Infosys Java Developer Interview Questions and Answers

Spring Boot's default server is Tomcat, but you can easily switch to others like Jetty or Undertow.

• Spring Boot uses Tomcat as the default embedded server.

• To use Jetty, add the dependency: 'spring-boot-starter-jetty' in your pom.xml.

• For Undertow, include 'spring-boot-starter-undertow' in your dependencies.

• You can exclude Tomcat by adding 'exclude = {Tomcat.class}' in your @SpringBootApplication annotation.

Spring Boot's default port is 8080, and it can be changed via application properties or command line arguments.

• Default port: 8080.

• Change via application.properties: server.port=9090.

• Change via command line: java -jar app.jar --server.port=9090.

• Change via YAML: server: port: 9090

The Optional class is a container that may or may not hold a non-null value, helping to avoid NullPointerExceptions.

• Introduced in Java 8 to represent optional values.

• Helps in avoiding null checks and NullPointerExceptions.

• Methods include isPresent(), ifPresent(), orElse(), and orElseGet().

• Example: Optional<String> name = Optional.ofNullable(getName());

• Example: name.ifPresent(n -> System.out.println(n));

Optional.of() throws an exception for null, while Optional.ofNullable() allows null values, returning an empty Optional.

• Optional.of(T value): Requires a non-null value; throws NullPointerException if value is null.

• Example: Optional<String> opt = Optional.of('Hello'); // valid

• Optional.ofNullable(T value): Accepts null values; returns Optional.empty() if value is null.

• Example: Optional<String> opt = Optional....read more

To find the highest salary in a table, use the SQL MAX() function on the salary column.

• Use the SQL query: SELECT MAX(salary) FROM employees;

• Ensure the 'employees' table contains a 'salary' column.

• The MAX() function returns the maximum value from a specified column.

Receiving negative feedback is an opportunity for growth; I approach it with an open mind and a willingness to improve.

• Listen actively to the feedback without interrupting, showing respect for the manager's perspective.

• Ask clarifying questions to fully understand the feedback and the areas needing improvement.

• Reflect on the feedback and identify specific actions I can take to address the concerns raised.

• Create a plan t...read more

My short-term goal is to enhance my Java skills, while my long-term goal is to lead projects and mentor junior developers.

• Short-term: Master advanced Java frameworks like Spring and Hibernate to improve my development efficiency.

• Short-term: Contribute to open-source projects to gain real-world experience and collaborate with other developers.

• Long-term: Aim for a leadership role where I can guide teams in best practices...read more

Current company may have different priorities, budget constraints, existing systems, or may not see the immediate need for the technology.

• Different priorities: Company may be focusing on other projects or technologies that are deemed more important at the moment.

• Budget constraints: Implementing new technology can be costly and the company may not have the budget for it.

• Existing systems: Company may already have systems...read more

The company has chosen not to utilize XYZ technology due to budget constraints and compatibility issues.

• Budget constraints may have limited the company's ability to invest in new technologies.

• Compatibility issues with existing systems may have prevented the adoption of XYZ technology.

• The company may have determined that the benefits of XYZ technology do not outweigh the costs of implementation.

• There may be alternative ...read more