#Java

Discuss the usage of various Spring Boot annotations such as @RequestMapping, @PathVariable, @RestController, and @Controller. How do they function in a Spring Boot application?

Describe an important multithreading concept or scenario you have encountered in your experience. (Note: Do not remember the exact question).

Design an algorithm to validate a string of parentheses. Provide your reasoning and a code example.

Write a function to find duplicate elements in a list using Java Streams. Include your thought process and a code example.

How would you find the second highest employee salary using Java Streams? Provide a code snippet to illustrate your solution.