bootrun compilation error

I get the following error when trying to run the AppConfig.java file using bootrun:

`23:21:40: Executing external task 'bootRun'... :compileJava UP-TO-DATE :processResources UP-TO-DATE :classes UP-TO-DATE :findMainClass :bootRun FAILED

FAILURE: Build failed with an exception.

What went wrong: Execution failed for task ':bootRun'. No main class specified

Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED`

Edit: Added code to give some context:

This is the AppConfig.java file code:

package com.rredondo.gifTeamTreeHouse;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;

@EnableAutoConfiguration
class AppConfig
{
public void main(String []args)
{
SpringApplication.run(AppConfig.class, args);
}
}

This is the build.gradle file code:

group 'com.rredondo'
version '1.0-SNAPSHOT' buildscript{
repositories{
mavenCentral()
}
dependencies{
classpath 'org.springframework.boot:spring-boot-gradle-plugin:1.2.6.RELEASE'
}
}
apply plugin: 'java'
apply plugin: 'spring-boot'
sourceCompatibility = 1.8
repositories {
mavenCentral()
}
dependencies {
compile 'org.springframework.boot:spring-boot-starter-thymeleaf'
}