Round 1
Questions:
- Tell me about yourself.
- Create a class named
Employee
and create entries viaList<Employee>
. Fetch the employee name who is "manager" using Stream API. - Sort a
HashMap
according to the key using Stream API. - Questions on design patterns (Singleton pattern and Factory design pattern).
- How does hashing work internally in
HashMap
? - Difference between
HashMap
andTreeMap
? - Explain functional interfaces and any pre-defined functional interface.
- SQL: Write a SQL query to find employees who are managers and whose joining date is in the month of August.
- Difference between
TRUNCATE
andDELETE
. - How does a Spring Boot application start?
- How to create a new Spring Boot application?
- What are
@GetMapping
and@PostMapping
? - Difference between
@QueryParam
and@PathParam
.
Below is my code snippet:
import java.util.ArrayList; import java.util.HashMap; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; import java.util.stream.Collectors; public class hsc { public static void main(String[] args) { List<Employee2> aList = new ArrayList<Employee2>(); aList.add(new Employee2("Yash", "Manager")); aList.add(new Employee2("Nishant", "Employee")); aList.add(new Employee2("Priti", "HR")); List<Employee2> finaList = aList.stream() .filter(x -> x.getDesignation().equals("Manager")) .collect(Collectors.toList()); HashMap<String, String> hMap = new HashMap<String, String>(); hMap.put("Surya", "Football"); hMap.put("Aditi", "Basketball"); hMap.put("Yash", "Chess"); //to perform sort on basis of name Map<String, String> collect = hMap.entrySet() .stream().sorted(Map.Entry.comparingByKey()) .collect(Collectors.toMap(Map.Entry :: getKey, Map.Entry :: getValue, (oldValue, newValue) -> oldValue, LinkedHashMap::new)); System.out.println(collect); System.out.println(finaList.toString()); singletonExample singlet1 = singletonExample.getInstance(); singletonExample singlet2 = singletonExample.getInstance(); System.out.println(singlet1); System.out.println(singlet2); } } class Employee2{ private String name; private String designation; public Employee2(String name, String designation) { this.name = name; this.designation = designation; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getDesignation() { return designation; } public void setDesignation(String designation) { this.designation = designation; } @Override public String toString() { return "Employee2 [name=" + name + ", designation=" + designation + "]"; } }
public class singletonExample { private static singletonExample singletonExample2; private singletonExample() { } public static singletonExample getInstance() { if(singletonExample2 == null) singletonExample2 = new singletonExample(); return singletonExample2; } }
I answered all the questions correctly and smoothly. Still Rejected.
Candidate's Approach
The candidate created a class Employee2
and used a List
to store employee entries. They utilized Stream API to filter and fetch employees with the designation "Manager". For sorting a HashMap
, they applied Stream API to sort by keys and collected the results into a LinkedHashMap
. The candidate also implemented a Singleton pattern and provided explanations for design patterns and SQL queries as requested.
Interviewer's Feedback
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