JAVA is one of the most important platforms on which almost all multinational companies like Accenture works. I am sure you are preparing for Accenture job interviews. I would highly recommend you to go through all the HR, written and technical Accenture interview questions with answers here. Below are 10 popular questions and answers asked in the Accenture interviews related to JAVA.
- What are the different types of class loaders in JAVA?
There are three different types of class loaders.
The System Class Loader is a class loader that loads codes which are found in java.class.path which maps with CLASSPATH environment variable.
The jar packages contained in JAVA_HOME/jre/lib/ext which are extensions of core classes of java are loaded by the Extensions Class Loader from the ‘ext’ folder.
This loader loads the core java classes like java.lang or java.util. These classes are the eminent part of the java runtime environment.
- What is JAVA Reflection API?
Reflection is one of the most important API used I JAVA which enables a user to work with the java classes, variables and methods in a dynamic way. this API inspects the java class attributes at the runtime process and provides metadata about the classes too.
- What is immutable object?
The object in classes which when created cannot be modified is called Immutable object. If there is any modification done to the object the previous will no longer exist and a new object will form.
- What is the basic difference between Externalizable and Serializable interfaces?
Both the above mentioned interfaces are used for serialization implementation. The basic difference between these two closely related interface is that Serializable interface has no method whereas Externalizable has two methods which are readExternal() and writeExternal(). Serializable interface acts like a marker interface.
- What is Daemon Thread?
The thread that still runs when the program has finished and does not stop Java Virtual Machine from exiting is called Daemon Thread. This runs in the background to carry on certain programs like housekeeping and garbage collection.
- What is the basic difference between Index Access and Iterator Access?
Index Access processes the elements directly by using the proper index whereas in Iterator Access the cursor traverses through every element to get the required or intended element. Updation, deletion or insertion via Iterator Access is faster when the elements are present in the data structures. In case of Index Access it will be faster when the data is present at the last.
- What are the two methods used to implement key Object in HashMap?
The two methods that must be used to implement any object as Key in the process of HashMap are ‘equals’ and ‘hash code’ methods.
- What will be problem when hashcode() method is not overridden?
When the override process is not done in hashcode() method the user will be unable to recover the object from the Map.
- Is non static variable accessible in the case of static context?
The non static variable is inaccessible in case of static context.
- What is the process to read and write an image from a file?
By using ImageIO.write() and ImageIo.read() method of javax.imageio package we can write and read an image file respectively.