Top 12+ Senior Java Developer Interview Questions and Answers


Wait() pauses the thread until the specified number of milliseconds has passed or it receives a notification from another thread, whichever instance occurs first. This function does not keep a hold on the monitor or lock the shared object. An application context is similar to a bean factory in that both are capable of loading definition, wiring beans together, and dispense beans upon request. It also separates application business logic from system services to enable cohesive development. Our mission is to make it easier for developers to find great remote jobs with high-quality companies, and we’re on a mission to help as many people as possible! You can search or post your own listings of freelance or full-time opportunities in our marketplace.

One of the more asked Java coding interview questions, this might not seem like an “advanced” one at first. However, things like aggregation and composition stem from the association, so it is important to understand the term. A class can extend only one abstract class but it can be implemented into multiple interfaces. I’ve already mentioned JVM previously – it stands for Java Virtual Machine. It’s a machine that creates the environment in which Java bytecode can function properly. It’s the main tool in Java used to compile the programs of this language.

Why Java doesn’t support multiple inheritances?

Java is not said to be pure object-oriented because it supports primitive types such as int, byte, short, long, etc. I believe it brings simplicity to the language while writing our code. Java could have wrapper objects for the primitive types but just for the representation, they would not have provided any benefit. Java Development Kit is for development purposes and JVM is a part of it to execute the java programs.


In your Java interview questions, you are more than likely to get mostly comparison-type ones. This update to the programming language was one of the more notable ones – it would be beneficial to know what new features emerged from it. We’ll talk about Java 8 interview questions and I’ll provide answers for experienced developers. Let’s start from the beginning, though, and jump into the basics. The latest spring security course covers Spring Security, Authentication, Authorization, Users, Roles, Authors, CORs, CSRF, JWT, OAuth2, and more. You can also see my article 25+ Spring security interview questions for answers to these and some other questions for examples.

Write a Java program to create and throw custom exceptions.

From java interview questions for senior developer 7, we can create resources inside try block and use it. Java takes care of closing it as soon as try-catch block gets finished. If we have to use any static variable or method from other class, usually we import the class and then use the method/variable with class name. We can’t declare a top-level class as static however an inner class can be declared as static. If the inner class is declared as static, it’s called a static nested class. The java.langpackage is imported by default and we don’t need to import any class from this package explicitly.

java programming language

Fail-fast iterators utilize a ConcurrentModificationException; fail-safe iterators do not throw such an exception. Spring uses the technique of IoC to achieve loose coupling and give objects their dependencies instead of creating or searching for dependent objects. The basic version of the Spring framework is around 2MB, making Spring lightweight in terms of size and transparency. The Java Runtime Environment is essentially the JVM where Java programs are being executed.

How do you show a diamond problem with multiple inheritance in Java?

Synchronization is a process that keeps all concurrent threads in execution to be in sync. The process of synchronization allows avoiding memory consistency errors caused due to an inconsistent view of shared memory. When a method is declared as synchronized the thread holds the monitor for that method’s object.

Classpath is specific to Java and used by java executables to locate class files. We can provide the classpath location while running the java application and it can be a directory, ZIP files, JAR files, etc. As we know, for all the primitive types we have wrapper classes such as Integer, Long etc that provides some additional methods.

There are two ways to define and implement a thread in Java. They are by implementing the runnable interface and extending the thread class. Each catch block must have a unique exception handler. So, if you want to perform multiple tasks in response to various exceptions, use the Java multi-catch block. Method overloading occurs during the compile time, whereas method overriding occurs during the run time. Static binding is used during overloading, whereas dynamic binding is used during methods overriding.

Also, the scope is limited to the code segment where the variable is declared. For instance, variables are declared inside a class, and the scope of variables in javascript is limited to only a specific object. The package is a collective bundle of classes and interfaces and the necessary libraries and JAR files. No, Java cannot be treated as a complete object-oriented programming language. Stack memory in data structures isthe amount of memory allocated to each individual programme.

We have gathered 25 most asked senior developer interview questions and answers so that you know what to expect when going into your next interview. With a need for programmers on the rise, multiple companies and individual employers are looking for experienced professionals in the field of computer coding. Because Java is one of the most popular programming languages in the world , many potential programmers choose it as their primary language to learn. In this tutorial, I’ve shown you some core Java interview questions and answers. There are many more Java coding interview questions that you might get asked during your job interview, but if you know these, you’re already set on a good path.

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This is probably going to be one of the main Java 8 interview questions that you’ll receive. Just keep in mind that Java 8 was a huge improvement both performance and security-wise, and you should be good to go. Overall, Java 8 made the programming language more accessible and better in-line with modern-day programming languages. For beginner programmers and developers, the most important feature is simplicity. Java is considered to be quite easy to learn and master, especially when compared with other programming languages out there.

When a programme is run, an active instance of the programme called a process is launched. A process is begun by a programme once it has been run. The process carries out the program’s specified instructions. A local variable can be anywhere inside a method or a specific block of code.

I am so greatfull that you have shared all questions and answers. System class is final so that we can’t subclass and override its behavior through inheritance. System class doesn’t provide any public constructors, so we can’t instantiate this class and that’s why all of its methods are static. The object should implement a Serializable interface and we can use to write objects to file or to any OutputStream object. This keyword provides the reference to the current object and it’s mostly used to make sure that object variables are used, not the local variables having the same name.

Provide a default set of root Certification Authority certificates in the JDK. Most of the interviewers enjoy back and forth brainstorming and prefer the ideation process to be more of a discussion about how to solve the problem. Unfortunately, when we pass the value of an object, we are passing the reference to it. There is no such thing as “pass-by-reference” in Java. JUnit is the renowned unit-testing framework in the Java ecosystem.

  • Composition is a way of describing reference between two or more classes using instance variables and an instance should be created before it is used.
  • Enum was introduced in Java 1.5 as a new type whose fields consist of a fixed set of constants.
  • In this case, since the first literal would return true, it would skip the second literal evaluation.
  • Most other high-level languages are compatible with C++.
  • Here are some basic Spring MVC questions covering concepts such as spring MVC workflow, controllers, view resolution, servlet dispatcher, and common spring MVC statements.

There are lots of applications and websites that will not work unless Java is installed in them. Each day there are more and more applications created using Java. It is a very simple, powerful and robust programming language which provides a fast, secure, and reliable platform to work on. Java is being used everywhere, from laptops to data centers, game consoles to scientific supercomputers, and cell phones to the Internet.

Because Java programmes can operate on numerous systems without having to be individually rewritten for each platform, the language is referred to as “Write Once, Run Anywhere” . Java is a programming language and also a platform for computing. Java was first released by Sun Microsystems in 1995.