From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Noah van der Aa <ndvdaa@gmail.com>
Date: Sat, 22 Oct 2022 14:47:45 +0200
Subject: [PATCH] Detect headless JREs

Crashes caused by the missing AWT dependency come up in the support channels fairly often.
This patch detects the missing dependency and stops the server with a clear error message,
containing a link to instructions on how to install a non-headless JRE.

diff --git a/src/main/java/io/papermc/paper/util/ServerEnvironment.java b/src/main/java/io/papermc/paper/util/ServerEnvironment.java
index 6bd0afddbcc461149dfe9a5c7a86fff6ea13a5f1..148d233f4f5278ff39eacdaa0f4f0e7d73be936a 100644
--- a/src/main/java/io/papermc/paper/util/ServerEnvironment.java
+++ b/src/main/java/io/papermc/paper/util/ServerEnvironment.java
@@ -37,4 +37,14 @@ public class ServerEnvironment {
     public static boolean userIsRootOrAdmin() {
         return RUNNING_AS_ROOT_OR_ADMIN;
     }
+
+    public static String awtDependencyCheck() {
+        try {
+            new java.awt.Color(0);
+        } catch (UnsatisfiedLinkError e) {
+            return e.getClass().getName() + ": " + e.getMessage();
+        }
+
+        return null;
+    }
 }
diff --git a/src/main/java/net/minecraft/server/Main.java b/src/main/java/net/minecraft/server/Main.java
index 1147044f2c4c2e9510cb6e5c38b6abe85ec994e1..a3c400bb4ee5d8f2985f4bc7e3e35be548177cc6 100644
--- a/src/main/java/net/minecraft/server/Main.java
+++ b/src/main/java/net/minecraft/server/Main.java
@@ -170,6 +170,18 @@ public class Main {
                 return;
             }
 
+            // Paper start - Warn on headless
+            String awtException = io.papermc.paper.util.ServerEnvironment.awtDependencyCheck();
+            if (awtException != null) {
+                Main.LOGGER.error("You are using a headless JRE distribution.");
+                Main.LOGGER.error("This distribution is missing certain graphic libraries that the Minecraft server needs to function.");
+                Main.LOGGER.error("For instructions on how to install the non-headless JRE, see https://docs.papermc.io/misc/java-install");
+                Main.LOGGER.error("");
+                Main.LOGGER.error(awtException);
+                return;
+            }
+            // Paper end
+
             org.spigotmc.SpigotConfig.disabledAdvancements = spigotConfiguration.getStringList("advancements.disabled"); // Paper - fix SPIGOT-5885, must be set early in init
             // Paper start - fix SPIGOT-5824
             File file;