UpdateHealthPacket

protocol/src/main/java/mc/protocol/State.java

@@ -60,6 +60,7 @@ public enum State {
 					JoinGamePacket.class, 0x23,
 					PlayerAbilitiesPacket.class,0x2C,
 					SPlayerPositionAndLookPacket.class, 0x2F,
+					UpdateHealthPacket.class, 0x41,
 					SpawnPositionPacket.class, 0x46
 			)
 	);

protocol/src/main/java/mc/protocol/packets/server/UpdateHealthPacket.java

@@ -0,0 +1,35 @@
+package mc.protocol.packets.server;
+
+import lombok.Data;
+import mc.protocol.io.NetByteBuf;
+import mc.protocol.packets.ServerSidePacket;
+
+/**
+ * Update Health Packet.
+ *
+ * <p>Структура пакета</p>
+ * <pre>
+ * | FIELD           | TYPE   | NOTES                            |
+ * |-----------------|--------|----------------------------------|
+ * | Health          | Float  | 0 = смерть; 20 = полное здоровье |
+ * | Food            | VarInt | 0-20                             |
+ * | Food Saturation | Float  | 0-5                              |
+ * </pre>
+ *
+ * @see <a href="https://wiki.vg/index.php?title=Protocol&oldid=14204#Update_Health">Update Health</a>
+ * @see <a href="https://minecraft.fandom.com/wiki/Food#Hunger_and_saturation">Food: Hunger and saturation</a>
+ */
+@Data
+public class UpdateHealthPacket implements ServerSidePacket {
+
+	private float health;
+	private int food;
+	private float foodSaturation;
+
+	@Override
+	public void writeSelf(NetByteBuf netByteBuf) {
+		netByteBuf.writeFloat(this.health);
+		netByteBuf.writeVarInt(this.food);
+		netByteBuf.writeFloat(this.foodSaturation);
+	}
+}

server/src/main/java/mc/server/PacketHandler.java

@@ -26,6 +26,7 @@ import java.util.Base64;
 import java.util.Collections;
 import java.util.Random;
 import java.util.UUID;
+import java.util.concurrent.TimeUnit;
 
 @Slf4j
 @RequiredArgsConstructor
@@ -67,6 +68,7 @@ public class PacketHandler {
 		context.sendNow(response);
 	}
 
+	@SuppressWarnings("java:S2189")
 	public void onLoginStart(ConnectionContext context, LoginStartPacket loginStartPacket) {
 		var loginSuccessPacket = new LoginSuccessPacket();
 		loginSuccessPacket.setUuid(UUID.randomUUID());
@@ -122,6 +124,32 @@ public class PacketHandler {
 		context.send(pingPacket);
 
 		context.flushSending();
+
+		// -- Эксперименты -- //
+
+		var updateHealthPacket = new UpdateHealthPacket();
+		updateHealthPacket.setHealth(0.1f);
+		updateHealthPacket.setFood(0);
+		updateHealthPacket.setFoodSaturation(5.0f);
+
+		context.sendNow(updateHealthPacket);
+
+		while (true) {
+			context.sendNow(updateHealthPacket);
+
+			updateHealthPacket.setHealth(updateHealthPacket.getHealth() + 1.0f);
+			updateHealthPacket.setFood(updateHealthPacket.getFood() + 1);
+			if (updateHealthPacket.getHealth() > 20.0f) {
+				updateHealthPacket.setHealth(0.1f);
+				updateHealthPacket.setFood(0);
+			}
+
+			try {
+				TimeUnit.MILLISECONDS.sleep(50);
+			} catch (InterruptedException e) {
+				break;
+			}
+		}
 	}
 
 	private static String faviconToBase64(Path iconPath) {