Init method in Spring Controller annotation version

Question

I m converting a controller to the newer annotation version  In the old version I used to specify the init method in springmvc-servlet xml using     lt beans gt       lt bean id  myBean  class       init-method  init   gt   lt  beans gt    How can I specify the init method using the annotation version

User · Accepted Answer

You can use   PostConstruct public void init

User · Answer

Alternatively you can have your class implement the InitializingBean interface to provide a callback function  afterPropertiesSet    which the ApplicationContext will invoke when the bean is constructed

User · Answer

public class InitHelloWorld implements BeanPostProcessor       public Object postProcessBeforeInitialization Object bean               String beanName  throws BeansException          System out println  BeforeInitialization       beanName          return bean      you can return any other object as well          public Object postProcessAfterInitialization Object bean               String beanName  throws BeansException          System out println  AfterInitialization       beanName          return bean      you can return any other object as well

User · Answer

There are several ways to intercept the initialization process in Spring  If you have to initialize all beans and autowire inject them there are at least two ways that I know of that will ensure this  I have only testet the second one but I belive both work the same    If you are using  Bean you can reference by initMethod  like this    Configuration public class BeanConfiguration       Bean initMethod  init     public BeanA beanA         return new BeanA           public class BeanA         method to be initialized after context is ready   public void init               If you are using  Component you can annotate with  EventListener like this    Component public class BeanB       EventListener   public void onApplicationEvent ContextRefreshedEvent event            In my case I have a legacy system where I am now taking use of IoC DI where Spring  Boot is the choosen framework  The old system brings many circular dependencies to the table and I therefore must use setter-dependency a lot  That gave me some headaches since I could not trust  PostConstruct since autowiring injection by setter was not yet done  The order is constructor   PostConstruct then autowired setters  I solved it with  EventListener annotation which wil run last and at the  same  time for all beans  The example shows implementation of InitializingBean aswell   I have two classes   Component  with dependency to each other  The classes looks the same for the purpose of this example displaying only one of them    Component public class BeanA implements InitializingBean     private BeanB beanB     public BeanA         log debug  Created               PostConstruct   private void postConstruct         log debug   PostConstruct            Autowired   public void setBeanB BeanB beanB        log debug   Autowired beanB        this beanB   beanB          Override   public void afterPropertiesSet   throws Exception       log debug  afterPropertiesSet              EventListener   public void onApplicationEvent ContextRefreshedEvent event        log debug   EventListener             This is the log output showing the order of the calls when the container starts   2018-11-30 18 29 30 504 DEBUG 3624 ---             main  com example demo BeanA                     Created    2018-11-30 18 29 30 509 DEBUG 3624 ---             main  com example demo BeanB                     Created    2018-11-30 18 29 30 517 DEBUG 3624 ---             main  com example demo BeanB                      Autowired beanA 2018-11-30 18 29 30 518 DEBUG 3624 ---             main  com example demo BeanB                      PostConstruct 2018-11-30 18 29 30 518 DEBUG 3624 ---             main  com example demo BeanB                     afterPropertiesSet   2018-11-30 18 29 30 518 DEBUG 3624 ---             main  com example demo BeanA                      Autowired beanB 2018-11-30 18 29 30 518 DEBUG 3624 ---             main  com example demo BeanA                      PostConstruct 2018-11-30 18 29 30 518 DEBUG 3624 ---             main  com example demo BeanA                     afterPropertiesSet   2018-11-30 18 29 30 607 DEBUG 3624 ---             main  com example demo BeanA                      EventListener 2018-11-30 18 29 30 607 DEBUG 3624 ---             main  com example demo BeanB                      EventListener   As you can see  EventListener is run last after everything is ready and configured

[java] Init method in Spring Controller (annotation version)

Examples related to java

Examples related to spring

Examples related to annotations

Examples related to controller