initial commit

aeron/subscriber/Subscriber.java

@@ -0,0 +1,65 @@
+import io.aeron.Aeron;
+import io.aeron.Subscription;
+import io.aeron.Image;
+import io.aeron.driver.MediaDriver;
+import io.aeron.logbuffer.FragmentHandler;
+import org.agrona.DirectBuffer;
+import org.agrona.concurrent.BackoffIdleStrategy;
+import org.agrona.concurrent.IdleStrategy;
+
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class Subscriber {
+
+  public static void main(String[] args) {
+    final AtomicBoolean running = new AtomicBoolean(true);
+
+    MediaDriver driver = MediaDriver.launchEmbedded();
+
+    Aeron.Context ctx = new Aeron.Context()
+        .availableImageHandler((Image img) -> System.out.println("Publisher available: " + img.sourceIdentity()))
+        .unavailableImageHandler((Image img) -> System.out.println("Publisher gone: " + img.sourceIdentity()))
+        .aeronDirectoryName(driver.aeronDirectoryName());
+
+    Aeron aeron = Aeron.connect(ctx);
+
+    String channel = "aeron:udp?endpoint=0.0.0.0:40123";
+    int streamId = 1001;
+
+    Subscription sub = aeron.addSubscription(channel, streamId);
+    IdleStrategy idleStrategy = new BackoffIdleStrategy(1, 1, 1, 1);
+
+    System.out.println("Subscriber ready, waiting for messages...");
+
+    // Fragment handler
+    FragmentHandler handler = (DirectBuffer buffer, int offset, int length, io.aeron.logbuffer.Header header) -> {
+      String msg = buffer.getStringWithoutLengthUtf8(offset, length).trim();
+      System.out.println("RAW MESSAGE: '" + msg + "'");
+
+      String[] parts = msg.split(",");
+      if (parts.length == 2) {
+        try {
+          long counter = Long.parseLong(parts[0].trim());
+          long sendTime = Long.parseLong(parts[1].trim());
+          long latency = System.currentTimeMillis() - sendTime;
+
+          System.out.printf("Received: %d | Latency: %d ms%n", counter, latency);
+        } catch (NumberFormatException e) {
+          System.err.println("Failed to parse message: " + msg);
+        }
+      } else {
+        System.err.println("Malformed message: " + msg);
+      }
+    };
+
+    while (running.get()) {
+      int fragments = sub.poll(handler, 10);
+      idleStrategy.idle(fragments);
+    }
+
+    sub.close();
+    aeron.close();
+    driver.close();
+  }
+}