Advanced Java Interview Questions- Part 6

LISTEN TO THE ADVANCED JAVA FAQs LIKE AN AUDIOBOOK

Advanced Java Interview Questions- Part 6If you are aiming for a Java Developer role, knowledge of advanced Java is a must. Prepare these Common Java interview questions. You must be fluent with concepts like Multithreading, Concurrency, Design Patterns, Memory Management, Streams, Lambda Expressions, Spring Framework, and Performance Optimization. All these skills are essential for high-paying Java jobs.

In this interview questions guide, we have covered all the important questions that interviewers ask most. By going through our interview questions guide, you will be able to master all key concepts and prepare answers for the interview.

Start reading and learning to go one step closer to your dream job!

Answer:

Unicode characters have several advantages, as listed in the table below:

Advantages Explanation
Simplifies app development When a Java Developer uses Unicode, all symbols needed by the application for writing & reading character data reside in a single code page, which simplifies app development.
Ease of migrating the existing code A Unicode-based encoding, UTF-8 comprises the traditional ASCII characters in its first 127 positions & it assigns each of these characters in its traditional ASCII value. Thus, it simplifies adapting existing ASCII applications to Unicode.
Facilitates shared access to data OpenEdge applications’ clients that use incompatible code pages can easily write & read a single UTF-8 database. Thereon, OpenEdge will automatically convert the code page as data passes between the database & the client.
Streamlines worldwide deployment r-code files & UTF-8 databases are multi-lingual that can be deployed worldwide.
Interoperability Java clients & Active-X are Unicode based; hence they can communicate with App servers & UTF-8 databases.
Web compatibility Unicode has become the universal code page of the Web. Therefore, the Current Web standards rely on Unicode.
Multi-lingual applications A Unicode-based application can support multiple languages such as; Data, Reports, & User interface.

Answer:

The hashCode of an object is a number that helps hash-based data structures to manage an object. It is a unique number assigned to an object by Java Virtual Machine. However, if two objects are equals, then both the objects will have the same hashCode. Implementing the hashCode() method in a class should be in a way that if two objects are the same when compared by equal() method, then those two objects must return the same hashCode. Thus, both equals() & hashCode() method should be overridden.

Answer:

Java uses Garbage Collection for efficient memory utilization. The garbage collector’s primary objective is to free up memory by detecting unused objects & deleting them. A Garbage Collector gets automatically invoked and doesn’t assure the required memory for a program to run.

Answer:

The finalize () is a special method in Object class that the garbage collector calls to do the necessary clean-up before an object’s destruction. It can be overridden by any class that uses system resources & needs to release those resources or perform other clean-ups as part of the garbage collector’s implicit destruction.

Answer:

The @Transactional must use the service layer as it contains the business logic. The service layer is the best place to add @Transactional annotations as it has detail level use-case behavior & most of the business logic present here.