In contrast to Java IO which primarily a stream based mostly API, Java NIO makes use of Channels for studying and writing knowledge, and this one factor improves the efficiency of IO in Java software. Java NIO additionally supplies non-blocking and asynchronous Enter output operation.
This implies, you should utilize Java NIO API to create high-performance, non blocking servers in Java.
10 Java NIO Interview Questions for five to 10 Years Skilled Builders
With out losing anymore of your time, here’s a listing of fashionable Java NIO interview questions. These questions covers important ideas and courses from Java NIO API like Channel, Selector, ByteBuffer and non blocking IO.
You probably have used Java NIO in any of your undertaking then you may simply reply these questions but when you have not then its powerful cookie to crack. However, even if in case you have not labored in NIO, which is kind of frequent as a lot of use larger order libraries like Apache MINA for networking stuff which makes use of Java NIO beneath, then these questions will enable you to be taught Java NIO higher.
1. If you must pay attention on three sockets from the Java program, what number of threads will you want? three or one?
In case you are utilizing previous Java NIO API then you’ll use a number of thread to pay attention for various sockets however in case of Java NIO, you should utilize only one thread and it will probably hearken to a number of sockets utilizing Selector. That is the facility of Java NIO and non-blocking performance it supplies.
Here’s a diagram which exhibits how blocking IO works in Java:
And, here’s a diagram which exhibits how you should utilize single thread to hearken to a number of sockets utilizing Selector class from Java NIO API
2. How does the selector work in Java NIO? (reply)
3. What’s distinction between blocking and non-blocking IO in Java? (reply)
4. Distinction between normal IO and NIO in Java? (reply)
5. How do you create ByteBuffer in Java? (reply)
You’ll be able to create ByteBuffer utilizing allocate() and allocateDirect() technique in Java. The allocate() technique ceate a non-direct byte buffer inside heap reminiscence whereas allocateDirect() technique creates a direct byte buffer outdoors heap reminiscence.
6. Distinction between ByteBuffer and StringBuffer in Java? (reply)
Each are fairly completely different, like evaluating oranges to apple. ByteBuffer is usually a wrapper round byte array or can reference to reminiscence outdoors heap whereas StringBuffer is a Java class which is used to signify mutable String in Java. Since String is Immutable in Java and any operation on String creates new String object, you should utilize StringBuffer so as to add, take away or replace character kind String with out creating new objects.
7. Distinction between Direct and Non-Direct ByteBuffer in Java? (reply)
Java NIO lets you learn and write from reminiscence which is outdoors of heap reminiscence. There are three principal sorts of ByteBuffer in Java, direct, non-direct and reminiscence mapped byte buffer. Predominant distinction between them is that Direct byte buffer operates on reminiscence which is allotted outdoors heap whereas non-direct byte buffer is only a a wrapper round byte array allotted from the heap reminiscence.
Due to that direct byte buffer are additionally not affected by Rubbish assortment. You’ll be able to create a direct byte buffer by utilizing allocateDirect() technique of ByteBuffer in Java.
8. The right way to convert byte[] to lengthy in Java? (reply)
10. What’s the byte order of ByteBuffer, BIG endian or LITTLE endian? (reply)
11. Distinction between Channel and Stream in Java? (reply)
12. What’s Reminiscence mapped byte buffer? how do you create them? (reply)
Reminiscence mapped byte buffer is a sort of direct byte buffer in Java. It’s created by MappedByteBuffer class which is subclass of ByteBuffer class. You’ll be able to create a reminiscence mapped buffer utilizing FileChannel.map() technique.
That is all about fashionable Java NIO Interview questions. I’ve not given solutions of those questions to be able to do bit extra analysis and discover solutions however if in case you have bother discovering solutions, do let me know in feedback and I’ll add reply to those questions. As I mentioned, these questions covers important Java NIO ideas and courses and fairly necessary for senior Java developer who are sometimes tasked to put in writing backend code. I’ve additionally linked to earlier articles the place I’ve mentioned these NIO questions in particulars
Different Interview Questions articles it’s possible you’ll like
Thanks
for studying this text to date. In the event you like these Java NIO interview
questions then please share them with your folks and colleagues. If
you might have any questions or suggestions then please drop a word.
