30+ Advanced Java Interview Questions [Descriptive]

Get FREE domain for 1st year and build your brand new site

Free book on Graph Algorithms

Java is the one of the most Popular Programming Languages in the World with over 9M programmers using Java actively. This post cover the most advanced Java questions that are asked in Coding Interviews which several beginner programmers find difficult to answer correctly.

Practice more Java questions:

Following are Advanced Java Interview Questions [Descriptive] that you must attempt:

Name some Industry Standard Performance Benchmark for Java.

Some Industry Standard Performance Benchmark for Java are:

  • SPECcpu
  • SPECvirt_sc
  • SPECjbb
  • SPECjvm
  • SPECjEnterprise

Name some Application Profilers for Java.

Some Application Profilers for Java are:

  • VisualVM
  • JRockit Mission Control
  • Oracle Solaris Studio Performance Analyzer

What flags are used to enable JRE profiling and debug information?

Flags are used to enable JRE profiling and debug information are:

  • -XX:+PrintCompilation
  • -verbose:gc
  • -verbose:class
  • -Xprintflags

Name some Hardware Counters for Java applications.

Some Hardware Counters for Java applications are:

  • Sun Studio Performance Analyzer
  • oprofile
  • VTune

Name some tools to profile the entire system while running a Java application.

Some tools and commands to profile the entire system while running a Java application are:

  • top
  • htop
  • vmstat
  • mpstat
  • iostat
  • dtrace
  • strace

These are general commands and can be used to profile entire system while running any application beyond Java.

What is JavaOne?

JavaOne was an annual conference by Sun Microsystems to discuss Java technologies. It was first organized in 1996 and was one of the most popular conferences of its time.

Every conference featured a hardware device where Java is used. In 1998, it featured a finger ring which had Java embedded microprocessor.

In 1999, it has more than 20,000 attendees. Later as Sun Microsystems was acquired by Oracle, JavaOne was discontinued in 2018 and replaced by Oracle Code One which involves other technologies as well.

Name some Programming Languages other than Java that used JVM.

Some Programming Languages other than Java that used JVM are:

  • BeanShell
  • Clojure
  • Groovy
  • JRuby
  • Jython
  • Kotlin
  • Processing
  • Rhino
  • Scala
  • Oxygene

Name two Conferences focused on Java exclusively.

Two major Conferences that are focused exclusively to Java are:

  • JavaOne
  • Devoxx

What is JCA in Java?

JCA stands for Java Cryptography Architecture.

Java Cryptography Architecture is the platform, architecture and API for encryption and decryption in Java applications. JCA is used as a security measure and is used to enforced security rules. It has support for hash table, encryption message digest and much more.

What is JPA in Java?

JPA stands for Java Persistence API.

Java Persistence API is used to add support of persistence layer for Java applications. JPA includes:

  • Java Persistence API
  • Query Language
  • Java Persistence Criteria API
  • Object Mapping Metadata

How to generate Stack Trace in Java?

The following two statements can be used to generate stack trace of a Java program:

  • Throwable().printStackTrace() for stack trace of a method at a point.
  • Thread.currentThread.dumpStack() for stack trace of a current thread.

Example Java code snippet using Throwable().printStackTrace():

public static boolean download( String url)
{
    ........
    // If the download succeeded.
    if (success)
    {
        // see if the correct number of bytes were copied
        long newFileLength = new File(targetFile).length();
        if (expectedSize != newFileLength)
        {
            Debug.trace(1, url);
            Throwable().printStackTrace();
            return false;
        }
    }
    else
    {
        Debug.trace(1, url);
        return false;
    }
    ........
    return true;
}

What is Jikes in Java?

Jikes is an alternative to javac and is an open-source Java compiler developed by IBM. It is a high performing compiler but the user interface is limited and hence, is not widely used in general. It is used by IBM internally and for specific Java applications.

In Jikes:

  • Compiler is invoked by jikes command
  • Debugger is invoked by jd command

What is Java Swing?

Java Swing is a component of Java Foundation Classes which is used for Graphical User Interfaces.

Swing is used to create window based applications like desktop applications. It is built on top of an abstract windowing toolkit (AWT) API and is purely written in Java.

Java Swing is an alternative to Java AWT.

What are Java Applets?

Java applets are Java programs that can be embedded in a HTML page and run on the browser when pages are visited. It provides interactive features to web applications and can be executed by browsers on any platform.

This was one of the core features of Java to make it cross platform and was a driving feature for its initial success.

What is Java Beans?

Java Beans is a class that encapsulates many objects into one object so that it can be accessed from a single object. It is a Java technology that was first released in 1996 with JDK1.1.

With this article at OpenGenus, you must have a good practice of Advanced Java Interview Questions.