Citicorp Lead Java Developer Interview Questions and Answers

Q1. Asked about PL/SQL , JAVA 8 Fetaure, coding questions on Java, Coding questions on SQL asked.
Add your answer
Q2. Asked about Current project details, Agile, Devops related questions
Add your answer

Q1. Spring cloud gateway
Add your answer
Q2. JWT Token structure and details
Add your answer
Q3. Java 11 features
Add your answer
Q4. Stream related problems
Add your answer

Q1. Stringbuilder and string buffer diff
Add your answer
Q2. Where we store the object of string
Ans. 
Objects of String are stored in the String Pool in Java.
• String objects are stored in the String Pool, a special memory area in Java heap memory.

• String literals are automatically stored in the String Pool.

• String objects created using the new keyword are not stored in the String Pool.

• String.intern() method can be used to store a String object in the String Pool.
Answered by AI
Add your answer
Q3. What is bean in springboot
Ans. 
A bean in Spring Boot is a Java object that is instantiated, assembled, and managed by the Spring IoC container.
• Beans are defined in the Spring configuration file or using annotations like @Component, @Service, @Repository, etc.

• Beans are singleton by default but can be scoped as prototype, request, session, etc.

• Beans are injected into other beans using dependency injection.

• Example: @Component annotation is used to defi
Answered by AI
Add your answer
Q4. What is query parameters and path param
Ans. 
Query parameters are used to pass data to a web server through the URL, while path parameters are part of the URL itself.
• Query parameters are key-value pairs added to the end of a URL after a '?'

• Path parameters are variables within the URL path itself, denoted by curly braces {}

• Example of query parameter: www.example.com/api/users?id=123

• Example of path parameter: www.example.com/api/users/{userId}
Answered by AI
Add your answer
Q5. Code snippet related to exception
Add your answer
Q6. Diff between exception and error
Ans. 
Exceptions are recoverable errors that can be handled in code, while errors are unrecoverable issues that usually result in program termination.
• Exceptions are checked at compile time, while errors are unchecked.

• Exceptions are subclasses of Throwable, while errors are subclasses of Error.

• Examples of exceptions include FileNotFoundException, NullPointerException, while examples of errors include OutOfMemoryError, StackOv
Answered by AI
Add your answer

Q1. Quick sort - keep order same
Add your answer
Q2. Reverse string with spaces but keep the space position intact
Ans. 
Reverse a string while keeping the position of spaces intact
• Split the string into an array of characters

• Iterate through the array and reverse the characters while keeping track of space positions

• Join the array back into a string
Answered by AI
Add your answer

Q1. How is transaction managed in microservices architecture?
Ans. 
Transactions in microservices are managed using distributed transactions or compensating transactions.
• Distributed transactions involve multiple microservices coordinating with a transaction manager to ensure data consistency across services.

• Compensating transactions involve each microservice having a compensating action to rollback changes if a transaction fails.

• Saga pattern is commonly used in microservices to manage ...read more
Answered by AI
Add your answer
Q2. Questions about java garbage collection
Add your answer

Q1. What are checked and unchecked exceptions?
Ans. 
Checked exceptions are exceptions that must be either caught or declared in the method signature, while unchecked exceptions do not need to be caught or declared.
• Checked exceptions are subclasses of Exception class, excluding RuntimeException and Error.

• Checked exceptions are checked at compile time, so the compiler forces the programmer to handle them.

• Unchecked exceptions are subclasses of RuntimeException and Error cl...read more
Answered by AI
Add your answer
Q2. What is the difference between Spring and SpringBoot?
Ans. 
Spring is a framework for building Java applications, while SpringBoot is a tool that simplifies the setup and configuration of Spring applications.
• Spring is a comprehensive framework that provides various modules for different functionalities like dependency injection, aspect-oriented programming, etc.

• SpringBoot is an opinionated tool that simplifies the setup and configuration of Spring applications by providing defa...read more
Answered by AI
Add your answer

Q1. Difference between query and path param in spring boot
Ans. 
Query param is used to pass parameters in the URL query string, while path param is used to define parameters in the URL path itself.
• Query param is specified after the '?' in the URL, like '?param=value'

• Path param is specified in the URL path itself, like '/{param}'

• Query params are optional and can be used for filtering or sorting data

• Path params are used to define variables in the URL path, like IDs or names
Answered by AI
Add your answer
Q2. Difference between array and array list
Ans. 
Arrays have fixed size, while ArrayLists can dynamically resize. ArrayLists are part of Java Collections framework.
• Arrays have a fixed size, while ArrayLists can dynamically resize.

• Arrays can hold primitive data types and objects, while ArrayLists can only hold objects.

• Arrays use square brackets [] for declaration, while ArrayLists use angle brackets <>.

• Arrays are faster than ArrayLists for accessing elements directly ...read more
Answered by AI
Add your answer
Q3. Difference between abstract and interface
Ans. 
Abstract class can have both abstract and non-abstract methods, while interface can only have abstract methods.
• Abstract class can have constructors, fields, and methods, while interface cannot have any of these.

• A class can extend only one abstract class, but can implement multiple interfaces.

• Abstract classes are used to provide a common base for subclasses, while interfaces are used to define a contract for classes to ...read more
Answered by AI
Add your answer

3 coding questions were given and to be solved only in java