org springframework beans factory UnsatisfiedDependencyException Error creating bean with name demoRestController

Question

I am new to Spring and I am trying to make an application for learning but I am getting problems with Autowiring.I am adding my code. I am working on spring boots.

Spring Boot Code

public class DemoApplication { 

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

LoginBean.java

@Service 
@Component 
public class LoginBean { 
        private String userId; 
        private String pwd; 

        public String getUserId() { 
                return userId; 
} 

public void setUserId(String userId) { 
        this.userId = userId; 
} 

public String getPwd() { 
        return pwd; } 

public void setPwd(String pwd) { 
        this.pwd = pwd; 
}

DemoRestController.java

@RestController 
@EnableAutoConfiguration 
@RequestMapping("/demo") 
@Component 
public class DemoRestController { 


              private final LoginBean loginBean; 

              @Autowired 
              public DemoRestController(LoginBean loginBean) { 
                      this.loginBean=loginBean; 
} 

            @RequestMapping(value = "/login/{id},{pwd}", method = RequestMethod.GET, produces = "application/json") 
              public @ResponseBody LoginBean loginService(@PathVariable String id, @PathVariable String pwd) { 

            //LoginBean loginBean = new LoginBean(); 

              loginBean.setUserId(id); 
              loginBean.setPwd(pwd); 
              return loginBean; 
}

I tried @Autowired to LoginBean loginBean, created getter setter of LoginBean in Controller class and autowired setters along with creating the constructor of Controller and autowired, as given in above code;

Below is the error which I am getting

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'demoRestController': Unsatisfied dependency expressed through constructor argument with index 0 of type [com.ag.digital.demo.bean.LoginBean]: No qualifying bean of type [com.ag.digital.demo.bean.LoginBean] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.ag.digital.demo.bean.LoginBean] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {} 
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:185) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839) ~[spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE] 
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE] 
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE] 
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE] 
at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE] 
at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE] 
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1191) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE] 
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1180) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE] 
at com.ag.digital.demo.boot.DemoApplication.main(DemoApplication.java:14) [classes/:na] Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.ag.digital.demo.bean.LoginBean] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {} 
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1373) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1119) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1014) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:813) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] 
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE] ... 19 common frames omitted

Aditya · Answer 1 · Feb 23, 2022

To answer your doubt, the DemoApplication class is in the comag.digital.demo.boot package and your LoginBean class is in the com.ag.digital.demo.bean package. By default components are found if they are in the same package or a sub-package of your main application class DemoApplication. This means that LoginBean isn't being found so dependency injection fails.

To solve your problem, you need to Move LoginBean into com.ag.digital.demo.boot or a sub-package and then configure the packages that are scanned for components using the scanBasePackages attribute of @SpringBootApplication that should be on DemoApplication.