Skip to content

README.md

Latest commit

 

History

History
120 lines (102 loc) · 6.51 KB

README.md

File metadata and controls

120 lines (102 loc) · 6.51 KB

Campus Course & Records Manager (CCRM)

A console-based Java SE application to manage Students, Courses, Enrollments, Grades, Transcripts, and File Utilities (import/export/backup). Built to demonstrate core Java language features, OOP pillars, Streams, NIO.2, Date/Time API, interfaces, abstract classes, nested classes, enums, lambdas, recursion, and design patterns (Singleton & Builder).

How to Run

  • Prerequisite: JDK 17+ installed and available on PATH
  • Compile:
    • PowerShell:
      • mkdir out
      • javac -d out -encoding UTF-8 $(Get-ChildItem -Recurse src\main\java*.java | ForEach-Object { $_.FullName })
    • CMD:
      • mkdir out
      • for /R %f in (src\main\java*.java) do @set files=%files% "%f"
      • javac -d out -encoding UTF-8 %files%
  • Run:
    • java -cp out edu.ccrm.cli.Main

Minimum Demo Flow

  1. On start, AppConfig (Singleton) loads config and ensures folders (data/export/backup).
  2. CLI switch menu supports: Students, Courses, Enrollment/Grades, Import/Export, Backup & recursive size, Reports, Exit.
  3. Perform enrollments, record grades, print transcript (polymorphism, toString()).
  4. Export and Backup to timestamped folder (NIO.2 Path/Files.walk/copy).
  5. Program prints short platform note (Java SE vs ME vs EE).

Project Structure (packages)

  • edu.ccrm.cli – menu and input loop
  • edu.ccrm.domain – Person (abstract), Student, Instructor, Course (Builder, nested/inner), Enrollment, Grade (enum), Semester (enum), Name (immutable), Transcript (Builder)
  • edu.ccrm.service – StudentService, CourseService, EnrollmentService, TranscriptService (+ in-memory impls)
  • edu.ccrm.io – ImportExportService (CSV), BackupService
  • edu.ccrm.util – Validators, Comparators (lambdas), Recursion utilities, Diamond default-method demo
  • edu.ccrm.config – AppConfig (Singleton), DataStore (Singleton)

Java Concepts Demonstrated

  • OOP pillars: Encapsulation (private fields + getters/setters), Inheritance (Person → Student/Instructor), Abstraction (abstract Person), Polymorphism (base-type refs, overridden toString())
  • Access levels: private/protected/default/public where appropriate
  • Inheritance/constructors: use of super in subclasses
  • Immutability: Name value class with final fields and defensive copying
  • Nested classes: Course has a static nested DepartmentInfo and an inner Roster
  • Interfaces: StudentService et al.; Search/filter using functional interfaces (Predicate); Diamond problem via Alpha/Beta default methods with explicit override
  • Lambdas: Comparators and stream predicates
  • Anonymous inner class: simple callback demo in CLI
  • Enums: Semester, Grade (with fields/constructors and grade points)
  • Advanced: upcast/downcast + instanceof checks (with comments), method overriding & overloading, Builder pattern (Course.Builder, Transcript.Builder), Singleton (AppConfig, DataStore)
  • Exceptions: checked/unchecked, try/catch/multi-catch/finally, throw/throws; custom DuplicateEnrollmentException, MaxCreditLimitExceededException; assertions for invariants
  • File I/O (NIO.2): Path/Files check/delete/copy/move; Streams to process lines; backup via walk/copy; recursive directory size
  • Date/Time API: LocalDate, LocalDateTime for timestamps and folders
  • Core language: primitives/objects, operators, precedence (see comments), decisions (if/else/switch), loops (while/do-while/for/foreach), jump controls (break/continue + one labeled break), arrays & Arrays.sort/binarySearch, Strings (substring/split/join/equals/compareTo)

Evolution of Java (short bullets)

  • 1995: Java 1.0 (Write Once, Run Anywhere)
  • 1998–2006: Java 2 (J2SE/J2EE/J2ME), collections, Swing
  • 2004: Java 5 (generics, enums, annotations)
  • 2011: Java 7 (NIO.2)
  • 2014: Java 8 (lambdas, streams, date/time)
  • 2017+: 9–17 (modules, var, records, pattern matching progress)
  • LTS: 8, 11, 17, 21

Java ME vs SE vs EE (summary)

  • Java ME: Embedded/mobile constrained devices; micro editions and profiles.
  • Java SE: Core standard edition; desktop/CLI apps, core APIs.
  • Java EE/Jakarta EE: Enterprise server-side (JPA, EJB, Servlets, CDI); runs on app servers.

JDK vs JRE vs JVM

  • JVM: Runtime engine executing bytecode (platform-specific implementation)
  • JRE: JVM + standard libraries for running apps (no compilers/tools)
  • JDK: JRE + developer tools (javac, jar, javadoc, etc.)

Interaction: javac compiles source to bytecode -> JVM executes; JDK provides the compiler; JRE/JVM provide runtime.

Windows: Install & Configure Java (steps)

  1. Download JDK 17+ for Windows (x64) from vendor (Oracle, Microsoft, Adoptium).
  2. Install and note path (e.g., C:\Program Files\Java\jdk-17).
  3. Set JAVA_HOME and PATH to include %JAVA_HOME%\bin.
  4. Verify: java -version and javac -version.

Include your screenshots in screenshots/:

  • java -version
  • Eclipse project setup & run
  • Program running (menus)
  • Exports/Backups folder

Using Eclipse IDE

  • File → New → Java Project → Project name: ccrm; set JRE to 17+
  • Add src/main/java to Build Path or configure as source folder
  • Create Run Configuration: Main class = edu.ccrm.cli.Main
  • Run and capture screenshots

Assertions

  • Enable with: java -ea -cp out edu.ccrm.cli.Main
  • Invariants asserted: non-null IDs, credit bounds (1..6), etc.

Usage (CLI quick reference)

  • Import data: choose Import/Export → Import Students/Courses
  • Manage Students/Courses: Add/List/Update/Deactivate
  • Enrollment: Enroll/Unenroll, Record marks, Compute GPA
  • Reports: GPA distribution, Top students
  • Backup: Export then Backup; show recursive size

Mapping: syllabus topic → where

  • Encapsulation → edu.ccrm.domain.* (private fields + getters/setters)
  • Inheritance/Abstraction → Person → Student/Instructor
  • Polymorphism → Transcript printing and service interfaces
  • Singleton → edu.ccrm.config.AppConfig, DataStore
  • Builder → edu.ccrm.domain.Course.Builder, Transcript.Builder
  • Enums → edu.ccrm.domain.Grade/Semester
  • Exceptions → edu.ccrm.service.exceptions.* and try/catch in CLI
  • NIO.2 + Streams → edu.ccrm.io.* (import/export/backup)
  • Recursion → edu.ccrm.util.RecursionUtils
  • Lambdas/Streams → filtering/searching in services and reports
  • Arrays/Arrays.sort → demo in CLI reports
  • Assertions → scattered in domain/service constructors

Screenshots folder

Place your images under screenshots/ with suggested filenames:

  • screenshots/01-java-version.png
  • screenshots/02-eclipse-setup.png
  • screenshots/03-program-running.png
  • screenshots/04-exports-backups-structure.png