An easy-to-use, event-driven, asynchronous, network application framework. SimpleNet provides a built-in Server class which the user can instantiate and bind to an existing IP address and port. The user can then create one or more Client instances and connect to their Server using the same IP address and port.

1. Add SimpleNet as a dependency using either Maven or Gradle:

Maven:

<dependency>
    <groupId>com.github.jhg023</groupId>
    <artifactId>SimpleNet</artifactId>
    <version>1.4.2</version>
</dependency>

Gradle:

compile 'com.github.jhg023:SimpleNet:1.4.2'

2. Because SimpleNet is compiled with Java 11, you must first require its module in your module-info.java:

module my.project {
    requires SimpleNet;
}

3. To create a Client, you can use the following:

// Instantiate a new Client.
var client = new Client();

// Register a connection listener.
client.onConnect(() -> {
    System.out.println(client + " has connected to the server!");
    
    // Builds a packet and sends it to the server immediately.
    Packet.builder().putByte(1).putInt(42).writeAndFlush(client);
});

// Register an optional pre-disconnection listener.
client.preDisconnect(() -> System.out.println(client + " is about to disconnect from the server!"));

// Register an optional post-disconnection listener.
client.postDisconnect(() -> System.out.println(client + " successfully disconnected from the server!"));

// Attempt to connect to a server AFTER registering listeners.
client.connect("localhost", 43594);

4. To create a Server, you can use the following:

// Instantiate a new Server.
var server = new Server();

// Register one connection listener.
server.onConnect(client -> {
    System.out.println(client + " has connected!");

    /*
     * When one byte arrives from the client, switch on it.
     * If the byte equals 1, then print an int when it arrives.
     *
     * Because `readByteAlways` is used, this will loop when
     * the callback completes, but does not hang the main thread.
     */
    client.readByteAlways(opcode -> {
        switch (opcode) {
            case 1:
                client.readInt(System.out::println);
        }
    });

    // Register an optional pre-disconnection listener.
    client.preDisconnect(() -> System.out.println(client + " is about to disconnect!"));

    // Register an optional post-disconnection listener.
    client.postDisconnect(() -> System.out.println(client + " has successfully disconnected!"));
});

// Bind the server to an address and port AFTER registering listeners.
server.bind("localhost", 43594);

5. Congratulations, you're finished!

• Can data be sent and received outside of the onConnect callback?
  • Yes, but only if the client is already connected to the server. However, this is not recommended unless you're well-versed in concurrency, as the onConnect callback is performed asynchronously.
• Can a SimpleNet Client be used with some unrelated server and vice-versa?
  • Absolutely!
• I have large packets that exceed the default buffer size; what can I do to avoid an exception?
  • Ideally, the best option would be to split your single, large packet into multiple, small packets.
  • If splitting the packet is not possible for any reason, both Client and Server have an overloaded constructor that accepts a buffer size in bytes. You can simply specify a size larger than 4096 (the default size).
• Will Java 8 ever be supported again?
  • No, as Java 8 is approaching its EOL (January, 2019). SimpleNet will do its best to keep up with LTS releases.
• What's next for SimpleNet?
  • Once Project Loom is complete and integrated into the mainline JDK, SimpleNet will be rewritten entirely; blocking I/O will be using fibers at that point, which will be much more scalable than my current implementation that uses a thread pool.