Add Java advanced project

Author: lucasbellesi

CONCEPT_INDEX.md

@@ -60,7 +60,7 @@ Use this page to browse the same concept across every active language track.
 | --- | --- | --- | --- | --- | --- | --- |
 | 01-foundations | [C++](languages/cpp/projects/01-foundations/README.md) | [C#](languages/csharp/projects/01-foundations/README.md) | [Go](languages/go/projects/01-foundations/README.md) | [Java](languages/java/projects/01-foundations/README.md) | [Python](languages/python/projects/01-foundations/README.md) | [TypeScript](languages/typescript/projects/01-foundations/README.md) |
 | 02-core | [C++](languages/cpp/projects/02-core/README.md) | [C#](languages/csharp/projects/02-core/README.md) | [Go](languages/go/projects/02-core/README.md) | [Java](languages/java/projects/02-core/README.md) | [Python](languages/python/projects/02-core/README.md) | [TypeScript](languages/typescript/projects/02-core/README.md) |
-| 03-advanced | [C++](languages/cpp/projects/03-advanced/README.md) | [C#](languages/csharp/projects/03-advanced/README.md) | [Go](languages/go/projects/03-advanced/README.md) | Planned | [Python](languages/python/projects/03-advanced/README.md) | [TypeScript](languages/typescript/projects/03-advanced/README.md) |
+| 03-advanced | [C++](languages/cpp/projects/03-advanced/README.md) | [C#](languages/csharp/projects/03-advanced/README.md) | [Go](languages/go/projects/03-advanced/README.md) | [Java](languages/java/projects/03-advanced/README.md) | [Python](languages/python/projects/03-advanced/README.md) | [TypeScript](languages/typescript/projects/03-advanced/README.md) |
 | 04-expert | [C++](languages/cpp/projects/04-expert/README.md) | [C#](languages/csharp/projects/04-expert/README.md) | [Go](languages/go/projects/04-expert/README.md) | Planned | [Python](languages/python/projects/04-expert/README.md) | [TypeScript](languages/typescript/projects/04-expert/README.md) |
 
 ### Assessments

LANGUAGE_PARITY_MATRIX.md

@@ -86,7 +86,7 @@ Status labels:
 | --- | --- | --- | --- | --- | --- | --- |
 | 01-foundations | Done | Done | Done | Done | Done | Done |
 | 02-core | Done | Done | Done | Done | Done | Done |
-| 03-advanced | Done | Done | Done | Planned | Done | Done |
+| 03-advanced | Done | Done | Done | Done | Done | Done |
 | 04-expert | Done | Done | Done | Planned | Done | Done |
 
 ### Assessments

README.md

@@ -56,7 +56,7 @@ If you only want to learn one track, follow that track README first because lang
 | C++ | 00-setup, 01-foundations, 02-core, 03-advanced, 04-expert | Foundations, Core, Advanced, Expert, projects, assessments | Most complete and primary track |
 | C# | 01-foundations, 02-core, 03-advanced, 04-expert | 8/8 foundations modules, 6/6 core modules, 5/5 advanced modules, 5/5 expert modules, 4/4 projects, 4/4 assessments | Module and checkpoint parity complete through expert |
 | Go | 01-foundations, 02-core, 03-advanced, 04-expert | 8/8 foundations modules, 6/6 core modules, 5/5 advanced modules, 5/5 expert modules, 4/4 projects, 4/4 assessments | Module and checkpoint parity complete through expert |
-| Java | 01-foundations, 02-core, 03-advanced | 8/8 foundations modules, 6/6 core modules, 5/5 advanced modules, 2/4 projects, 2/4 assessments | Java 21 MVP through advanced modules; advanced checkpoints, expert, and later checkpoints planned |
+| Java | 01-foundations, 02-core, 03-advanced | 8/8 foundations modules, 6/6 core modules, 5/5 advanced modules, 3/4 projects, 2/4 assessments | Java 21 MVP through advanced modules and projects; advanced assessment, expert, and later checkpoints planned |
 | Python | 01-foundations, 02-core, 03-advanced, 04-expert | 8/8 foundations modules, 6/6 core modules, 5/5 advanced modules, 5/5 expert modules, 4/4 projects, 4/4 assessments | Module and checkpoint parity complete through expert |
 | TypeScript | 01-foundations, 02-core, 03-advanced, 04-expert | 8/8 foundations modules, 6/6 core modules, 5/5 advanced modules, 5/5 expert modules, 4/4 projects, 4/4 assessments | Module and checkpoint parity complete through expert |
 

languages/java/CHECKLIST.md

@@ -38,6 +38,7 @@
 
 - [ ] projects/01-foundations
 - [ ] projects/02-core
+- [ ] projects/03-advanced
 - [ ] assessments/01-foundations
 - [ ] assessments/02-core
 
@@ -57,7 +58,6 @@
 ## Planned
 
 - [ ] 04-expert modules
-- [ ] projects/03-advanced
 - [ ] projects/04-expert
 - [ ] assessments/03-advanced
 - [ ] assessments/04-expert

languages/java/README.md

@@ -2,13 +2,13 @@
 
 ## Scope and Status
 
-This track currently covers `01-foundations`, `02-core`, and `03-advanced` as a Java 21 MVP, including projects and assessments for the first two implemented levels. Expert modules and later checkpoints are planned for future iterations.
+This track currently covers `01-foundations`, `02-core`, and `03-advanced` as a Java 21 MVP, including projects through `03-advanced` and assessments through `02-core`. Expert modules and later checkpoints are planned for future iterations.
 
 - 8/8 foundations modules implemented.
 - 6/6 core modules implemented.
 - 5/5 advanced modules implemented (`structs-and-classes`, `constructors-and-invariants`, `copy-and-move-semantics`, `inheritance-and-polymorphism`, `templates-basics`).
 - 0/5 expert modules implemented.
-- 2/4 projects implemented (`01-foundations`, `02-core`).
+- 3/4 projects implemented (`01-foundations`, `02-core`, `03-advanced`).
 - 2/4 assessments implemented (`01-foundations`, `02-core`).
 - Uses Java 21 LTS with direct `javac` and `java` commands; no Maven or Gradle yet.
 
@@ -58,6 +58,7 @@ java -cp build/java Main
 - Projects
   - [01-foundations](./projects/01-foundations/README.md)
   - [02-core](./projects/02-core/README.md)
+  - [03-advanced](./projects/03-advanced/README.md)
 - Assessments
   - [01-foundations](./assessments/01-foundations/README.md)
   - [02-core](./assessments/02-core/README.md)

languages/java/projects/03-advanced/Main.java

@@ -0,0 +1,112 @@
+import java.util.ArrayList;
+import java.util.List;
+
+public class Main {
+    interface Reportable {
+        String reportLine();
+    }
+
+    record Student(String id, String name) {
+        Student {
+            if (id == null || id.isBlank()) {
+                throw new IllegalArgumentException("id must not be blank");
+            }
+            if (name == null || name.isBlank()) {
+                throw new IllegalArgumentException("name must not be blank");
+            }
+        }
+    }
+
+    static final class Course implements Reportable {
+        private final String title;
+        private final int capacity;
+        private final List<Student> enrolled = new ArrayList<>();
+
+        Course(String title, int capacity) {
+            if (title == null || title.isBlank()) {
+                throw new IllegalArgumentException("title must not be blank");
+            }
+            if (capacity < 0) {
+                throw new IllegalArgumentException("capacity must not be negative");
+            }
+            this.title = title;
+            this.capacity = capacity;
+        }
+
+        boolean enroll(Student student) {
+            if (enrolled.size() >= capacity || hasStudent(student.id())) {
+                return false;
+            }
+            enrolled.add(student);
+            return true;
+        }
+
+        boolean dropById(String studentId) {
+            return enrolled.removeIf(student -> student.id().equals(studentId));
+        }
+
+        List<Student> rosterSnapshot() {
+            return List.copyOf(enrolled);
+        }
+
+        @Override
+        public String reportLine() {
+            return "Course: " + title + " | " + enrolled.size() + "/" + capacity + " enrolled";
+        }
+
+        private boolean hasStudent(String studentId) {
+            for (Student student : enrolled) {
+                if (student.id().equals(studentId)) {
+                    return true;
+                }
+            }
+            return false;
+        }
+    }
+
+    static final class Catalog<T extends Reportable> {
+        private final List<T> items;
+
+        Catalog(List<T> items) {
+            this.items = new ArrayList<>(items);
+        }
+
+        List<T> snapshot() {
+            return List.copyOf(items);
+        }
+    }
+
+    static <T extends Reportable> void printReport(String title, List<T> items) {
+        System.out.println(title);
+        for (T item : items) {
+            System.out.println(item.reportLine());
+        }
+    }
+
+    public static void main(String[] args) {
+        Student ana = new Student("S-101", "Ana Smith");
+        Student bob = new Student("S-202", "Bob Lee");
+        Student carla = new Student("S-303", "Carla Mendez");
+
+        Course javaAdvanced = new Course("JavaAdvanced", 2);
+        Course algorithms = new Course("Algorithms", 3);
+
+        javaAdvanced.enroll(ana);
+        javaAdvanced.enroll(bob);
+        boolean overflowAccepted = javaAdvanced.enroll(carla);
+
+        algorithms.enroll(carla);
+        algorithms.dropById("S-404");
+
+        List<Course> externalCourses = new ArrayList<>();
+        externalCourses.add(javaAdvanced);
+        externalCourses.add(algorithms);
+        Catalog<Course> catalog = new Catalog<>(externalCourses);
+        externalCourses.clear();
+
+        printReport("Course Enrollment Report", catalog.snapshot());
+        System.out.println("Overflow accepted: " + overflowAccepted);
+        System.out.println("Catalog courses after external clear: " + catalog.snapshot().size());
+        System.out.println("JavaAdvanced roster snapshot: " + javaAdvanced.rosterSnapshot().size());
+    }
+}

languages/java/projects/03-advanced/README.md

@@ -0,0 +1,65 @@
+# 03 Advanced Capstone: Course Enrollment Manager
+
+## Goal
+
+Model courses and enrollments with Java classes, invariants, defensive copies, polymorphic reporting, and generic helpers.
+
+## Learning Metadata
+
+- Difficulty: Intermediate.
+- Estimated Time: 60-90 minutes.
+- Prerequisites: All `03-advanced` modules, especially `constructors-and-invariants`, `copy-and-move-semantics`, `inheritance-and-polymorphism`, and `templates-basics`.
+- Learning Focus: Integrate custom types, guarded state changes, copy boundaries, and reusable reporting in one small object-oriented program.
+
+## Quick Run
+
+```bash
+javac -d build/java languages/java/projects/03-advanced/Main.java
+java -cp build/java Main
+```
+
+## Requirements
+
+- Define a `Student` record with validated fields.
+- Define a `Course` class with title, capacity, enroll, drop, and status behavior.
+- Prevent enrollment beyond capacity and duplicate student IDs.
+- Return immutable snapshots instead of internal mutable lists.
+- Print multiple reportable objects through one generic helper.
+
+## Concepts Practiced
+
+- Records and classes.
+- Constructor-enforced invariants.
+- Defensive copies with `List.copyOf`.
+- Interfaces and polymorphic reporting.
+- Generic methods and generic containers.
+
+## Sample Output
+
+```text
+Course Enrollment Report
+Course: JavaAdvanced | 2/2 enrolled
+Course: Algorithms | 1/3 enrolled
+Overflow accepted: false
+Catalog courses after external clear: 2
+JavaAdvanced roster snapshot: 2
+```
+
+## Cross-Language Notes
+
+- Compared with C++, Java uses references and defensive copies instead of explicit move constructors.
+- Relative to Python, Java makes the model boundaries more verbose but more compile-time checked.
+- Compared with TypeScript, Java uses nominal interfaces and JVM collection APIs for snapshots.
+
+## What To Check
+
+- course capacity and duplicate student rules are enforced
+- external list changes do not mutate the catalog
+- report output reflects the final object state
+- generic reporting works for more than one concrete object
+
+## Extension Ideas
+
+- Add waitlist behavior.
+- Read enrollment commands from a file.
+- Add grade summaries per course.

scripts/automation_manifest.json

@@ -138,7 +138,7 @@
         ]
       },
       "checkpoints": {
-        "projects": ["01-foundations", "02-core"],
+        "projects": ["01-foundations", "02-core", "03-advanced"],
         "assessments": ["01-foundations", "02-core"]
       },
       "checkpoint_main": "Main.java",
@@ -149,15 +149,15 @@
       },
       "track_readme": "languages/java/README.md",
       "track_readme_markers": [
-        "This track currently covers `01-foundations`, `02-core`, and `03-advanced` as a Java 21 MVP, including projects and assessments for the first two implemented levels. Expert modules and later checkpoints are planned for future iterations.",
+        "This track currently covers `01-foundations`, `02-core`, and `03-advanced` as a Java 21 MVP, including projects through `03-advanced` and assessments through `02-core`. Expert modules and later checkpoints are planned for future iterations.",
         "- 8/8 foundations modules implemented.",
         "- 6/6 core modules implemented.",
         "- 5/5 advanced modules implemented (`structs-and-classes`, `constructors-and-invariants`, `copy-and-move-semantics`, `inheritance-and-polymorphism`, `templates-basics`).",
-        "- 2/4 projects implemented (`01-foundations`, `02-core`).",
+        "- 3/4 projects implemented (`01-foundations`, `02-core`, `03-advanced`).",
         "- 2/4 assessments implemented (`01-foundations`, `02-core`).",
         "- Uses Java 21 LTS with direct `javac` and `java` commands; no Maven or Gradle yet."
       ],
-      "root_status_row": "| Java | 01-foundations, 02-core, 03-advanced | 8/8 foundations modules, 6/6 core modules, 5/5 advanced modules, 2/4 projects, 2/4 assessments | Java 21 MVP through advanced modules; advanced checkpoints, expert, and later checkpoints planned |"
+      "root_status_row": "| Java | 01-foundations, 02-core, 03-advanced | 8/8 foundations modules, 6/6 core modules, 5/5 advanced modules, 3/4 projects, 2/4 assessments | Java 21 MVP through advanced modules and projects; advanced assessment, expert, and later checkpoints planned |"
     },
     "python": {
       "extension": "py",
@@ -227,7 +227,7 @@
         "| types-and-io | Done | Done | Done | Done | Done | Done |",
         "| 02-core | Done | Done | Done | Done | Done | Done |",
         "| 1 | input-validation | Done | Done | Done | Done | Done | Done |",
-        "| 03-advanced | Done | Done | Done | Planned | Done | Done |",
+        "| 03-advanced | Done | Done | Done | Done | Done | Done |",
         "| 04-expert | Done | Done | Done | Planned | Done | Done |"
       ]
     }
@@ -915,6 +915,17 @@
             }
           ],
           "cleanup_paths": ["core_assessment_report.txt"]
+        },
+        {
+          "program": "languages/java/projects/03-advanced/Main.java",
+          "required_stdout_contains": [
+            "Course Enrollment Report",
+            "Course: JavaAdvanced | 2/2 enrolled",
+            "Course: Algorithms | 1/3 enrolled",
+            "Overflow accepted: false",
+            "Catalog courses after external clear: 2",
+            "JavaAdvanced roster snapshot: 2"
+          ]
         }
       ]
     }