I’m building a small online-banking proof-of-concept and need a concise Core Java module that focuses solely on transaction processing. The code must run on plain Java (no Spring or heavy frameworks) and use JDBC for all data access. Scope of work • Implement deposit and withdrawal operations against a single Checking Account type. • Persist balances and transaction ledgers in a relational database of your choice via clean, parameterized JDBC calls. • Include basic validation—insufficient funds, negative amounts, and duplicate transaction IDs should be gracefully handled with clear error messages. • Write a minimal CLI or simple Swing form to demonstrate each use-case end-to-end. Deliverables 1. Well-structured Java source (JDK 8+), SQL schema, and a small seed script. 2. README with compile/run instructions and a quick test walkthrough. 3. A short note explaining any design patterns or decisions you applied. Acceptance criteria • All unit tests you provide pass; manual testing confirms deposits increment and withdrawals decrement the balance correctly and atomically. • Code follows standard naming conventions and compiles without warnings. If you have recent JDBC work or a snippet that shows clean transaction handling, please point me to it; it will help me shortlist quickly.