20+ Kalimati Global Shared Services Interview Questions and Answers

Microservices offer advantages such as scalability, flexibility, and easier maintenance.

• Scalability: Microservices allow for individual components to be scaled independently, making it easier to handle high traffic.

• Flexibility: Microservices can be developed and deployed independently, allowing for faster development and deployment cycles.

• Easier maintenance: Microservices are smaller and more focused, making it easier to identify and fix issues.

• Example: Netflix uses microserv...read more

Program to get the middle of a linked list in a single iteration using two pointers.

• Use two pointers, slow and fast, to traverse the linked list

• Move slow pointer one step at a time and fast pointer two steps at a time

• When fast pointer reaches the end, slow pointer will be at the middle node

Singleton is a design pattern that restricts the instantiation of a class to one object.

• Singleton pattern is used when we need to ensure that only one instance of a class is created and used throughout the application.

• To implement Singleton, we make the constructor private and provide a static method to get the instance of the class.

• Singleton can be broken by using reflection, serialization, and cloning.

• Reflection can be used to access the private constructor and create a new...read more

To switch from one branch to another in git, use the 'git checkout' command.

• Use 'git checkout' followed by the name of the branch you want to switch to.

• Make sure to commit or stash any changes before switching branches.

• Example: 'git checkout new-branch'

Maven clean removes target directory and install compiles and packages the project

• Maven clean removes the target directory and all the compiled classes and resources

• Maven install compiles and packages the project and installs the resulting artifact into the local repository

• Maven clean and install together ensure that the project is built from scratch and all dependencies are resolved

• Useful when there are changes in the project dependencies or configuration

APIs can be secured using various methods such as authentication, encryption, rate limiting, and input validation.

• Implement authentication using OAuth or JWT

• Use HTTPS encryption to protect data in transit

• Implement rate limiting to prevent DDoS attacks

• Validate input data to prevent injection attacks

• Regularly update and patch software to prevent vulnerabilities

Deadlock is a situation where two or more threads are blocked and waiting for each other to release resources.

• Deadlock occurs when two or more threads are waiting for each other to release resources.

• It can be resolved by using techniques like resource allocation graph, timeout, and prevention.

• Prevention can be done by avoiding circular wait, hold and wait, and no preemption.

• Example: Thread A holds resource X and waits for resource Y, while Thread B holds resource Y and waits ...read more

A Future object represents the result of an asynchronous computation in Java.

• Future objects are used to retrieve the result of an asynchronous computation when it becomes available.

• They provide a way to check if the computation is complete, cancel the computation, and retrieve the result.

• They are commonly used in multithreaded programming and in Java's Executor framework.

• Example: Future future = executor.submit(new Callable() { public Integer call() { return 42; }});

• Example: ...read more

HashMap is a data structure that stores key-value pairs and uses hashing to retrieve values quickly.

• HashMap uses hashing to store and retrieve values quickly

• It uses an array of buckets to store key-value pairs

• The hash code of the key is used to determine the bucket where the key-value pair is stored

• If two keys have the same hash code, they are stored in the same bucket as a linked list

• When retrieving a value, the hash code of the key is used to find the bucket and then the li...read more

Spring filter is an interface used to intercept HTTP requests and responses.

• Spring filter is used to perform tasks such as logging, security, and caching.

• It can be used to modify the request or response before it reaches the controller.

• Examples of Spring filters include CharacterEncodingFilter, CorsFilter, and CsrfFilter.

A convenience annotation that combines @Configuration, @EnableAutoConfiguration, and @ComponentScan.

• Used to bootstrap a Spring Boot application.

• Automatically configures the Spring application based on the dependencies added to the classpath.

• Scans the package and its sub-packages for components and services.

• Example: @SpringBootApplication public class MyApplication { public static void main(String[] args) { SpringApplication.run(MyApplication.class, args); } }

Disadvantages of what? Please specify.

Save() method inserts a new record into the database, while persist() method can also be used to update an existing record.

• save() method is used to insert a new record into the database

• persist() method can also be used to insert a new record, but it can also be used to update an existing record

• save() method returns the generated ID immediately, while persist() method does not

• save() method can be called outside of a transaction, while persist() method must be called within a t...read more

Hibernate manages object lifecycle through three states: transient, persistent, and detached.

• When an object is created, it is in the transient state.

• When the object is saved using session.save() method, it becomes persistent.

• When the session is closed or the object is explicitly detached using session.evict() method, it becomes detached.

• Detached objects can be re-attached to a new session using session.update() or session.merge() methods.

• Objects can also be deleted using sess...read more

Merge overlapping intervals in Java

• Sort the intervals based on their start time

• Iterate through the intervals and merge overlapping ones

• Use a stack to keep track of merged intervals

Stack peek returns the top element without removing it, while stack pop removes and returns the top element.

• Stack peek is used to check the top element of the stack without removing it.

• Stack pop is used to remove and return the top element of the stack.

• Both methods operate on the top element of the stack.

RequestMapping is used for all HTTP methods while PostMapping is specifically for POST requests.

• RequestMapping is a general-purpose annotation for mapping HTTP requests to handler methods.

• PostMapping is a specialized version of RequestMapping that only maps POST requests.

• RequestMapping can be used for GET, POST, PUT, DELETE, and other HTTP methods.

• PostMapping is useful when you want to handle only POST requests and ignore other HTTP methods.

• Example: @RequestMapping(value = "/...read more

RestController is used for RESTful web services while Controller is used for traditional web applications.

• RestController returns data in JSON or XML format while Controller returns data in HTML format.

• RestController uses @RestController annotation while Controller uses @Controller annotation.

• RestController is used for building RESTful web services while Controller is used for building traditional web applications.

• RestController is a specialized version of Controller in Spring...read more

Linked list is dynamic and efficient for insertion/deletion, while ArrayList is faster for random access.

• Linked list uses pointers to connect nodes, while ArrayList uses an underlying array.

• Linked list is better for frequent insertion/deletion, while ArrayList is better for frequent random access.

• Linked list has O(1) time complexity for insertion/deletion, while ArrayList has O(n) time complexity.

• Example: Linked list is used in implementing stacks, queues, and hash tables, wh...read more