Juniper Networks Most Frequently Asked Spring MVC Latest Interview Questions Answers
What is Spring Security ?
Spring security is a project under spring framework umbrella, which provides support for security requirements of enterprise Java projects. Spring Security formerly known as aegis security provides out of box support for creating login screen, remember me cookie support, securing URL, authentication provider to authenticate the user from the database, LDAP and in memory, concurrent active session management support and much more. In order to use Spring security in a Spring MVC based project, you need to include spring-security.jar and configure it in application-Context-security.XML file, you can name it whatever you want, but make sure to supply this to ContextLoaderListener, which is responsible for creating Spring context and initializing dispatcher servlet.
How do you control concurrent Session on Java web application using Spring Security?
You can use Spring Security to control a number of active session in Java web application. Spring security framework provides this feature out of the box and when enabled , a user can only have one active session at a time.
What types of dependency injection is supported by Spring Framework? When do you use Setter and Constructor Injection, pros and cons?
There are 2 types of dependency injection supported by Spring, constructor based injection, and setter-based injection. Both types have their own advantages and disadvantages, you should use Constructor injection when object's dependencies are not optional and they must be initialized with their dependencies. Also use constructor injection if the order of initialization or dependency matters because in Setter based injection you cannot impose any order. Use setter injection when dependencies are optional.
How do Spring resolves view returned by ModelAndView class ?
Some Spring MVC questions are tricky e.g. Struts and Spring integration and can be only answered by experienced Java program with 2 to 4-year experience in Spring MVC framework.
What are different implementations of View interface you have used in Spring MVC?
ULBased View e.g. JSP , JSTLView,
How to escape HTML special characters using Spring MVC?
There are some methods in Spring tag library, can't remember now.
What does the ViewResolver class?
ViewResolver is an interface to be implemented by objects that can resolve views by name. There are plenty of ways using which you can resolve view names. These ways are supported by various in-built implementations of this interface. Most commonly used implementation is InternalResourceViewResolver class. It defines prefix and suffix properties to resolve the view component.
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
</bean>
So with above view resolver configuration, if controller method return “login” string, then the “/WEB-INF/views/login.jsp” file will be searched and rendered.
What is a MultipartResolver and when its used?
Spring comes with MultipartResolver to handle file upload in web application. There are two concrete implementations included in Spring:
CommonsMultipartResolver for Jakarta Commons FileUpload
StandardServletMultipartResolver for Servlet 3.0 Part API
To define an implementation, create a bean with the id “multipartResolver” in a DispatcherServlet’s application context. Such a resolver gets applied to all requests handled by that DispatcherServlet.
If a DispatcherServlet detects a multipart request, it will resolve it via the configured MultipartResolver and pass on a wrapped HttpServletRequest. Controllers can then cast their given request to the MultipartHttpServletRequest interface, which permits access to any MultipartFiles.
How does Spring MVC provide validation support?
Spring supports validations primarily into two ways.
Using JSR-303 Annotations and any reference implementation e.g. Hibernate Validator
Using custom implementation of org.springframework.validation.Validator interface.
What is Spring MVC Interceptor and how to use it?
As you know about servlet filters that they can pre-handle and post-handle every web request they serve — before and after it’s handled by that servlet. In the similar way, you can use HandlerInterceptor interface in your spring mvc application to pre-handle and post-handle web requests that are handled by Spring MVC controllers. These handlers are mostly used to manipulate the model attributes returned/submitted they are passed to the views/controllers.
A handler interceptor can be registered for particular URL mappings, so it only intercepts requests mapped to certain URLs. Each handler interceptor must implement the HandlerInterceptor interface, which contains three callback methods for you to implement: preHandle(), postHandle() and afterCompletion().
Problem with HandlerInterceptor interface is that your new class will have to implement all three methods irrespective of whether it is needed or not. To avoid overriding, you can use HandlerInterceptorAdapter class. This class implements HandlerInterceptor and provide default blank implementations.
What is Spring Security ?
Spring security is a project under spring framework umbrella, which provides support for security requirements of enterprise Java projects. Spring Security formerly known as aegis security provides out of box support for creating login screen, remember me cookie support, securing URL, authentication provider to authenticate the user from the database, LDAP and in memory, concurrent active session management support and much more. In order to use Spring security in a Spring MVC based project, you need to include spring-security.jar and configure it in application-Context-security.XML file, you can name it whatever you want, but make sure to supply this to ContextLoaderListener, which is responsible for creating Spring context and initializing dispatcher servlet.
How do you control concurrent Session on Java web application using Spring Security?
You can use Spring Security to control a number of active session in Java web application. Spring security framework provides this feature out of the box and when enabled , a user can only have one active session at a time.
What types of dependency injection is supported by Spring Framework? When do you use Setter and Constructor Injection, pros and cons?
There are 2 types of dependency injection supported by Spring, constructor based injection, and setter-based injection. Both types have their own advantages and disadvantages, you should use Constructor injection when object's dependencies are not optional and they must be initialized with their dependencies. Also use constructor injection if the order of initialization or dependency matters because in Setter based injection you cannot impose any order. Use setter injection when dependencies are optional.
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| Juniper Networks Most Frequently Asked Spring MVC Latest Interview Questions Answers |
How do Spring resolves view returned by ModelAndView class ?
Some Spring MVC questions are tricky e.g. Struts and Spring integration and can be only answered by experienced Java program with 2 to 4-year experience in Spring MVC framework.
What are different implementations of View interface you have used in Spring MVC?
ULBased View e.g. JSP , JSTLView,
How to escape HTML special characters using Spring MVC?
There are some methods in Spring tag library, can't remember now.
What does the ViewResolver class?
ViewResolver is an interface to be implemented by objects that can resolve views by name. There are plenty of ways using which you can resolve view names. These ways are supported by various in-built implementations of this interface. Most commonly used implementation is InternalResourceViewResolver class. It defines prefix and suffix properties to resolve the view component.
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
</bean>
So with above view resolver configuration, if controller method return “login” string, then the “/WEB-INF/views/login.jsp” file will be searched and rendered.
What is a MultipartResolver and when its used?
Spring comes with MultipartResolver to handle file upload in web application. There are two concrete implementations included in Spring:
CommonsMultipartResolver for Jakarta Commons FileUpload
StandardServletMultipartResolver for Servlet 3.0 Part API
To define an implementation, create a bean with the id “multipartResolver” in a DispatcherServlet’s application context. Such a resolver gets applied to all requests handled by that DispatcherServlet.
If a DispatcherServlet detects a multipart request, it will resolve it via the configured MultipartResolver and pass on a wrapped HttpServletRequest. Controllers can then cast their given request to the MultipartHttpServletRequest interface, which permits access to any MultipartFiles.
How does Spring MVC provide validation support?
Spring supports validations primarily into two ways.
Using JSR-303 Annotations and any reference implementation e.g. Hibernate Validator
Using custom implementation of org.springframework.validation.Validator interface.
What is Spring MVC Interceptor and how to use it?
As you know about servlet filters that they can pre-handle and post-handle every web request they serve — before and after it’s handled by that servlet. In the similar way, you can use HandlerInterceptor interface in your spring mvc application to pre-handle and post-handle web requests that are handled by Spring MVC controllers. These handlers are mostly used to manipulate the model attributes returned/submitted they are passed to the views/controllers.
A handler interceptor can be registered for particular URL mappings, so it only intercepts requests mapped to certain URLs. Each handler interceptor must implement the HandlerInterceptor interface, which contains three callback methods for you to implement: preHandle(), postHandle() and afterCompletion().
Problem with HandlerInterceptor interface is that your new class will have to implement all three methods irrespective of whether it is needed or not. To avoid overriding, you can use HandlerInterceptorAdapter class. This class implements HandlerInterceptor and provide default blank implementations.