Unable to autowire dozer Mapper in component class in spring boot

Question

I am new to Spring Boot. I was trying to develop small application in spring boot mvc with neo4j database. Following is my Server

@Configuration
@ComponentScan({ "myproject" })
@EnableAutoConfiguration
@EnableNeo4jRepositories(basePackages = "myproject")
public class Server extends Neo4jConfiguration implements CommandLineRunner
{

public Server()
{
    setBasePackage("myproject");
}

@Bean
SpringRestGraphDatabase graphDatabaseService()
{
    return new SpringRestGraphDatabase("http://localhost:7474/db/data");
}

@Bean
Mapper mapper()
{
    return new DozerBeanMapper();
}

public void run(String... args) throws Exception
{
}

public static void main(String[] args) throws Exception
{
    SpringApplication.run(Server.class, args);
}

}

Following is my main class

@Configuration
@ComponentScan({ "myproject.business" })
@EnableNeo4jRepositories(basePackages = "myproject")
public class MainWithStructure extends Neo4jConfiguration implements CommandLineRunner
{
@Autowired
private MyService myService;

public MainWithStructure()
{
    setBasePackage("myproject");
}

@Bean
SpringRestGraphDatabase graphDatabaseService()
{
    return new SpringRestGraphDatabase("http://localhost:7474/db/data");
}

.......
......
public static void main(String[] args) throws Exception
{
    FileUtils.deleteRecursively(new File("accessingdataneo4j.db"));

    SpringApplication app = new SpringApplication(MainWithStructure.class);
    app.setWebEnvironment(false);
    app.run(args);
}

}

Following is my Component class

@Component
public class MyService
{

@Autowired
private Mapper mapper;  //Fails to autowire org.dozer.Mapper

.....
}

Following is my Controller class

@RestController
@RequestMapping("/rest")
public class MyController
{
@Autowired
private Mapper mapper;  //autowire sucess org.dozer.Mapper
}

I got following Exception when I run main class MainWithStructure

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mainWithStructure': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private myproject.business.MyService myproject.main.MainWithStructure.MyService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'myService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.dozer.Mapper myproject.business.MyService.mapper; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.dozer.Mapper] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

Following is my project structure

demo_project

src/main/java

---myproject.main

------MainWithStructure.java

------Server.java

---myproject.business

------MyService.java

---myproject.rest

------MyController.java

If I autowire org.dozer.Mapper in Controller, it sucessfuly autowired it. BUT if I autowire org.dozer.Mapper in Component class it fails to autowire. Why it is failing to autowire org.dozer.Mapper only on Component class?

Please make me correct if I wrong. Thank you :)

How exactly does it fail? Is Spring trying and failing to create an instance of MyService, or not trying to create one at all? Can you update the question with the error? Also, what packages are you various classes in? They'll all need to be in a package called myproject or a sub-package of it. — Andy Wilkinson
Got it from one of your past post answer ;). Just wrote @ComponentScan instead of @ComponentScan({ "myproject.business" }) on MainWithStructire class — Prashant Shilimkar

Dave Syer Dave Syer · Accepted Answer · 2014-09-18T09:48:05

Your Server is not in one of the packages that you @ComponentScan, so the Mapper is indeed not a bean. Try removing the explicit package from the @ComponentScan (since everything is in a subpackage of the main class that will pick up all the components).

Unable to autowire dozer Mapper in component class in spring boot

2 Answers