Java SE 17: Programming Complete — Lesson 3: Exceptions, I/O, NIO.2, Serialization Awareness, Threads, and Concurrency

Learning Objectives

• Explain the purpose and operating context of checked and unchecked exceptions, try-with-resources, and custom exceptions.
• Apply files, paths, streams, readers, writers, NIO.2, and directory operations and serialization risks awareness, object boundaries, and safe data formats in a controlled environment.
• Validate outcomes and troubleshoot risks involving threads, executors, futures, locks, atomic types, concurrency collections, and race tests.

Detailed Topics

• checked and unchecked exceptions, try-with-resources, and custom exceptions
• files, paths, streams, readers, writers, NIO.2, and directory operations
• serialization risks awareness, object boundaries, and safe data formats
• threads, executors, futures, locks, atomic types, concurrency collections, and race tests

Instructor Demonstration

Demonstrate checked and unchecked exceptions, try-with-resources, and custom exceptions for a modular Java application implemented from core language design through concurrent processing and database integration; capture the exact configuration, code, command, transaction, query, dashboard, model, schedule, or report evidence that proves the expected result.

Hands-On Exercise

Complete a controlled Java SE 17: Programming Complete exercise covering files, paths, streams, readers, writers, NIO.2, and directory operations and serialization risks awareness, object boundaries, and safe data formats; introduce an exception involving threads, executors, futures, locks, atomic types, concurrency collections, and race tests, diagnose it from evidence, apply the smallest reversible correction, and rerun acceptance checks.

1. Confirm scope, prerequisites, identities, dependencies, data, risks, and expected outcome.
2. Perform the course-specific configuration, development, administration, analysis, or business-process workflow.
3. Capture commands, settings, records, logs, screenshots, reports, metrics, or test results.
4. Compare the observed result with acceptance criteria and document corrective or preventive action.

Scenario Analysis

• Identify the technical or business decision and the stakeholders affected by it.
• Compare security, performance, reliability, compliance, cost, usability, and support trade-offs.
• Define rollback, recovery, communication, evidence, ownership, and escalation requirements.

Troubleshooting Guidance

Diagnose issues involving checked and unchecked exceptions, try-with-resources, and custom exceptions, files, paths, streams, readers, writers, NIO.2, and directory operations, serialization risks awareness, object boundaries, and safe data formats, threads, executors, futures, locks, atomic types, concurrency collections, and race tests without making an unverified production change. Separate symptoms from causes, gather time-correlated evidence, test a reversible hypothesis, validate the correction, and record recurrence controls.

Validation Checklist

• The requirement, environment, inputs, dependencies, and expected result are documented.
• The result is reproducible and supported by product-specific evidence.
• Normal, boundary, failure, security, performance, and operational conditions are reviewed.
• Exceptions, rollback, ownership, support actions, and the next improvement priority are recorded.

Lesson Outcome

Learners can apply Exceptions, I/O, NIO.2, Serialization Awareness, Threads, and Concurrency in a realistic Java SE 17: Programming Complete scenario and defend the result with documented evidence.