execution failed for task ':findMainClass'.

直接上错误信息

D:\devops\learn\SpringBootDemo>gradle build -x test
> Task :findMainClass FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':findMainClass'.
> org.gradle.api.tasks.SourceSetOutput.getCla

* Try:
Run with --stacktrace option to get the stack
option to get more log output. Run with --sca

* Get more help at https://help.gradle.org

BUILD FAILED in 2s
4 actionable tasks: 1 executed, 3 up-to-date

解决办法：
在build.gradle中添加如下代码：

apply plugin: 'application'


mainClassName = 'com.xxx.xxx.xxx.xxxApplication'

重新编译即可
下面给出完成的build.gradle脚本

buildscript{
   ext{
     sprintBootVersion = '1.5.1.RELEASE'
   }
   repositories{
     maven {url "http://maven.aliyun.com/nexus/content/groups/public/"}
   }
   dependencies{
     classpath("org.springframework.boot:spring-boot-gradle-plugin:${sprintBootVersion}")
   }   
}

apply plugin: 'application'
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'

mainClassName = 'com.xxx.xxx.xxx.SpringBootDemoApplication'

group = 'com.hezs.learn.springboot'
version = '0.0.1-SNAPSHOT'

jar{
   baseName = 'springbootdemo'
   version = '1.0.0'
}

sourceCompatibility = 1.8
targetCompatibility = 1.8


repositories { 
  maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
} 


dependencies {
	compile "org.springframework.boot:spring-boot-starter-amqp:${sprintBootVersion}"
	compile "org.springframework.boot:spring-boot-starter-data-jpa:${sprintBootVersion}"
	compile "org.springframework.boot:spring-boot-starter-thymeleaf:${sprintBootVersion}"
	compile "org.springframework.boot:spring-boot-starter-web:${sprintBootVersion}"
	compile "org.springframework.boot:spring-boot-starter-data-redis:${sprintBootVersion}"
	compile "mysql:mysql-connector-java:6.0.3"
	compile "org.flywaydb:flyway-core:3.2.1"
	annotationProcessor 'org.projectlombok:lombok:1.16.12'
	testCompile "org.springframework.boot:spring-boot-starter-test:${sprintBootVersion}"
}