I applied through a recruiter. The process took 1 week. I interviewed at Datametica (Pune) in Sept 2019
Interview
1 Telephonic and 1 F2F. Once you clear the interviews, they will collect the documents and will never get back to you. HR does salary negotiation and al, but they do not release the offer.
Good questions asked in the interview. Mostly on core java. Round 1
Multithreading --why wait, notify and notifyall in object class?
Comparator and comparable present in which package?
Examples of immutable class other than string class?
Spring architecture?
Hashset internal implementation?
Hashtable internal implementation?
Hashmap internal implementation?
Why we prefer collections over array?
What will be output of following program
Class abc
{
Display(String abc) { }
Display(Integer abc) { }
}
Display(null);
What is marker interface? How JVM understands if an interface does not contain any method? Example of marker interface in java?
Java 8-- default methods? Then what's the difference between abstract class and interface? (multiple inheritance)
Merge sort? Given 2 sorted arrays of the same length? Merge them??
Round 2
Explain project architecture
2. Java Basics -- Abstraction and Encapsulation?
If I have a concrete class, is this class a breach to encapsulation?
3. Why getters and setters and not public variable
4. ConcurrentHashMap - What is concurrentModificationException? What will happens if 2 threads come for put operation
5. SQL Query
Employee Age Gender
A 10 M
B 20 M
C 30 F
D 40 F
E 50 M
Output: In a single query
Total Males Female>30
3 1
6. Singleton class? Volatile? Is data always read from Memory.. Thread cache? Smallest way to write a singleton
7. What is immutable class? getters need to return clone object
8. What is Method overloading and Method override? What will be output of following program
Class A {
void m1() {
sout ("Main Method")
}
}
Class B extends A {
void m1() {
sout ("Main Method")
}
}
Class C {
public void callm1(A a) {
a.m1();
}
public void callm1(B b) {
b.m1();
}
main() {
A a = new B();
c.callm1(a);
}
}
9. Parent class method throws FileNotFoundException and child class method throws Exception?? Is this allowed?
10. Generics --> What will be the output of following program
List<Integer> al = new ArrayList<>();
al.add(1);
m1();
sout(al);
void m1(List al) {
al.add("Data");
}
11. Do you know about Trees? BellMon Ford.. Binary search tree? Tree traversal - (BFS and DFS)? Shortest path - Dijkstra's? Graph
Interview questions [1]
Question 1
7. What is immutable class? getters need to return clone object
I applied through a staffing agency. The process took 1 day. I interviewed at Datametica (Pune) in Nov 2018
Interview
The process was good and bit impressive. The interviewer was keeping on focus on syntax rather than concept. If you just try to make him understand through concept or design then he would not get your point.
