Java SE 17: Programming Complete — Lesson 2: Generics, Collections, Lambdas, Streams, Optional, and Functional Design

Learning Objectives

• Explain the purpose and operating context of generic classes, methods, bounds, wildcards, type inference, and erasure.
• Apply List, Set, Map, Queue, ordering, hashing, equality, and collection algorithms and functional interfaces, lambdas, method references, and composition in a controlled environment.
• Validate outcomes and troubleshoot risks involving streams, collectors, grouping, reduction, parallel awareness, and Optional.

Detailed Topics

• generic classes, methods, bounds, wildcards, type inference, and erasure
• List, Set, Map, Queue, ordering, hashing, equality, and collection algorithms
• functional interfaces, lambdas, method references, and composition
• streams, collectors, grouping, reduction, parallel awareness, and Optional

Instructor Demonstration

Demonstrate generic classes, methods, bounds, wildcards, type inference, and erasure 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 List, Set, Map, Queue, ordering, hashing, equality, and collection algorithms and functional interfaces, lambdas, method references, and composition; introduce an exception involving streams, collectors, grouping, reduction, parallel awareness, and Optional, 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 generic classes, methods, bounds, wildcards, type inference, and erasure, List, Set, Map, Queue, ordering, hashing, equality, and collection algorithms, functional interfaces, lambdas, method references, and composition, streams, collectors, grouping, reduction, parallel awareness, and Optional 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 Generics, Collections, Lambdas, Streams, Optional, and Functional Design in a realistic Java SE 17: Programming Complete scenario and defend the result with documented evidence.