03. జావా సింటాక్స్, క్లాస్ స్ట్రక్చర్ & main() అనాటమీ (Java Syntax, Class Structure & main() Anatomy)

public class CommandLineParser {
    public static void main(String[] args) {
        System.out.println("==================================================");
        System.out.println("      COMMAND LINE ARGUMENTS PROCESSOR ENGINE     ");
        System.out.println("==================================================");

        // Checking if user supplied arguments
        if (args.length == 0) {
            System.out.println("[INFO] No external CLI arguments detected.");
            System.out.println("[INFO] Defaulting to demo developer credentials:");
            String defaultUser = "Kiran Kumar";
            String defaultRole = "FullStack Java Engineer";
            System.out.printf("  User : %s%n  Role : %s%n", defaultUser, defaultRole);
        } else {
            System.out.println("[SUCCESS] Received " + args.length + " argument(s) from Terminal:");
            for (int i = 0; i < args.length; i++) {
                System.out.printf("  Arg [%d]: %s%n", i, args[i]);
            }
        }

        System.out.println("--------------------------------------------------");
        System.out.println("Status: CLI Processing Completed Flawlessly!");
        System.out.println("==================================================");
    }
}

// Main public class - Must match the file name: MultiClassDemo.java
public class MultiClassDemo {
    public static void main(String[] args) {
        System.out.println("--------------------------------------------------");
        System.out.println("      MULTI-CLASS COMPILATION DEMO ENGINE         ");
        System.out.println("--------------------------------------------------");

        // Using helper classes defined in the same source file
        ServerTelemetry telemetry = new ServerTelemetry("Cluster-AP-South-1", "ACTIVE");
        telemetry.displayStatus();

        AuditLogger.logEvent("MultiClassDemo executed successfully.");
        System.out.println("--------------------------------------------------");
    }
}

// Non-public helper class 1
class ServerTelemetry {
    private String serverId;
    private String status;

    public ServerTelemetry(String serverId, String status) {
        this.serverId = serverId;
        this.status = status;
    }

    public void displayStatus() {
        System.out.println("  [SERVER ID] " + serverId);
        System.out.println("  [STATUS]    " + status);
    }
}

// Non-public helper class 2
class AuditLogger {
    public static void logEvent(String message) {
        System.out.println("  [AUDIT LOG] " + message);
    }
}

public class SyntaxInspectorCapstone {
    public static void main(String[] args) {
        String developerName = "నవీన్ చంద్ర";
        String trackName      = "Enterprise Java 21+ Masterclass";
        int chapterNum        = 3;
        int totalChapters     = 25;
        boolean isSyntaxValid = true;

        System.out.println("==================================================");
        System.out.println("      JAVA 21 SYNTAX INSPECTION & REPORT         ");
        System.out.println("==================================================");

        // Printing formatted diagnostics
        System.out.printf("  [DEVELOPER] %s%n", developerName);
        System.out.printf("  [CURRICULUM] %s%n", trackName);
        System.out.printf("  [MODULE]    Chapter %02d of %02d%n", chapterNum, totalChapters);
        System.out.printf("  [STATUS]    Class Structure: %s%n", isSyntaxValid ? "VERIFIED (100% OK)" : "INVALID");
        System.out.println("--------------------------------------------------");

        // Multi-line Text Block documentation
        String summary = """
            [SYNTAX VERIFICATION REPORT]
            • Public Class Name Matches File: YES
            • Main Method Signature Valid  : YES
            • Statement Semicolons Checked  : YES
            • Code Block Scopes Balanced   : YES
            """;

        System.out.println(summary.trim());
        System.out.println("==================================================");
    }
}