Spring Interview Questions
Spring Interview Questions
Spring Interview Questions for Fresher
What is Spring ?
It is a lightweight, loosely coupled and integrated framework for developing enterprise applications in java.
What are the advantages of spring framework ?
Spring framework have following advantage;.
- Predefined Templates
- Loose Coupling
- Easy to test
- Lightweight
- Fast Development
- Powerful Abstraction
- Declarative support
What are the modules of spring framework ?
Modules of spring framework are given below.
- Test
- Spring Core Container
- AOP, Aspects and Instrumentation
- Data Access/Integration
- Web
What is IOC and DI ?
IOC (Inversion of Control) and DI (Dependency Injection) is a design pattern to provide loose coupling. It removes the dependency from the program.
Let's write a code without following IOC and DI.
Example
public class Employee
{
Address address;
Employee()
{
address=new Address(); //creating instance
}
}
Now, there is dependency between Employee and Address because Employee is forced to use the same address instance.
Let's write the IOC or DI code.
Example
public class Employee
{
Address address;
Employee(Address address)
{
this.address=address; //not creating instance
}
}
Now, there is no dependency between Employee and Address because Employee is not forced to use the same address instance. It can use any address instance.
What is the role of IOC container in spring ?
IOC container is responsible to:
- create the instance
- configure the instance, and
- assemble the dependencies
What are the types of IOC container in spring ?
There are two types of IOC containers in spring framework.
- BeanFactory
- ApplicationContext
What is the difference between BeanFactory and ApplicationContext ?
BeanFactory is the basic container whereas ApplicationContext is the advanced container. ApplicationContext extends the BeanFactory interface. ApplicationContext provides more facilities than BeanFactory such as integration with spring AOP, message resource handling for i18n etc.
Difference between constructor injection and setter injection
| Constructor Injection | Setter Injection |
|---|---|
| No Partial Injection | Partial Injection |
| Desn't override the setter property | Overrides the constructor property if both are defined. |
| Creates new instance if any modification occurs | Doesn't create new instance if you change the property value |
| Better for too many properties | Better for few properties. |
In which scenario, you will use singleton and prototype scope ?
Singleton scope should be used with EJB stateless session bean and prototype scope with EJB stateful session bean.
What are the transaction management supports provided by spring ?
Spring framework provides two type of transaction management supports:
- Programmatic Transaction Management: Should be used for few transaction operations.
- Declarative Transaction Management: Should be used for many transaction operations.
What is default scope of bean in Spring framework ?
The default scope of a Spring bean is Singleton scope, you can read this article which explains about all possible scope of a spring bean : What is bean scope in Spring.
Does Spring singleton beans are thread-safe ?
No, Spring singleton beans are not thread-safe. Singleton doesn't mean bean would be thread-safe.
What is dependency Injection ?
Dependency Injection is one of the design pattern, which allows injecting dependency on Object, instead of object resolving the dependency.
What are different implementations of View interface you have used in Spring MVC ?
ULBased View e.g. JSP , JSTLView.
Define Bean Wiring ?
Bean wiring is the creation of associations between application components that are between the beans in a particular spring container.
What is called Spring MVC ?
A Spring MVC is a single shared controller instance and it is used to handle request type controllers, interceptors which run in the IoC container. It also allows multiple Dispatcher Servlets which can share application context interface but not class based interface.
Why Spring framework is needed ?
Spring framework is needed because it is;
- Very Light Weight Container
- Framework
- IOC
- AOP
What is Auto Wiring ?
Autowiring is used to build relationships between the collaborating beans. Spring container can automatically resolve collaborators for beans.
Differentiate between singleton and prototype bean ?
Singleton means only one bean is defined per object instance while Prototype means one definition to more than one object instances in Spring.
Write about Core container module
Core container module is responsible for the basic functionality of the spring framework. The whole Spring framework is built with this module as a base.
What is a Pointcut ?
Pointcut is used to allow where the advice can be applied.
What is weaving ?
Weaving is used to create new proxy object by applying aspects to target object.
What is difference between singleton and prototype bean ?
Singleton Bean: Single bean definition to a single object instance per Spring IOC container
Prototype Bean :Single bean definition to any number of object instances per Spring IOC Container
What are the different types of AutoProxying ?
- BeanNameAutoProxyCreator
- DefaultAdvisorAutoProxyCreator
- Metadata autoproxying
How can beans be made singleton or prototype ?
The bean tag has an attribute called ‘singleton’. The bean is singleton if its value is ‘TRUE’, otherwise the bean is a prototype.