Could not autowire field in spring why

Question

I keep getting this error  and can t figure out why   yes I know there many people had similar issues  but reading the answers they got  does not solve my problem      org springframework beans factory BeanCreationException  Error creating bean with name  contactController   Injection of autowired dependencies failed  nested exception is org springframework beans factory BeanCreationException  Could not autowire field  private net service ContactService net controller ContactController contactService  nested exception is org springframework beans factory NoSuchBeanDefinitionException  No matching bean of type  net service ContactService  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     here is the controller    Controller  SessionAttributes public class ContactController         Autowired     private ContactService contactService    methods          the ContactServiceImpl   Service  contactService    Transactional propagation   Propagation SUPPORTS  readOnly   true  public class ContactServiceImpl implements ContactService         Autowired     private ContactDao contactDao       public ContactServiceImpl                 Override      Transactional propagation   Propagation REQUIRED  readOnly   false      public void addContact Contact contact            contactDao saveContact contact               Override     public List lt Contact gt  getContacts             return contactDao getAllContacts               the ContactDaoImpl   Repository  contactDao   public class ContactDaoImpl implements ContactDao         Autowired     private SessionFactory sessionFactory        Override     public void saveContact Contact contact            sessionFactory getCurrentSession   saveOrUpdate contact               Override      SuppressWarnings  unchecked       public List lt Contact gt  getAllContacts             return  List lt Contact gt   sessionFactory getCurrentSession   createQuery  from contact c   list               and the spring-servlet xml   lt  xml version  1 0  encoding  UTF-8   gt   lt beans xmlns  http   www springframework org schema beans      xmlns xsi  http   www w3 org 2001 XMLSchema-instance  xmlns context  http   www springframework org schema context      xmlns tx  http   www springframework org schema tx      xsi schemaLocation   http   www springframework org schema beans http   www springframework org schema beans spring-beans-3 0 xsd http   www springframework org schema context http   www springframework org schema context spring-context-3 0 xsd http   www springframework org schema tx http   www springframework org schema tx spring-tx-3 0 xsd  gt        lt context property-placeholder location  classpath jdbc properties    gt       lt context component-scan base-package  net controller    gt         lt tx annotation-driven transaction-manager  hibernateTransactionManager    gt        lt bean id  viewResolver          class  org springframework web servlet view UrlBasedViewResolver  gt           lt property name  viewClass              value  org springframework web servlet view JstlView    gt           lt property name  prefix  value   WEB-INF jsp     gt           lt property name  suffix  value   jsp    gt       lt  bean gt        lt bean id  dataSource          class  org springframework jdbc datasource DriverManagerDataSource  gt           lt property name  driverClassName  value    database driver     gt           lt property name  url  value    database url     gt           lt property name  username  value    database user     gt           lt property name  password  value    database password     gt       lt  bean gt        lt bean id  sessionFactory          class  org springframework orm hibernate3 annotation AnnotationSessionFactoryBean  gt           lt property name  dataSource  ref  dataSource    gt           lt property name  annotatedClasses  gt               lt list gt                   lt value gt net form Contact lt  value gt               lt  list gt           lt  property gt             lt property name  hibernateProperties  gt               lt props gt                   lt prop key  hibernate dialect  gt   hibernate dialect  lt  prop gt                   lt prop key  hibernate show sql  gt   hibernate show sql  lt  prop gt               lt  props gt           lt  property gt       lt  bean gt        lt bean id  hibernateTransactionManager          class  org springframework orm hibernate3 HibernateTransactionManager  gt           lt property name  sessionFactory  ref  sessionFactory    gt       lt  bean gt   lt  beans gt

User · Answer

I was getting this same error and searching for it led me here. My fix appeared to be simply to add @Component annotation to the implementation of the abstract service.

In this case, that would look like:

import org.springframework.stereotype.Component;

...

@Component
public class ContactServiceImpl implements ContactService {

User · Answer

Well there s a problem with the creation of the ContactServiceImpl bean  First  make sure that the class is actually instantiated by debugging the no-args constructor when the Spring context is initiated and when an instance of ContactController is created   If the ContactServiceImpl is actually instantiated by the Spring context  but it s simply not matched against your  Autowire annotation  try being more explicit in your annotation injection  Here s a guy dealing with a similar problem as yours and giving some possible solutions   http   blogs sourceallies com 2011 08 spring-injection-with-resource-and-autowired   If you ask me  I think you ll be ok if you replace    Autowired private ContactService contactService    with    Resource  Qualifier  contactService   private ContactService contactService

User · Answer

I had exactly the same problem try to put the two classes in the same package and add line in the pom xml    lt dependency gt                lt groupId gt  org springframework boot  lt  groupId gt                lt artifactId gt  spring-boot-starter-web  lt  artifactId gt                lt version gt  1 2 0 RELEASE  lt  version gt    lt  dependency gt

User · Answer

In spring servlet  xml     lt context component-scan base-package  net controller    gt     I assumed that the service impl is in the same package as the service interface  net service    I think you have to add the package net service  or all of net  to the component scan  Currently spring only searches in net controller for components and as your service impl is in net service  it will not be instantiated by spring

User · Answer

When you get this error some annotation is missing  I was missing  service annotation on service  When I added that annotation it worked fine for me

User · Answer

In java config make sure you have import your config in RootConfig like this      Import PersistenceJPAConfig class

User · Answer

I ve faced the same issue today  Turned out to be I forgot to mention  Service  Component annotation for my service implementation file  for which spring is not able autowire and failing to create the bean

[java] Could not autowire field in spring. why?

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