Dynamic Aspect Weaving AOP fundamentally separates business logic from cross-cutting concerns. This separation provides several advantages: Aspect code needs to be written only once Developers focus solely on business logic without duplicating cross-cutting code Aspects are dynamically woven into bu...
Problem Description Given two non-empty linked lists representing non-negative integres in reverse digit order, combine the numbers and return the result as a linked list. Basic Iterative Approach class Solution { public ListNode addTwoNumbers(ListNode first, ListNode second) { ListNode dummyHead =...
1. Verifying Identical Binary Trees Given two binary trees, determine if they are structurally identical with matching node values at every position. Empty trees are considered identical. Analysis: The solution requires recursive comparison of corresponding nodes. When both nodes are null, they matc...
System Architecture and Optimization Strategy Implementing user authentication using Apache Struts 2 and flat-file storage is a common exercise for understanding the Model-View-Controller (MVC) pattern. While production environments typically rely on relational databases, optimizing a TXT-based user...
Problem 1: Free Drink Days **Problem Description:**Given N consecutive days of temperature and the starting day of the week, calculate how many days you can get free drinks (when temperature ≥ 35°C) and how many days you couldn't get free drinks specifically because it was Thursday. **Input Format:*...
Parallelism vs Concurrency Parallelism refers to multiple threads executing simultaneously across different processors at the exact same moment. Concurrency involves rapid context switching between threads on a single processor, creating the illusion of simultaneous execution. Thread Lifecycle State...
Thread Safety and Multithreading Fundamentals When multiple threads access shared resources, synchronized blocks ensure that only one thread can execute a critical section at a time. While utilizing multiple locks can increase concurrency by allowing different threads to access distinct components o...
Theoretical Foundations of Concurrency Understanding Programs and Processes A program represents static code that serves as the blueprint for application execution. In contrast, a process is the dynamic execution of a program, encompassing the entire lifecycle from code loading to completion. Operat...
A production incident revealed duplicate data creation: a single save operation resulted in three database records. Investigation traced the issue to inconsistent retry behavior between Dubbo’s XML and annotation-based configuration for retries = 0. In XML configuration, the following disables retri...
SQL Injection Vulnerabilities JDBC Concatenation Flaws Direct string concatenation in SQL queries without input validation creates injection vectors. When user-supplied parameters embed directly in to query strings, attackers can manipulate query logic. Vulnerable Pattern: public User fetchUserDetai...