Capgemini Senior Java Developer Interview Questions, Process, and Tips

Interview questions for Senior Java Developer

• List is an ordered collection, Set is an unordered collection with no duplicates, Map is a key-value pair collection

• Exception handling is used to handle runtime errors and prevent program crashes

• Throw is used to throw an exception explicitly, Throws is used to declare an exception that a method may throw

• Threads are used to execute multiple tasks simultaneously and improve pr...read more

Program using Java 8 features to filter a list of strings starting with 'A' and convert them to uppercase.

• Use Java 8 stream API to filter the strings starting with 'A'.

• Use map() function to convert the filtered strings to uppercase.

• Collect the results into a new list using collect() function.

To connect two databases in Spring Boot, you can configure multiple data sources and use JPA to interact with them.

• Configure multiple data sources in application.properties or application.yml file

• Define multiple DataSource beans in your configuration class

• Use @Primary annotation to specify the primary data source

• Use @Qualifier annotation to specify which data source to use in a specific repository or service

• Use @Transa...read more

An index in MySQL is a data structure that improves the speed of data retrieval operations on a database table.

• Indexes are used to quickly locate rows in a table without having to search every row.

• They can be created on one or more columns in a table.

• Indexes can be unique, which means that the indexed columns must contain unique values.

• Examples of indexes include primary keys, unique keys, and regular indexes.

Post mapping is used to create or update data, while get mapping is used to retrieve data. Yes, data can be updated using post mapping.

• Post mapping is used to create or update data in the server, while get mapping is used to retrieve data from the server.

• Post mapping is typically used for operations that modify data, such as creating a new resource or updating an existing one.

• Get mapping is used for operations that do ...read more

Design patterns in microservices architecture help in solving common problems and improving scalability, maintainability, and flexibility.

• Service Registry pattern - used for service discovery and registration, such as Netflix Eureka

• Circuit Breaker pattern - prevents cascading failures by failing fast and providing fallback mechanisms, like Hystrix

• API Gateway pattern - acts as a single entry point for clients to access ...read more

SOLID principles are a set of five design principles in object-oriented programming to make software designs more understandable, flexible, and maintainable.

• S - Single Responsibility Principle: A class should have only one reason to change.

• O - Open/Closed Principle: Classes should be open for extension but closed for modification.

• L - Liskov Substitution Principle: Objects of a superclass should be replaceable with obje...read more

Spring Boot simplifies the development of Spring applications by providing out-of-the-box configurations and reducing boilerplate code.

• Spring Boot provides a quick and easy way to set up a Spring application with minimal configuration.

• It includes embedded servers like Tomcat, Jetty, or Undertow, eliminating the need for deploying WAR files.

• Auto-configuration feature in Spring Boot automatically configures the applicati...read more