What is interface and abstract class.

Jan. 21 | What is interface and abstract class. (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

What is dead lock.

Jan. 21 | What is dead lock. (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

What is synchronized block ,static block .

Jan. 21 | What is synchronized block ,static block . (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

How hash map works internally.

Jan. 18 | How hash map works internally. (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

Difference between hashmap and hash table and concurrent hashmap.

Jan. 18 | Difference between hashmap and hash table and concurrent hashmap. (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

Difference between arraylist and vector.

Dec. 30 | Difference between arraylist and vector. (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({});

Can a constructor in Java be private or final?

Nov. 19 | 73 down vote Yes, a constructor can be private. There are different uses of this. One such use is for the singleton design anti-pattern, which I would advise against you using. Another, more legitimate use, is in delegating constructors; you can have...

how do you enforce garbage selection?

Nov. 4 | Under the documentation for OutOfMemoryError it declares that it will not be thrown unless the VM has failed to reclaim memory following a full garbage collection. So if you keep allocating memory until you get the error, you will have already forced...

difference between synchronized hashmap and concurrent hashmap?

Nov. 4 | ConcurrentHashMap. It allows concurrent modification of the Map from several threads without the need to block them. Collections.synchronizedMap(map) creates a blocking Map which will degrade performance, albeit ensure consistency (if used properly)....

how do you avoid creating a new instance while deserializing an object?

Nov. 4 | Here is my code which serializes, and deserializes. FileOutputStream fos = new FileOutputStream(“myserial1.txt”); ObjectOutputStream oos = new ObjectOutputStream(fos); Elvis e = Elvis.getInstance(); System.out.println(” e = “+e.getInstance());...