Add some inline packet initialization

src/main/java/net/minestom/server/entity/Player.java

@@ -1379,9 +1379,7 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
      * @param entity the entity to spectate
      */
     public void spectate(@NotNull Entity entity) {
-        CameraPacket cameraPacket = new CameraPacket();
+        playerConnection.sendPacket(new CameraPacket(entity));
-        cameraPacket.cameraId = entity.getEntityId();
-        playerConnection.sendPacket(cameraPacket);
     }
 
     /**

src/main/java/net/minestom/server/instance/InstanceContainer.java

@@ -750,10 +750,7 @@ public class InstanceContainer extends Instance {
      * @param blockStateId  the new state of the block
      */
     private void sendBlockChange(@NotNull Chunk chunk, @NotNull BlockPosition blockPosition, short blockStateId) {
-        BlockChangePacket blockChangePacket = new BlockChangePacket();
+        chunk.sendPacketToViewers(new BlockChangePacket(blockPosition, blockStateId));
-        blockChangePacket.blockPosition = blockPosition;
-        blockChangePacket.blockStateId = blockStateId;
-        chunk.sendPacketToViewers(blockChangePacket);
     }
 
     @Override

src/main/java/net/minestom/server/listener/BlockPlacementListener.java

@@ -104,10 +104,7 @@ public class BlockPlacementListener {
                 //Send a block change with AIR as block to keep the client in sync,
                 //using refreshChunk results in the client not being in sync
                 //after rapid invalid block placements
-                BlockChangePacket blockChangePacket = new BlockChangePacket();
+                player.getPlayerConnection().sendPacket(new BlockChangePacket(blockPosition, Block.AIR.getBlockId()));
-                blockChangePacket.blockPosition = blockPosition;
-                blockChangePacket.blockStateId = Block.AIR.getBlockId();
-                player.getPlayerConnection().sendPacket(blockChangePacket);
             }
             return;
         }

src/main/java/net/minestom/server/listener/PlayerDiggingListener.java

@@ -263,13 +263,6 @@ public class PlayerDiggingListener {
      */
     private static void sendAcknowledgePacket(@NotNull Player player, @NotNull BlockPosition blockPosition, int blockStateId,
                                               @NotNull ClientPlayerDiggingPacket.Status status, boolean success) {
-        AcknowledgePlayerDiggingPacket acknowledgePlayerDiggingPacket = new AcknowledgePlayerDiggingPacket();
+        player.getPlayerConnection().sendPacket(new AcknowledgePlayerDiggingPacket(blockPosition, blockStateId, status, success));
-        acknowledgePlayerDiggingPacket.blockPosition = blockPosition;
-        acknowledgePlayerDiggingPacket.blockStateId = blockStateId;
-        acknowledgePlayerDiggingPacket.status = status;
-        acknowledgePlayerDiggingPacket.successful = success;
-
-        player.getPlayerConnection().sendPacket(acknowledgePlayerDiggingPacket);
     }
-
 }

src/main/java/net/minestom/server/network/packet/server/play/AcknowledgePlayerDiggingPacket.java

@@ -10,12 +10,22 @@ import org.jetbrains.annotations.NotNull;
 
 public class AcknowledgePlayerDiggingPacket implements ServerPacket {
 
-    public BlockPosition blockPosition = new BlockPosition(0,0,0);
+    public BlockPosition blockPosition;
     public int blockStateId;
-    public ClientPlayerDiggingPacket.Status status = ClientPlayerDiggingPacket.Status.STARTED_DIGGING;
+    public ClientPlayerDiggingPacket.Status status;
     public boolean successful;
 
-    public AcknowledgePlayerDiggingPacket() {}
+    public AcknowledgePlayerDiggingPacket(@NotNull BlockPosition blockPosition, int blockStateId,
+                                          @NotNull ClientPlayerDiggingPacket.Status status, boolean success) {
+        this.blockPosition = blockPosition;
+        this.blockStateId = blockStateId;
+        this.status = status;
+        this.successful = success;
+    }
+
+    public AcknowledgePlayerDiggingPacket() {
+        this(new BlockPosition(0, 0, 0), 0, ClientPlayerDiggingPacket.Status.STARTED_DIGGING, false);
+    }
 
     @Override
     public void write(@NotNull BinaryWriter writer) {

src/main/java/net/minestom/server/network/packet/server/play/ActionBarPacket.java

@@ -9,13 +9,14 @@ import org.jetbrains.annotations.NotNull;
 
 public class ActionBarPacket implements ServerPacket {
 
-    public Component actionBarText = Component.empty();
+    public Component actionBarText;
 
-    public ActionBarPacket() {
+    public ActionBarPacket(@NotNull Component actionBarText) {
+        this.actionBarText = actionBarText;
     }
 
-    public ActionBarPacket(Component actionBarText) {
+    public ActionBarPacket() {
-        this.actionBarText = actionBarText;
+        this(Component.empty());
     }
 
     @Override

src/main/java/net/minestom/server/network/packet/server/play/AttachEntityPacket.java

@@ -1,17 +1,30 @@
 package net.minestom.server.network.packet.server.play;
 
+import net.minestom.server.entity.Entity;
 import net.minestom.server.network.packet.server.ServerPacket;
 import net.minestom.server.network.packet.server.ServerPacketIdentifier;
 import net.minestom.server.utils.binary.BinaryReader;
 import net.minestom.server.utils.binary.BinaryWriter;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class AttachEntityPacket implements ServerPacket {
 
     public int attachedEntityId;
     public int holdingEntityId; // Or -1 to detach
 
-    public AttachEntityPacket() {}
+    public AttachEntityPacket(int attachedEntityId, int holdingEntityId) {
+        this.attachedEntityId = attachedEntityId;
+        this.holdingEntityId = holdingEntityId;
+    }
+
+    public AttachEntityPacket(@NotNull Entity attachedEntity, @Nullable Entity holdingEntity) {
+        this(attachedEntity.getEntityId(), holdingEntity != null ? holdingEntity.getEntityId() : -1);
+    }
+
+    public AttachEntityPacket() {
+        this(0, 0);
+    }
 
     @Override
     public void write(@NotNull BinaryWriter writer) {

src/main/java/net/minestom/server/network/packet/server/play/BlockChangePacket.java

@@ -12,8 +12,13 @@ public class BlockChangePacket implements ServerPacket {
     public BlockPosition blockPosition;
     public int blockStateId;
 
+    public BlockChangePacket(BlockPosition blockPosition, int blockStateId) {
+        this.blockPosition = blockPosition;
+        this.blockStateId = blockStateId;
+    }
+
     public BlockChangePacket() {
-        blockPosition = new BlockPosition(0,0,0);
+        this(new BlockPosition(0, 0, 0), 0);
     }
 
     @Override

src/main/java/net/minestom/server/network/packet/server/play/CameraPacket.java

@@ -1,5 +1,6 @@
 package net.minestom.server.network.packet.server.play;
 
+import net.minestom.server.entity.Entity;
 import net.minestom.server.network.packet.server.ServerPacket;
 import net.minestom.server.network.packet.server.ServerPacketIdentifier;
 import net.minestom.server.utils.binary.BinaryReader;
@@ -10,7 +11,17 @@ public class CameraPacket implements ServerPacket {
 
     public int cameraId;
 
-    public CameraPacket() {}
+    public CameraPacket(int cameraId) {
+        this.cameraId = cameraId;
+    }
+
+    public CameraPacket(@NotNull Entity camera) {
+        this(camera.getEntityId());
+    }
+
+    public CameraPacket() {
+        this(0);
+    }
 
     @Override
     public void write(@NotNull BinaryWriter writer) {

src/main/java/net/minestom/server/network/packet/server/play/ChatMessagePacket.java

@@ -26,18 +26,16 @@ public class ChatMessagePacket implements ComponentHoldingServerPacket {
     public ChatPosition position;
     public UUID uuid;
 
-    public ChatMessagePacket() {
-        this.message = Component.empty();
-        this.position = ChatPosition.SYSTEM_MESSAGE;
-        this.uuid = NULL_UUID;
-    }
-
     public ChatMessagePacket(@NotNull Component message, @NotNull ChatPosition position, @Nullable UUID uuid) {
         this.message = message;
         this.position = position;
         this.uuid = Objects.requireNonNullElse(uuid, NULL_UUID);
     }
 
+    public ChatMessagePacket() {
+        this(Component.empty(), ChatPosition.SYSTEM_MESSAGE, NULL_UUID);
+    }
+
     @Override
     public void write(@NotNull BinaryWriter writer) {
         writer.writeComponent(message);