While working with Hibernate you might have encountered the following error- org.hibernate.LazyInitializationException could not initialize proxy – no Session In this tutorial we’ll see why this error comes up and what is the best way to fix it. Why LazyInitializationException : could not initialize proxy You may encounter this error…
In this post we’ll see where and how to use @PostConstruct and @PreDestroy annotations with in the Spring bean life cycle. Spring @PostConstruct annotation The PostConstruct annotation is used on a method that needs to be executed after dependency injection is done to perform any initialization. Any method annotated with…
Spring container not only instantiates a bean and wire its dependencies it also provides the scope of an instance. There is inbuilt support for six bean scopes in Spring Framework. For example, bean scope can be singleton, prototype and so forth. This post shows how to set a bean scope…
Rather than providing bean definitions and the dependencies in the Spring XML Configuration you can make the Spring framework itself automatically detect the classes by scanning the classpath and register the corresponding bean definition with the container. That can be done using Spring @Component annotation which is a generic annotation…
Spring framework can automatically detect the classes annotated with @Component and other stereotype annotations like @Repository, @Service, @Controller. You need some way to tell Spring where to look for classes annotated with one of these annotations. For that you can use Spring @ComponentScan annotation, you can also specify the base…
Sometimes dependencies between beans may not be direct but you may still want to ensure that a specific bean is initialized before another bean. For example in one bean there is a static block which has to be executed before another bean is initialized. You can use Spring @DependsOn annotation…
Spring @Autowired annotation is used to automatically inject dependencies. Where to apply @Autowired annotation You can apply the @Autowired annotation to setter methods. See example. You can apply the @Autowired annotation to constructors. See example. You can apply @Autowired to fields. See example. You can also apply the annotation to…
For autowiring in Spring apart from using @Autowired annotation there is also support for JSR 330’s @Inject annotation and JSR-250 @Resource annotation. In this post we’ll see how to use Spring @Resource annotation for autowiring. @Resource annotation in Spring @Resource annotation can be used on fields or bean property setter…
Spring @Configuration annotation helps in creating Java based configuration in Spring rather than relying on XML based configuration. Any class annotated with @Configuration indicates that a class declares one or more @Bean methods that are processed by the Spring container to generate bean definitions and manage the overall bean lifecycle.…
Spring @Required annotation is used with a method, typically a setter method thus making setter dependency injection for that property mandatory. RequiredAnnotationBeanPostProcessor class Registering RequiredAnnotationBeanPostProcessor class is required to use @Required annotation. A default RequiredAnnotationBeanPostProcessor will be registered by the “context:annotation-config” and “context:component-scan” XML tags. Spring @Required annotation examples In…
