Fujitsu Interview Questions, Process, and Tips

Explanation of final, finally and finalize in Java with examples

• final is a keyword used to declare a constant value or to prevent method overriding or class inheritance

• finally is a block of code that executes after try-catch block, regardless of exception occurrence

• finalize is a method that gets called by garbage collector before destroying an object

• final is used for declaring constant values, method parameters, and lo...read more

The different layers of Springboot application, webservers that come with Springboot, default webserver, changing default webserver, and configuring port on spring-boot.

• The different layers of Springboot application are presentation layer, service layer, business layer, and data access layer.

• The webservers that come with Springboot are Tomcat, Jetty, and Undertow.

• The default webserver is Tomcat.

• To change the default we...read more

Java has four types of references: strong, weak, soft, and phantom.

• Strong references are the default and are used to refer to objects that are still in use.

• Weak references are used to refer to objects that can be garbage collected when there are no strong references to them.

• Soft references are used to refer to objects that should be garbage collected only when memory is low.

• Phantom references are used to track when an ...read more

Answering questions related to Kubernetes deployment file, image pulling, and QoS for pods.

• Fields in deployment file: apiVersion, kind, metadata, spec (replicas, selector, template)

• Ways of pulling images: using imagePullPolicy (Always, IfNotPresent, Never), specifying image name and tag

• QoS for pods: Guaranteed (requests and limits specified), Burstable (only requests specified), BestEffort (no requests or limits specif

Kafka is a distributed streaming platform that allows publishing and subscribing to streams of records.

• Kafka works by having producers publish messages to topics, which are then stored in partitions on brokers.

• Consumers subscribe to topics and read messages from partitions.

• To debug if messages are not received, use the command-line tool kafka-console-consumer to check if messages are being produced and consumed.

• Also ch...read more

Yes, reflection is a feature in Java that allows inspecting and modifying runtime behavior of a program.

• Reflection allows accessing and modifying fields, methods, and constructors of a class at runtime.

• It is useful for creating generic code, debugging, and testing.

• Example: getting the class name of an object using getClass() method.

• Example: accessing private fields of a class using reflection.

• Example: creating an insta

Inversion of Control is a design pattern where control is inverted from the application to a framework.

• In Springboot, a bean is created by annotating a class with @Component or its specialized annotations like @Service, @Repository, etc.

• Beans are injected using @Autowired annotation or constructor injection.

• Bean resolution is done by the Spring container which maintains a registry of all beans and their dependencies.

• In...read more

Inner classes are used for encapsulation and code organization. Static inner classes are used for utility classes.

• Inner classes are used to group related classes together and improve encapsulation.

• Non-static inner classes have access to the outer class's fields and methods.

• Static inner classes are used for utility classes that don't need access to the outer class's fields and methods.

• Inner classes can also be used for

Implementing an iterator for a custom object

• Create a custom class and implement the Iterable interface

• Override the iterator() method to return a custom Iterator object

• Implement the hasNext() and next() methods in the Iterator class

• Use the for-each loop to iterate through the custom object

A controller class in Springboot is used to handle REST API requests and responses.

• Annotate the class with @RestController

• Define methods for each API endpoint with @RequestMapping annotation

• Use appropriate HTTP methods like GET, POST, PUT, DELETE

• Inject dependencies using @Autowired annotation

• Return response using ResponseEntity class

StatefulSets are used for stateful applications that require stable network identities and persistent storage.

• StatefulSets are used for applications that require ordered deployment, scaling, and termination.

• They provide stable network identities and persistent storage for each pod in the set.

• Storage mapping is done using PersistentVolumeClaims (PVCs) which are bound to PersistentVolumes (PVs).

• Each pod in the StatefulSe...read more

Using Java 8 streams, search for a given string in a list of Strings.

• Create a stream from the list of Strings

• Use the filter() method to filter out the Strings that do not contain the given string

• Collect the filtered Strings into a new list using the collect() method