AOP, Hibernate, JDBC Interview Question

20. What is Spring AOP and proxy pattern?

Aspect-oriented programming (AOP) is a design pattern that helps us manage aspects like logging, security, and transaction management in applications. Spring AOP provides an implementation of AOP using dynamic proxies.

The proxy pattern is a software design pattern that creates a proxy object that intercepts incoming requests and controls access to another object before reaching the bean. In Spring AOP, dynamic proxies are used to implement aspects.

21. Explain key components of AOP.

• Aspect: A building block bundles together cross-cutting concerns. It has two main parts i.e. advice and pointcut.
  • Advice: The code that is executed before, after, or around a method invocation.
  • Pointcut: Condition triggering the tasks(advice).
• Join point: A specific point in the program execution where an aspect can be applied. Common join points are
  • method calls
  • field access
  • object creation
• Weaving: Spring supports weaving at compile, load, and runtime for integrating aspects in the application at join points.

23. Differentiate between Spring AOP and AspectJ AOP?

24. What are the advantages of AOP and its implementation?

AOP helps to maintain, modify, and understand code easily,

• Modularization: separation of concerns like logging, security, etc from core business logic, to increase maintainability.
• Reusability: Bundles concerns in reusable aspects, improving code reusability.
• Interception: Allows interception and modification of method calls, enabling features like logging, security, and caching.

25. Explain Hibernate ORM and ways to access it in Spring.

• Hibernate ORM: Hibernate is an object-relational mapping (ORM) framework, that provides a bridge between Java objects and relational database tables. Overall no need to write SQL queries manually. Hibernate works by
  • Persistence Context
  • Mapping
  • Session factory
  • Session
• Access in Spring: Spring provides several ways to integrate with Hibernate:
  • HibernateTemplate (legacy): Less preferred choice, It facilitates simpler data access through methods like get, load, and save.
  • Spring Data JPA: Recommended way, It simplifies data access using JPA annotations.
  • Direct JDBC Template: preferred choice for advanced scenarios, provides more control over data access.

26. Explain Hibernate Validator Framework and HibernateTemplate class?

• Hibernate Validator Framework: Provides validation against defined constraints, and prevents invalid data from entering the application. A few examples are listed-
  • @NotNull
  • @Size
  • @Email
• HibernateTemplate class: Provides an interface for data access operations like the one below, without writing SQL queries.
  • get
  • load
  • save
  • update
  • delete

27. Explain Spring JDBC API and its classes.

• Spring JDBC: Spring provides a simple way in the form of a JDBC abstraction layer to establish a bridge between database and application. It reduces boilerplate code and configurations.
• Key classes:
  • JdbcTemplate: Provides simple methods for executing SQL statements and working with data exchange for applications.
  • DataSource: Establish the connection(bridge) of data exchange from database.
  • SimpleJdbcCall: method present in Spring JDBC API, used for interacting with database-stored procedures.

28. What are the advantages of JdbcTemplate in Spring?

• Reduces boilerplate code: no need to write raw JDBC codes, also bundles common operations.
• Exception handling: auto handling and conversion of SQLExceptions into Spring’s DataAccessException.
• Prepared statements: Uses prepared statements to prevent SQL injection attacks.
• Data binding: instead of SQL statements it uses prepared statements, which have better-
  • Security – prevents SQL injection attacks
  • Performance – improved query performance

29. Fetching records using Spring JdbcTemplate?

Use the query method of JdbcTemplate with the appropriate SQL query and result extractor.

List<User> users = jdbcTemplate.query("SELECT * FROM users", new BeanPropertyRowMapper<>(User.class));

This code snippet fetches all users from the user’s table and maps them to User objects using the BeanPropertyRowMapper.

In this article, We will provide the Top Spring Java Interview Questions and Answers in 2024 tailored for both Freshers and Experienced Professionals with 2, 5, and 10 years of experience. Here, we cover everything, including Core Spring Java concepts, with subtle exploration into more advanced complex Topics.

Spring Framework is an open-source, lightweight, and easy-to-use framework that can be considered a framework of frameworks, which contains various frameworks, including the topics mentioned below.

Beginners: Spring fundamentals , Spring Dependency Injection, and Spring Bean
Experienced: AOP in Spring, Spring MVC, Spring JDBC , Spring Hibernate, Spring Web Service, EJB (Enterprise JavaBeans), and JSF (JavaServer Faces).

that will surely help you to Crack the Spring Java Interviews Question.