Use an actual logger

PhyConDebugLogging.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration>
+    <Loggers>
+        <Logger name="PhyNet">
+            <AppenderRef ref="SysOut" level="debug"/>
+        </Logger>
+    </Loggers>
+</Configuration>

build.gradle

@@ -1,5 +1,5 @@
 plugins {
-	id "fabric-loom" version "0.5-SNAPSHOT"
+	id "fabric-loom" version "0.6.49"
 	id "maven-publish"
     id "org.jetbrains.kotlin.jvm" version "1.4.30"
 }
@@ -12,6 +12,7 @@ version = project.mod_version
 group = project.maven_group
 
 minecraft {
+	log4jConfigs.from "PhyConDebugLogging.xml"
 }
 
 repositories {

src/main/kotlin/net/shadowfacts/phycon/PhysicalConnectivity.kt

@@ -7,6 +7,7 @@ import net.shadowfacts.phycon.init.PhyBlocks
 import net.shadowfacts.phycon.init.PhyItems
 import net.shadowfacts.phycon.init.PhyScreens
 import net.shadowfacts.phycon.networking.*
+import org.apache.logging.log4j.LogManager
 
 /**
  * @author shadowfacts
@@ -15,6 +16,8 @@ object PhysicalConnectivity: ModInitializer {
 
 	val MODID = "phycon"
 
+	val NETWORK_LOGGER = LogManager.getLogger("PhyNet")
+
 	override fun onInitialize() {
 		PhyBlocks.init()
 		PhyBlockEntities.init()

src/main/kotlin/net/shadowfacts/phycon/network/DeviceBlockEntity.kt

@@ -6,6 +6,7 @@ import net.minecraft.block.entity.BlockEntity
 import net.minecraft.block.entity.BlockEntityType
 import net.minecraft.nbt.CompoundTag
 import net.minecraft.util.Tickable
+import net.shadowfacts.phycon.PhysicalConnectivity
 import net.shadowfacts.phycon.api.PacketSink
 import net.shadowfacts.phycon.api.PacketSource
 import net.shadowfacts.phycon.api.Interface
@@ -52,6 +53,7 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type),
 	abstract override fun handle(packet: Packet)
 
 	private fun doHandlePacket(packet: Packet) {
+		PhysicalConnectivity.NETWORK_LOGGER.debug("{} ({}) received packet: {}", this, ipAddress, packet)
 		when (packet) {
 			is DeviceRemovedPacket -> {
 				arpTable.remove(packet.source)
@@ -65,13 +67,12 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type),
 	}
 
 	override fun receive(frame: EthernetFrame) {
-		println("$this ($ipAddress, ${macAddress}) received frame from ${frame.source}: $frame")
+		PhysicalConnectivity.NETWORK_LOGGER.debug("{} ({}, {}) received frame from {}: {}", this, ipAddress, macAddress, frame.source, frame)
 		when (frame) {
 			is ARPQueryFrame -> handleARPQuery(frame)
 			is ARPResponseFrame -> handleARPResponse(frame)
 			is PacketFrame -> {
 				if (frame.packet.destination.isBroadcast || frame.packet.destination == ipAddress) {
-					println("$this ($ipAddress) received packet: ${frame.packet}")
 					doHandlePacket(frame.packet)
 				}
 			}
@@ -79,17 +80,17 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type),
 	}
 
 	private fun handleARPQuery(frame: ARPQueryFrame) {
-		println("$this ($ipAddress) received ARP query for ${frame.queryIP}")
+		PhysicalConnectivity.NETWORK_LOGGER.debug("{}, ({}), received ARP query for {}", this, ipAddress, frame.queryIP)
 		arpTable[frame.sourceIP] = frame.source
 		if (frame.queryIP == ipAddress) {
-			println("$this ($ipAddress) sending ARP response to ${frame.source} with $macAddress")
+			PhysicalConnectivity.NETWORK_LOGGER.debug("{} ({}) sending ARP response to {} with {}", this, ipAddress, frame.sourceIP, macAddress)
 			send(ARPResponseFrame(ipAddress, macAddress, frame.source))
 		}
 	}
 
 	private fun handleARPResponse(frame: ARPResponseFrame) {
 		arpTable[frame.query] = frame.source
-		println("$this ($ipAddress) received ARP response for ${frame.query} with ${frame.source}")
+		PhysicalConnectivity.NETWORK_LOGGER.debug("{}, ({}) received ARP response for {} with {}", this, ipAddress, frame.query, frame.source)
 
 		val toRemove = packetQueue.filter { (packet, _) ->
 			if (packet.destination == frame.query) {
@@ -110,7 +111,7 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type),
 		} else {
 			packetQueue.add(PendingPacket(packet, counter))
 
-			println("$this ($ipAddress) sending ARP query for ${packet.destination}")
+			PhysicalConnectivity.NETWORK_LOGGER.debug("{} ({}) sending ARP query for {}", this, ipAddress, packet.destination)
 			send(ARPQueryFrame(packet.destination, ipAddress, macAddress))
 		}
 	}

src/main/kotlin/net/shadowfacts/phycon/network/block/netswitch/SwitchBlockEntity.kt

@@ -7,6 +7,7 @@ import net.minecraft.entity.ItemEntity
 import net.minecraft.nbt.CompoundTag
 import net.minecraft.util.Tickable
 import net.minecraft.util.math.Direction
+import net.shadowfacts.phycon.PhysicalConnectivity
 import net.shadowfacts.phycon.api.Interface
 import net.shadowfacts.phycon.api.frame.EthernetFrame
 import net.shadowfacts.phycon.api.frame.PacketFrame
@@ -53,10 +54,10 @@ class SwitchBlockEntity: BlockEntity(PhyBlockEntities.SWITCH),
 
 		if (frame.destination.type != MACAddress.Type.BROADCAST && macTable.containsKey(frame.destination)) {
 			val dir = macTable[frame.destination]!!
-			println("$this (${fromItf.side}, ${fromItf.macAddress}) forwarding $frame to side $dir")
+			PhysicalConnectivity.NETWORK_LOGGER.debug("{} ({}, {}) forwarding {} to side {}", this, fromItf.side, fromItf.macAddress, frame, dir)
 			interfaceForSide(dir).send(frame)
 		} else {
-			println("$this (${fromItf.side}, ${fromItf.macAddress}) flooding $frame")
+			PhysicalConnectivity.NETWORK_LOGGER.debug("{} ({}, {}) flooding {}", this, fromItf.side, fromItf.macAddress, frame)
 			flood(frame, fromItf)
 		}
 	}