A Java programmer must know the answers to a few of the popular Spring questions before appearing for the interview. There are some popular interview questions for any level Java Programmer. For web applications Spring Framework is one of the popular Java EE frameworks. Two most popular concepts of Java programming are Aspect Oriented Programming and Dependency Injection. Let’s see mostly asked interview questions for freshers.
Before appearing for an interview if you will know the answers to these questions, then it will be good. While reading these spring MVC interview questions for experienced and freshers you will surely like them and will not like to miss them et al. Few are those interesting questions.
With the two core concepts of Aspect-Oriented and Dependency Injection, Spring is one of the most popular and widely used Java EE frameworks. Through dependency injection it can provide tight coupling between various components. The cross-cutting tasks such as authentication and logging can be provided through Spring framework and the aspect-oriented programming can be implemented through this as well.
Spring framework is a featured framework which can provide several modules and lots of features for the specific tasks such as Spring JDBC and Spring MVC. Working with Spring is quite easy and a fun activity due to the presence of a number of online communities and resources.
Spring framework is based on two main concepts known as aspect-oriented programming and dependency injection. Few features of Spring framework are:
Dependency injection is a concept which is implemented through the design patterns. It can remove the hard-coded dependency and can make the application loosely coupled, maintainable and extendable. The dependency resolution can also be moved from compile time to run time through these design patterns. It provides following benefits:
Google Guice can also be used for dependency injection and the processes can be automated through this. If we want to implement any additional concept along with dependency injection then Spring is the best choice for that.
Spring framework offers a number of advantages which includes the following:
Some important and mostly used Spring modules are:
Q6). Explain Aspect Oriented Programming.
Some cross-cutting concerns for any enterprise level application like transaction management, data validation, authentication and logging in for various application modules and objects are most valuable. In case of object-oriented programming such application modularity is implemented by classes while in AOP it is achieved by Aspects.
The industry standard implementation of Aspect-oriented programming is called AspectJ while implementation of AOP can also be done with the help of Springs. The major difference between AspectJ and Spring AOP are listed below:
Any class of Spring framework, which is initialized by Spring IoC container is known as Spring Bean. We can get the Spring Bean instance through Spring Application Context. The life-cycle of Spring Bean can be managed by Spring IoC container.
Following five are the main scopes of Spring Beans:
The Spring framework is extendable user can also create his own scope as well. While the Spring defined scope is also used by the developers. The “scope” attribute of the bean element is used to define its scope.
The above-listed ones are mostly asked for spring MVC interview questions and answers. Apart from these there can be other spring MVC interview questions as well. You can find other questions to clear the interview.
spring MVC Interview Questions & Answers for Experienced Candidates
Q10). Define Spring Bean.
When a normal java class starts with IoC container it is called Spring Bean. To get the Spring Bean instance we can use Spring Application Context. The life cycle of Spring Bean is managed by IoC container, it also manages the scope of bean and the dependencies required in case of bean injection in any module.
All beans that are initialized by Spring Context are defined in Spring Bean configuration file. When an instance of Spring Application Context is created it reads spring bean XML file and initializes all of them. The context is initialized once in the bean life cycle and then it can be used to get different bean instances throughout its lifecycle.
This file not only contains Spring Bean configuration instead it also contains Spring MVC view resolvers, interceptors and other annotations which can support other configuration based elements.
We can configure any java class to Spring Bean by following three ways:
XML configuration is the most popular one and the bean element can be used in the contextfile to configure a Spring Bean. The example is given below:
Java Based Configuration :
The beans can also be configured by using @Bean annotations. It is used with @Configuration classes through which you can configure the bean. An example is given below:
Annotation Based Configuration:
We can use @Service, @Component, @Controller and @Repository annotations with the normal java classes if we want to configure them as a Bean. To provide such annotation the base package class location has to be specified for these classes. An example is given below:
The complete process of injecting a bean dependency at the time of its initialization is known as Spring Bean wiring. Though the user can do theexplicit wiring for all the beans in spring framework you can also use autowiring. For this the annotation @Autowired can be used with filesautowiring byType. For this we will also have to enable annotation-based configuration located in the Spring bean file
In Spring framework following four types of autowiring is defined:
Default scope of any bean in the Spring framework is asingleton, so only one instance per context can be there. Therefore the class level variables which can be updated through thread may lead to inconsistent data so Spring beans are not threaded safe. To achieve thread safety the bean scope can be changed to prototype, request or session and for that the performance may have to be compromised.
Like MVC design patterns Spring Bean Controller class take care of the requests coming from any client and it sends them to the configured resources which can handle it. The front controller class org.springframework.web.servlet.DispatcherServlet initializes the contexts on the basis of spring bean configurations.
A Controller class can handle various kind of client requests on the basis of request mapping. By using @Controller annotation the controller class can be created.
This blog covers the questions which you can read and solve if you want to crack the interview for Spring bean professional. Java professionals also have to get practical knowledge along with theoretical concepts. The questions are covered for both fresher and experienced professionals and you can also find many others questions if you want to be a proficient Java developer and want to crack Spring interview.
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