Add System.out.println catcher

patches/server/0731-Add-System.out.println-catcher.patch

@@ -0,0 +1,106 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: underscore11code <minecrafter11mrt@gmail.com>
+Date: Fri, 23 Jul 2021 23:01:42 -0700
+Subject: [PATCH] Add System.out.println catcher
+
+
+diff --git a/src/main/java/io/papermc/paper/logging/SysoutCatcher.java b/src/main/java/io/papermc/paper/logging/SysoutCatcher.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..b55228f1e5f3fed43f19e83dbdf77e93258c4cd8
+--- /dev/null
++++ b/src/main/java/io/papermc/paper/logging/SysoutCatcher.java
+@@ -0,0 +1,74 @@
++package io.papermc.paper.logging;
++
++import com.google.common.collect.ImmutableSet;
++import org.apache.commons.lang.StringUtils;
++import org.bukkit.Bukkit;
++import org.bukkit.plugin.Plugin;
++import org.bukkit.plugin.java.JavaPlugin;
++
++import java.io.PrintStream;
++import java.util.Set;
++
++public final class SysoutCatcher {
++    private static final String OUT_PREFIX = "[STDOUT] ";
++    private static final String ERR_PREFIX = "[STDERR] ";
++    private final StackWalker stackWalker = StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE);
++    private final Set<String> blacklistedPlugins;
++
++    public SysoutCatcher() {
++        final String rawBlacklist = System.getProperty("io.papermc.paper.suppress.sout.nags");
++        if (StringUtils.isNotBlank(rawBlacklist)) {
++            blacklistedPlugins = ImmutableSet.<String>builder().add(rawBlacklist.split(",")).build();
++        } else blacklistedPlugins = ImmutableSet.of();
++
++        // Listen to System.out.println
++        PrintStream wrappedOut = new PrintStream(System.out) {
++            @Override
++            public void println(String line) {
++                Class<?> clazz = stackWalker.getCallerClass();
++                try {
++                    JavaPlugin plugin = JavaPlugin.getProvidingPlugin(clazz);
++
++                    // Instead of just printing the message, send it to the plugin's logger
++                    plugin.getLogger().info(OUT_PREFIX + line);
++                    nag(plugin);
++                } catch (IllegalArgumentException e) {
++                    // If anything happens, the calling class doesn't exist, there is no JavaPlugin that "owns" the calling class, etc
++                    // Just print out normally, with some added information
++                    Bukkit.getLogger().info(String.format("[%s] %s %s", OUT_PREFIX, clazz.getName(), line));
++                }
++            }
++        };
++
++        // Listen to System.err.println
++        PrintStream wrappedErr = new PrintStream(System.err) {
++            @Override
++            public void println(String line) {
++                Class<?> clazz = stackWalker.getCallerClass();
++                try {
++                    JavaPlugin plugin = JavaPlugin.getProvidingPlugin(clazz);
++
++                    // Instead of just printing the message, send it to the plugin's logger
++                    plugin.getLogger().severe(ERR_PREFIX + line);
++                    nag(plugin);
++                } catch (IllegalArgumentException e) {
++                    // If anything happens, the calling class doesn't exist, there is no JavaPlugin that "owns" the calling class, etc
++                    // Just print out normally, with some added information
++                    Bukkit.getLogger().info(String.format("[%s] %s %s", ERR_PREFIX, clazz.getName(), line));
++                }
++            }
++        };
++
++        // Set the two PrintStreams so they're used
++        System.setOut(wrappedOut);
++        System.setErr(wrappedErr);
++    }
++
++    private void nag(Plugin plugin) {
++        if (this.blacklistedPlugins.contains(plugin.getName())) return;
++        Bukkit.getLogger().warning(String.format("Nag author(s): '%s' of '%s' about their usage of System.out/err.print. " +
++                "Please use your plugin's logger instead (JavaPlugin#getLogger).",
++            plugin.getDescription().getAuthors(),
++            plugin.getName()));
++    }
++}
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+index 9954e45c32a4b6d80fe912ed9d55cd4fc8c4e98b..6d7f16fede01c19f638e1dcdae8b07b79cd86dc0 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+@@ -18,6 +18,7 @@ import com.mojang.serialization.Lifecycle;
+ import io.netty.buffer.ByteBuf;
+ import io.netty.buffer.ByteBufOutputStream;
+ import io.netty.buffer.Unpooled;
++import io.papermc.paper.logging.SysoutCatcher;
+ import it.unimi.dsi.fastutil.objects.Object2ObjectLinkedOpenHashMap;
+ import java.awt.image.BufferedImage;
+ import java.io.File;
+@@ -277,6 +278,7 @@ public final class CraftServer implements Server {
+     public int reloadCount;
+     private final io.papermc.paper.datapack.PaperDatapackManager datapackManager; // Paper
+     public static Exception excessiveVelEx; // Paper - Velocity warnings
++    private final SysoutCatcher sysoutCatcher = new SysoutCatcher(); // Paper
+
+     static {
+         ConfigurationSerialization.registerClass(CraftOfflinePlayer.class);