Java-Springs Interview Questions & Answers

Java-Springs Interview questions

Java-Springs Interview Questions

  1. Question1. What Is Spring?

    Answer :

    Spring is an open source framework created to address the complexity of enterprise application development. One of the chief advantages of the Spring framework is its layered architecture, which allows you to be selective about which of its components you use while also providing a cohesive framework for J2EE application development.

  2. Question2. What Are The Advantages Of Spring Framework?

    Answer :

    The advantages of Spring are as follows:
    ► Spring has layered architecture. Use what you need and leave you don't need now.
    ► Spring Enables POJO Programming. There is no behind the scene magic here. POJO programming enables continuous integration and testability.
    ► Dependency Injection and Inversion of Control Simplifies JDBC
    ► Open source and no vendor lock-in.

  3. Question3. What Are Features Of Spring?

    Answer :

    ► Lightweight:
    spring is lightweight when it comes to size and transparency. The basic version of spring framework is around 1MB. And the processing overhead is also very negligible.
    ► Inversion of control (IOC):
    Loose coupling is achieved in spring using the technique Inversion of Control. The objects give their dependencies instead of creating or looking for dependent objects.
    ► Aspect oriented (AOP):
    Spring supports Aspect oriented programming and enables cohesive development by separating application business logic from system services.
    ► Container:
    Spring contains and manages the life cycle and configuration of application objects.
    ► MVC Framework:
    Spring comes with MVC web application framework, built on core Spring functionality. This framework is highly configurable via strategy interfaces, and accommodates multiple view technologies like JSP, Velocity, Tiles, iText, and POI. But other frameworks can be easily used instead of Spring MVC Framework.
    ► Transaction Management:
    Spring framework provides a generic abstraction layer for transaction management. This allowing the developer to add the pluggable transaction managers, and making it easy to demarcate transactions without dealing with low-level issues. Spring's transaction support is not tied to J2EE environments and it can be also used in container less environments.
    ► JDBC Exception Handling:
    The JDBC abstraction layer of the Spring offers a meaningful exception hierarchy, which simplifies the error handling.

  4. Question4. How Many Modules Are There In Spring? What Are They?

    Answer :

    Spring comprises of seven modules. They are..
    ►The core container:
    The core container provides the essential functionality of the Spring framework. A primary component of the core container is the BeanFactory, an implementation of the Factory pattern. The BeanFactory applies the Inversion of Control (IOC) pattern to separate an application's configuration and dependency specification from the actual application code.
    ► Spring context:
    The Spring context is a configuration file that provides context information to the Spring framework. The Spring context includes enterprise services such as JNDI, EJB, e-mail, internalization, validation, and scheduling functionality.
    ► Spring AOP:
    The Spring AOP module integrates aspect-oriented programming functionality directly into the Spring framework, through its configuration management feature. As a result you can easily AOP-enable any object managed by the Spring framework. The Spring AOP module provides transaction management services for objects in any Spring-based application. With Spring AOP you can incorporate declarative transaction management into your applications without relying on EJB components.
    ►Spring DAO:
    The Spring JDBC DAO abstraction layer offers a meaningful exception hierarchy for managing the exception handling and error messages thrown by different database vendors. The exception hierarchy simplifies error handling and greatly reduces the amount of exception code you need to write, such as opening and closing connections. Spring DAO's JDBC-oriented exceptions comply to its generic DAO exception hierarchy.
    ►Spring ORM:
    The Spring framework plugs into several ORM frameworks to provide its Object Relational tool, including JDO, Hibernate, and iBatis SQL Maps. All of these comply to Spring's generic transaction and DAO exception hierarchies.
    ►Spring Web module:
    The Web context module builds on top of the application context module, providing contexts for Web-based applications. As a result, the Spring framework supports integration with Jakarta Struts. The Web module also eases the tasks of handling multi-part requests and binding request parameters to domain objects.
    ►Spring MVC framework:
    The Model-View-Controller (MVC) framework is a full-featured MVC implementation for building Web applications. The MVC framework is highly configurable via strategy interfaces and accommodates numerous view technologies including JSP, Velocity, Tiles, iText, and POI.

  5. Question5. What Are The Types Of Dependency Injection Spring Supports?

    Answer :

    ► Setter Injection:
    Setter-based DI is realized by calling setter methods on your beans after invoking a no-argument constructor or no-argument static factory method to instantiate your bean.

    ► Constructor Injection:
    Constructor-based DI is realized by invoking a constructor with a number of arguments, each representing a collaborator.

  6. Question6. What Is Bean Factory?

    Answer :

    A BeanFactory is like a factory class that contains a collection of beans. The BeanFactory holds Bean Definitions of multiple beans within itself and then instantiates the bean whenever asked for by clients.

    ► BeanFactory is able to create associations between collaborating objects as they are instantiated. This removes the burden of configuration from bean itself and the beans client.
    ► BeanFactory also takes part in the life cycle of a bean, making calls to custom initialization and destruction methods.

  7. Question7. What Is Application Context?

    Answer :

    A bean factory is fine to simple applications, but to take advantage of the full power of the Spring framework, you may want to move up to Springs more advanced container, the application context. On the surface, an application context is same as a bean factory.Both load bean definitions, wire beans together, and dispense beans upon request. But it also provides:

    ► A means for resolving text messages, including support for internationalization.
    ► A generic way to load file resources.
    ► Events to beans that are registered as listeners.

  8. Question8. What Is The Difference Between Bean Factory And Application Context?

    Answer :

    On the surface, an application context is same as a bean factory. But application context offers much more..
    ► Application contexts provide a means for resolving text messages, including support for i18n of those messages.
    ► Application contexts provide a generic way to load file resources, such as images.
    ► Application contexts can publish events to beans that are registered as listeners.
    ► Certain operations on the container or beans in the container, which have to be handled in a programmatic fashion with a bean factory, can be handled declaratively in an application context.
    ► ResourceLoader support: Springs Resource interface us a flexible generic abstraction for handling low-level resources. An application context itself is a ResourceLoader, Hence provides an application with access to deployment-specific Resource instances.
    ► MessageSource support: The application context implements MessageSource, an interface used to obtain localized messages, with the actual implementation being pluggable.

  9. Question9. How Is A Typical Spring Implementation Look Like?

    Answer :

    For a typical Spring Application we need the following files:
    ► An interface that defines the functions.
    ► An Implementation that contains properties, its setter and getter methods, functions etc.,
    ► Spring AOP (Aspect Oriented Programming)
    ► A XML file called Spring configuration file.
    ► Client program that uses the function.

  10. Question10. What Is The Typical Bean Life Cycle In Spring Bean Factory Container?

    Answer :

    Bean life cycle in Spring Bean Factory Container is as follows:
    ► The spring container finds the beans definition from the XML file and instantiates the bean.
    ► Using the dependency injection, spring populates all of the properties as specified in the bean definition
    ► If the bean implements the BeanNameAware interface, the factory calls setBeanName() passing the beans ID.
    ► If the bean implements the BeanFactoryAware interface, the factory calls setBeanFactory(), passing an instance of itself.
    ► If there are any BeanPostProcessors associated with the bean, their post- ProcessBeforeInitialization() methods will be called.
    ► If an init-method is specified for the bean, it will be called.
    ► Finally, if there are any BeanPostProcessors associated with the bean, their postProcessAfterInitialization() methods will be called.

  11. Question11. What Do You Mean By Bean Wiring?

    Answer :

    The act of creating associations between application components (beans) within the Spring container is reffered to as Bean wiring.

  12. Question12. What Do You Mean By Auto Wiring?

    Answer :

    The Spring container is able to autowire relationships between collaborating beans. This means that it is possible to automatically let Spring resolve collaborators (other beans) for your bean by inspecting the contents of the BeanFactory. The autowiring functionality has five modes.

    ► no
    ► byName
    ► byType
    ► constructor
    ► autodirect

  13. Question13. What Is Delegatingvariableresolver?

    Answer :

    Spring provides a custom JavaServer Faces VariableResolver implementation that extends the standard Java Server Faces managed beans mechanism which lets you use JSF and Spring together. This variable resolver is called as DelegatingVariableResolver

  14. Question14. What Is The Core Container Module?

    Answer :

    This module is provides the fundamental functionality of the spring framework. In this module BeanFactory is the heart of any spring-based application. The entire framework was built on the top of this module. This module makes the Spring container.

  15. Question15. What Is Application Context Module?

    Answer :

    The Application context module makes spring a framework. This module extends the concept of BeanFactory, providing support for internationalization (I18N) messages, application lifecycle events, and validation. This module also supplies many enterprise services such JNDI access, EJB integration, remoting, and scheduling. It also provides support to other framework.

  16. Question16. What Is Aop Module?

    Answer :

    The AOP module is used for developing aspects for our Spring-enabled application. Much of the support has been provided by the AOP Alliance in order to ensure the interoperability between Spring and other AOP frameworks. This module also introduces metadata programming to Spring. Using Springs metadata support, we will be able to add annotations to our source code that instruct Spring on where and how to apply aspects.

  17. Question17. What Is Jdbc Abstraction And Dao Module?

    Answer :

    Using this module we can keep up the database code clean and simple, and prevent problems that result from a failure to close database resources. A new layer of meaningful exceptions on top of the error messages given by several database servers is bought in this module. In addition, this module uses Springs AOP module to provide transaction management services for objects in a Spring application.

  18. Question18. What Are Object/relational Mapping Integration Module?

    Answer :

    Spring also supports for using of an object/relational mapping (ORM) tool over straight JDBC by providing the ORM module. Spring provide support to tie into several popular ORM frameworks, including Hibernate, JDO, and iBATIS SQL Maps. Springs transaction management supports each of these ORM frameworks as well as JDBC.

  19. Question19. What Is Web Module?

    Answer :

    This module is built on the application context module, providing a context that is appropriate for web-based applications. This module also contains support for several web-oriented tasks such as transparently handling multipart requests for file uploads and programmatic binding of request parameters to your business objects. It also contains integration support with Jakarta Struts.

  20. Question20. What Is Aop Alliance?

    Answer :

    AOP Alliance is an open-source project whose goal is to promote adoption of AOP and interoperability among different AOP implementations by defining a common set of interfaces and components.

Introduction To Spring Framework Dependency Injection And Inversion Of Control Modules Usage Scenarios New Features And Enhancements In Spring 3.0 Java 5 Improved Documentation New Module Organization And Build System Overview Of New Features The Ioc Container Introduction To The Spring Ioc Container And Beans Container Overview Bean Overview Dependencies Bean Scopes Customizing The Nature Of A Bean Bean Definition Inheritance Container Extension Points Annotation-based Container Configuration Classpath Scanning And Managed Components Java-based Container Configuration Registering A Loadtimeweaver Additional Capabilities Of The Applicationcontext The Beanfactory Resources The Resource Interface Built-in Resource Implementations The Resourceloader The Resourceloaderaware Interface Resources As Dependencies Application Contexts And Resource Paths Validation, Data Binding, And Type Conversion Validation Using Spring's Validator Interface Resolving Codes To Error Messages Bean Manipulation And The Beanwrapper Spring 3 Type Conversion Spring 3 Field Formatting Spring 3 Validation Spring Expression Language (spel) Feature Overview Expression Evaluation Using Spring's Expression Interface Expression Support For Defining Bean Definitions Language Reference Classes Used In The Examples Aspect Oriented Programming With Spring @aspectj Support Schema-based Aop Support Choosing Which Aop Declaration Style To Use Mixing Aspect Types Proxying Mechanisms Programmatic Creation Of @aspectj Proxies Using Aspectj With Spring Applications Spring Aop Apis Pointcut Api In Spring Advice Api In Spring Advisor Api In Spring Using The Proxyfactorybean To Create Aop Proxies Concise Proxy Definitions Creating Aop Proxies Programmatically With The Proxyfactory Manipulating Advised Objects Using The "autoproxy" Facility Using Targetsources Defining New Advice Types Testing Unit Testing Integration Testing Further Resources Transaction Management Introduction To Spring Framework Transaction Management Advantages Of The Spring Framework's Transaction Support Model Understanding The Spring Framework Transaction Abstraction Synchronizing Resources With Transactions Declarative Transaction Management Programmatic Transaction Management Choosing Between Programmatic And Declarative Transaction Management Application Server-specific Integration Solutions To Common Problems Dao Support Consistent Exception Hierarchy Annotations Used For Configuring Dao Or Repository Classes Data Access With Jdbc Introduction To Spring Framework Jdbc Using The Jdbc Core Classes To Control Basic Jdbc Processing And Error Handling Controlling Database Connections Jdbc Batch Operations Simplifying Jdbc Operations With The Simplejdbc Classes Modeling Jdbc Operations As Java Objects Common Problems With Parameter And Data Value Handling Embedded Database Support Initializing A Datasource Object Relational Mapping (orm) Data Access Introduction To Orm With Spring General Orm Integration Considerations Hibernate Jdo Jpa Ibatis Sql Maps Marshalling Xml Using O/x Mappers Marshaller And Unmarshaller Using Marshaller And Unmarshaller Xml Schema-based Configuration Jaxb Castor Xmlbeans Jibx Xstream Web Mvc Framework Introduction To Spring Web Mvc Framework The Dispatcherservlet Implementing Controllers Properties Of Handler Mappings Resolving Views Using Locales Using Themes Spring's Multipart (fileupload) Support Handling Exception Resolver Convention Over Configuration Support Etag Support Configuring Spring Mvc View Technologies View Technologies Introduction Jsp & Jstl Tiles Velocity & Freemarker Xslt Document Views (pdf/excel) Jasperreports Feed Views Xml Marshalling View Json Mapping View Integrating With Other Web Frameworks Integrating With Other Web Frameworks Introduction Common Configuration Javaserver Faces 1.1 And 1.2 Apache Struts 1.x And 2.x Webwork 2.x Tapestry 3.x And 4.x Injecting Spring-managed Beans Portlet Mvc Framework The Dispatcherportlet The Viewrendererservlet Controllers In Portlet Mvc Portlet Mode Handler Mappings Views And Resolving Them Multipart (file Upload) Support Handling Exceptions In Java Annotation-based Controller Configuration Portlet Application Deployment Remoting And Web Services Using Spring Remoting And Web Services Using Spring Introduction Exposing Services Using Rmi Using Hessian Or Burlap To Remotely Call Services Via Http Exposing Services Using Http Invokers Java Web Services Apis Jms Auto-detection Is Not Implemented For Remote Interfaces Considerations When Choosing A Technology Accessing Restful Services On The Client Enterprise Javabeans (ejb) Integration Accessing Ejbs Using Spring's Ejb Implementation Support Classes Jms (java Message Service) Java Message Service Introduction Using Spring Jms Sending A Message Receiving A Message Support For Jca Message Endpoints Jms Namespace Support Spring Jmx Jmx Introduction Exporting Your Beans To Jmx Controlling The Management Interface Of Your Beans Controlling The Objectnames For Your Beans Jsr-160 Connectors Accessing Mbeans Via Proxies Notifications Jca Cci Jca Cci Introductions Configuring Cci Using Spring's Cci Access Support Modeling Cci Access As Operation Objects Transactions Support Email Email Introduction Usage Using The Javamailsender And The Mimemessagepreparator Task Execution And Scheduling Task Execution And Scheduling Introduction The Spring Taskexecutor Abstraction The Spring Taskscheduler Abstraction The Task Namespace Annotation Support For Scheduling And Asynchronous Execution Using The Opensymphony Quartz Scheduler Using Jdk Timer Support Dynamic Language Support Dynamic Language Support Introduction A First Example Defining Beans That Are Backed By Dynamic Languages Scenarios Bits And Bobs Java-springs Interview Questions Java-springs Practice Tests