ProtoKom

A bare‑bones, thread‑per‑connection Java server–client playground.

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🚀 Quick & Dirty Overview

Imagine you’ve got a rag‑tag bunch of Java classes that stitch together to give you a minimal server–client playground. On the server side you’ve got:

• DataProviders and DataBindings to abstract where your data lives (could be a real DB, could be your imagination).
• A simple Dummy POJO for play‑data.
• A Protocol definition to keep messages consistent.
• ProtoServer that listens for connections and dispatches incoming requests.
• ProtoClient for testing against the server.
• Main to kick everything off.

Meanwhile, tucked in routines/ is a cute little Echo class that shows off how you can plug in new “jobs” or “workers” without touching the server core.

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📦 What’s in the server/ Folder

DataProvider & DataBindings

Think of DataProvider<T> as the interface that defines get, post, update, and delete methods for your data type T. Swap in any storage engine you want (in‑memory, SQL, NoSQL)—just implement this interface.

public interface DataProvider<T> {
  T get(Object id)        throws Exception;
  void post(T entity)     throws Exception;
  void update(T entity)   throws Exception;
  void delete(Object id)  throws Exception;
}

DataBindings<T> is a safety net that makes sure you actually bind a provider before using it—otherwise you’ll hit an IllegalStateException.

public class DataBindings<T> {
  private DataProvider<T> provider;

  public void bindToDataBase(DataProvider<T> p) {
    provider = p;
  }

  private void ensureProvider() {
    if (provider == null)
      throw new IllegalStateException("Bind a DataProvider before using!");
  }

  public T get(Object id) throws Exception {
    ensureProvider();
    return provider.get(id);
  }

  public void post(T entity) throws Exception {
    ensureProvider();
    provider.post(entity);
  }

  public void update(T entity) throws Exception {
    ensureProvider();
    provider.update(entity);
  }

  public void delete(Object id) throws Exception {
    ensureProvider();
    provider.delete(id);
  }
}

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Dummy Data for Fun & Profit

Need a simple object to play with? Enter Dummy.java—just an id and a name:

public class Dummy {
  public int id;
  public String name;

  public Dummy(int id, String name) {
    this.id = id;
    this.name = name;
  }
}

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Protocol: The Contract

In Protocol.java you define the shapes of your request/response objects (enums, message classes, etc.). This is where both server and client agree on the “language” you’re speaking—no more magic strings.

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ProtoServer & Friends

• ProtoServer.java Listens on a TCP port, spawns a new thread per connection, reads incoming messages, and routes them to your data bindings or routines.

• ProtoClient.java A simple socket‑based client to send Protocol messages to your server and print the replies.

• Main.java Your entry point. Boots the server, binds a sample Dummy provider, maybe spins up a demo client, and ties all the pieces together.

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🔄 The routines/ Folder

Echo Routine

Want to add a new routine? Check out routines/Echo.java:

package routines;

public class Echo {
  private static final String DEFAULT_NAME = "Echo";
  private String name;

  public Echo(String name) {
    this.name = name;
  }

  public Echo() {
    this.name = DEFAULT_NAME;
  }

  public String echo(String message) {
    String formatted = "[ " + name + " ]: " + message;
    log(message);
    return formatted;
  }

  public void log(String message) {
    System.out.println("[ " + name + " ]: " + message);
  }

  public String log_err_with_ret(Exception e) {
    String formatted = "[ " + name + " ]: " + e.getMessage();
    System.err.println(formatted);
    return formatted;
  }
}

Drop your own routines into this folder—just instantiate and call them from your server routing logic.

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🏃 Running It

1. Compile everything

   javac *.java routines/*.java

2. Start the server

   java Main

3. (Optional) Launch ProtoClient in another shell to chat with your server.

Or you could legit just

java Main.java

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🤔 Next Steps

• Swap out the Dummy + DataBindings combo for a real database driver.
• Define new routines in routines/ (e.g. Calculator, WeatherFetcher).
• Enhance Protocol.java to support richer formats (JSON, Protobuf, etc.).
• Add authentication, robust error handling, and graceful shutdown hooks.

Enjoy hacking on this rag‑tag server–client model! 🚀