NTT Data Senior Java Developer Interview Questions, Process, and Tips

Interfaces allow multiple inheritance, abstract classes do not.

• Interfaces can be implemented by multiple classes, allowing for multiple inheritance.

• Abstract classes can only be extended by one class, limiting inheritance.

• Interfaces promote loose coupling and flexibility in design.

• Abstract classes provide a common base implementation for subclasses.

Program to find occurrences of a specified character in a string, excluding spaces and special symbols.

• Iterate through each character in the string

• Check if the character is the specified character and not a space or special symbol

• Store the occurrences in an array of strings

Autowired annotation in Spring framework injects dependencies automatically

• Autowired annotation is used for automatic dependency injection in Spring framework

• It eliminates the need for explicit bean wiring in XML configuration files

• Autowired annotation can be used on fields, constructors, or methods

• It searches for a bean of the same type and injects it into the annotated field

Spring Boot uses @Primary annotation to determine which data source to use when multiple are available.

• Spring Boot uses the @Primary annotation to specify the primary bean to be used when multiple beans of the same type are present.

• If no specific profile is defined, Spring Boot will use the bean marked with @Primary as the default data source.

• Developers can also use @Qualifier annotation to specify which bean to use if

Qualifier annotation is used in Spring framework to distinguish between beans of the same type.

• Qualifier annotation is used in Spring framework to resolve ambiguity when multiple beans of the same type are present.

• It is used in conjunction with Autowired annotation to specify which bean should be injected.

• For example, @Qualifier("myBean") can be used to specify a particular bean named 'myBean' to be injected.