Unable to find main class :bootRepackage

Question

I got a problem with my gradle build. I use the standard proposed by the Spring Website (https://spring.io/guides/gs/rest-service/), but when I try to use gradle build, I got this error :

My gradle problem

It doesnt work for this gradle, but when I use another one (that I took when I was at school) it work perfectly.

Do you actually have a main method (in the guide it's in the `Application`class)? — Dave Syer, Mar 20 '14 at 09:09
I have one in /main/java/hello/Application.class :package main.java.hello; public class Application { public static void main() { System.out.println("Test"); } } — mfrachet, Mar 20 '14 at 11:50
Is that "/main/java" or "./src/main/java"? Maybe you could put your code on github or something? — Dave Syer, Mar 20 '14 at 13:16

score 33 · Answer 1 · edited Oct 01 '19 at 12:49

33

There are two possibilities

Your source directory is not in the right location (use the sourceSets directive to fix this. your source directory should resemble something like src/main/java/your/package)

Add this to indicate where your main class is

springBoot {
     mainClass = "hello.FileUploader"
}

I am pretty sure it is 1.

edited Oct 01 '19 at 12:49

roottraveller

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answered Jun 19 '14 at 20:05

Pradeep

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For me, it was 2. :) Once I decided to plug in Spring Boot, I didn't realise I needed to config the main class. Still getting my way around both Gradle and Spring Boot... – Igor Donin Nov 29 '15 at 02:39
For me it was number 1: I didn't have `java` in my path -- I had `src/main/my/package` instead of `src/main/java/my/package` – Ryan Heathcote Feb 16 '16 at 20:01
I'm joint compiling Java and Groovy with `build.gradle` configured like in this answer: https://stackoverflow.com/a/22164339/185034, in other words I moved the `sourceSets`. #2 worked for me. – Paul Dec 06 '17 at 17:34

score 23 · Answer 2 · answered Feb 07 '17 at 06:46

23

I also have this problem, Here I solved the problem:

use org.springframework.boot:spring-boot-starter instead of org.springframework.boot:spring-boot-starter-web, if your project is only an module that will be used in other project.

Or Set the main class in gradle:

mainClassName = 'your.package.MainClass'

Or Just disable the bootRepackage

bootRepackage {
    enabled = false
}

answered Feb 07 '17 at 06:46

Bruce

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I just disabled repackage because it is just shared project in my case – gstackoverflow Oct 31 '17 at 18:54

score 7 · Answer 3 · answered Mar 21 '14 at 14:15

7

There is no main method in your project (otherwise the plugin would find one). A main method has a very specific signature, so check that you have public static void main(String[] args).

answered Mar 21 '14 at 14:15

Dave Syer

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This is not true, I am having the same problem and there is a public static void main(String[] args) in my project. – black sensei Oct 18 '14 at 10:52

score 6 · Answer 4 · answered Jan 21 '15 at 09:06

If the main class is not defined in the current project which the build.gradle file belongs to, but you want to launch it for some purpose, like sprint integration test. Do it like this:

Adding

bootRepackage {
    mainClass = 'your.app.package.Application'
}

in build.gradle (after the line apply plugin: 'spring-boot', because the plugin needs to be loaded) fix the problem.

score 2 · Answer 5 · answered Jun 29 '15 at 02:40

I know this is a very old post. But I came across this issue while trying to build my first spring- boot application (https://spring.io/guides/gs/spring-boot/#scratch). So the location of the pom.xml, mentioned in the tutorial is incorrect. You need to place it outside your src folder. So here is the final directory structure - /workspace/src/main/java/hello/HelloController.java /workspace/src/main/java/hello/Application.java /workspace/pom.xml

score 1 · Answer 6 · edited Jun 05 '16 at 11:36

1

I solved it by specifying the encoding. Probably it's because I wrote the code in an IDE.

java -Dfile.encoding=UTF-8 -jar build <filename>.jar

edited Jun 05 '16 at 11:36

coyotte508

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answered Jun 05 '16 at 11:12

surga

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score 1 · Answer 7 · edited Apr 28 '17 at 10:07

This happened to me as well.

I was confused by the location of build.gradle file: I thought it should be located in src/main/java/hello, because it is mentioned right after the instruction to create this sub-directory structure.

It should be placed in the root folder containing src folder. Once I did that and called "gradle build" from the root folder and not "./gradlew build" as the guide instructs, build was successful.

I did not perform the standard installation for gradle, just downloaded the binaries, maybe this is the reason that "./gradlew build" failed for me.

Unable to find main class :bootRepackage

7 Answers7

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