HCL Group Team Lead Interview Questions, Process, and Tips for Experienced

Adding list of employees using stream and Lambda expression

• Create a list of employees as an array of strings

• Use the stream() method to convert the array into a stream

• Use the forEach() method to iterate through the stream and add each employee to the list

• Use a Lambda expression to add each employee to the list

Hash set uses hashing function to store unique values and avoid duplication.

• Hashing function generates a unique hash code for each value

• The hash code is used as an index to store the value in the hash set

• If a new value has the same hash code as an existing value, it is considered a duplicate and not added to the set

Index is a data structure used to improve the speed of data retrieval operations.

• An index is created on one or more columns of a table.

• It stores a copy of the indexed data in a separate structure.

• The index is organized in a way that allows for fast searching and sorting of data.

• Different types of indexes include B-tree, hash, and bitmap indexes.

• Indexes can improve query performance but can also slow down data modificat

Query to find second highest salary from Employee table

• Use ORDER BY and LIMIT to get the second highest salary

• SELECT salary FROM Employee ORDER BY salary DESC LIMIT 1,1

• If there are ties for the highest salary, this query will return the next distinct salary

Spring Boot provides various security mechanisms such as authentication, authorization, and encryption.

• Spring Security is the main security framework used in Spring Boot

• It provides features like authentication, authorization, and session management

• Spring Boot also supports OAuth2 and JWT for secure authentication and authorization

• Encryption can be achieved using HTTPS and SSL/TLS protocols