Spring Boot scanBasePackages unable to find beans from dependency

Question

I have following:

@SpringBootApplication(scanBasePackages = {"com.my.package","com.my.package.mylibrary"})
@EnableAsync
@EnableSwagger2
@ServletComponentScan
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class, DataSourceTransactionManagerAutoConfiguration.class,
        HibernateJpaAutoConfiguration.class})
public class MySpringBootApplication {....}

This application has package com.my.package, and it also has a library dependency containing spring beans I want to autowire in this application, and those beans are in package com.my.package.mylibrary inside library.

So I have put both for scanBasePackages. But Spring is not able to find beans from the library?

Edit:

From library, I have:

package com.my.package.mylibrary.repository;
....
public interface MyRepository extends JpaRepository<..., ....> {....}

In application, I have:

package com.my.package.controller;
....
@RestController
public class MyController {....}

MySpringBootApplication resides in com.my.package.

Error:

Exception in thread "main" java.lang.NoClassDefFoundError: com/my/package/mylibrary/repository/MyRepository
    at com.my.package.MySpringBootApplication.main(MySpringBootApplication.java:32)
Caused by: java.lang.ClassNotFoundException: com.my.package.mylibrary.repository.MyRepository
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:602)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)

I added @EnableJpaRepositories for repository package. Now I see error related to entity MyEntity which MyRepository is based upon.

"java.lang.TypeNotPresentException: Type com.my.package.mylibrary.domain.MyEntity not present

So I added @EntityScan for "com.my.package.mylibrary.domain", but that makes application stuck infinitely.

Let's show few classes in package `com.my.package`, `com.my.package.mylibrary`! — Vy Do, Jun 13 '20 at 03:28
The @SpringBootApplication annotation is equivalent to using Configuration, EnableAutoConfiguration and ComponentScan with their default attributes: [...]. If specific packages are not defined, scanning will occur from the package of the class that declares this annotation. — AchillesVan, Jun 13 '20 at 04:47
read this https://stackoverflow.com/questions/33619532/configuration-using-annotation-springbootapplication — AchillesVan, Jun 13 '20 at 04:53
It will automatically pick you don't need to add scanPackages. — Anish B., Jun 13 '20 at 07:20

Anish B. · Accepted Answer · 2020-06-13T07:55:52.253

3

First of all, you don't need to add scanBasePackages attribute in @SpringBootApplication as the base package is com.my.package.

If package is totally different, then you could have added it.

Spring Boot will automatically pick up the bean if the base package is same.

There is something called as separation of concerns that you should follow when you are writing code.

Update your MySpringBootApplication class to this :

@SpringBootApplication
@ServletComponentScan
public class MySpringBootApplication {....}

Create a separate config for asynchronous method execution.

 @Configuration
 @EnableAsync
 public class AsynchronousConfig {.....}

Create a separate config class for Swagger 2.

@Configuration
@EnableSwagger2
public class SwaggerConfiguration {....}

Create separate config to exclude configuration.

@Configuration
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class, 
DataSourceTransactionManagerAutoConfiguration.class,
HibernateJpaAutoConfiguration.class})
public class ExcludeConfigurationFile {....}

Note: Spring boot auto configuration will automatically pick up these @Configuration files

This should work.

edited Jun 13 '20 at 07:55

answered Jun 13 '20 at 07:22

Anish B.

9,111
3
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1

I have removed ServletComponentScan. EntityScan and EnableJpaRepositories. I still see java.lang.TypeNotPresentException: Type com.my.package.mylibrary.domain.MyEntity not present. Somehow spring is not able to load entity class. – Mandroid Jun 13 '20 at 07:49
@Mandroid Do you have this entity com.my.package.mylibrary.domain.MyEntity ? – Anish B. Jun 13 '20 at 07:50
1

Yes. MyRepository is defined for it. – Mandroid Jun 13 '20 at 07:52
@Mandroid Add the code of com.my.package.mylibrary.domain.MyEntity ? – Anish B. Jun 13 '20 at 07:52
@Mandroid Check whether MyEntity class exists or not ? – Anish B. Jun 13 '20 at 07:54

score 0 · Answer 2 · answered Jun 13 '20 at 09:59

You might want to scan the packages seperately and change your JpaRepository to CrudRepository. The configuration to seperate the layer is as follow.

@SpringBootApplication(scanBasePackages = {"com.my.package.controller"})
@EnableJpaRepositories(basePackages = {"com.my.package.mylibrary.repository"})
@EntityScan(basePackages = {"com.my.package.mylibrary.domain"})
public class MySpringBootApplication {

    public static void main(String[] args) {
        MySpringBootApplication.run(MySpringBootApplication.class, args);
    }
}

Spring Boot scanBasePackages unable to find beans from dependency

2 Answers2