Adapt System.(out|err) to log4j.

proxy/build.gradle

@@ -38,6 +38,7 @@ dependencies {
     compile "org.apache.logging.log4j:log4j-api:${log4jVersion}"
     compile "org.apache.logging.log4j:log4j-core:${log4jVersion}"
     compile "org.apache.logging.log4j:log4j-slf4j-impl:${log4jVersion}"
+    compile "org.apache.logging.log4j:log4j-iostreams:${log4jVersion}"
 
     compile 'net.sf.jopt-simple:jopt-simple:5.0.4' // command-line options
     compile 'net.minecrell:terminalconsoleappender:1.1.1'
@@ -63,11 +64,14 @@ shadowJar {
     exclude 'it/unimi/dsi/fastutil/ints/IntAVL*'
     exclude 'it/unimi/dsi/fastutil/ints/IntArray*'
     exclude 'it/unimi/dsi/fastutil/ints/IntBi*'
+    exclude 'it/unimi/dsi/fastutil/ints/IntLinked*'
     exclude 'it/unimi/dsi/fastutil/ints/IntList*'
     exclude 'it/unimi/dsi/fastutil/ints/IntOpen*'
     exclude 'it/unimi/dsi/fastutil/ints/IntRB*'
     exclude 'it/unimi/dsi/fastutil/ints/IntSet*'
     exclude 'it/unimi/dsi/fastutil/ints/IntSorted*'
+    exclude 'it/unimi/dsi/fastutil/ints/*Priority*'
+    exclude 'it/unimi/dsi/fastutil/ints/*BigList*'
     exclude 'it/unimi/dsi/fastutil/io/**'
     exclude 'it/unimi/dsi/fastutil/longs/**'
     exclude 'it/unimi/dsi/fastutil/objects/*ObjectArray*'

proxy/src/main/java/com/velocitypowered/proxy/VelocityServer.java

@@ -146,6 +146,7 @@ public class VelocityServer implements ProxyServer {
       "console", "cm", "configuration"})
   void start() {
     logger.info("Booting up {} {}...", getVersion().getName(), getVersion().getVersion());
+    console.setupStreams();
 
     serverKeyPair = EncryptionUtils.createRsaKeyPair(1024);
 

proxy/src/main/java/com/velocitypowered/proxy/console/VelocityConsole.java

@@ -5,14 +5,17 @@ import com.velocitypowered.api.permission.PermissionFunction;
 import com.velocitypowered.api.permission.Tristate;
 import com.velocitypowered.api.proxy.ConsoleCommandSource;
 import com.velocitypowered.proxy.VelocityServer;
+import java.io.PrintWriter;
 import java.util.List;
 import net.kyori.text.Component;
 import net.kyori.text.TextComponent;
 import net.kyori.text.format.TextColor;
 import net.kyori.text.serializer.ComponentSerializers;
 import net.minecrell.terminalconsole.SimpleTerminalConsole;
+import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.io.IoBuilder;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.jline.reader.Candidate;
 import org.jline.reader.LineReader;
@@ -39,6 +42,15 @@ public final class VelocityConsole extends SimpleTerminalConsole implements Cons
     return this.permissionFunction.getPermissionValue(permission);
   }
 
+  public void setupStreams() {
+    System.setOut(IoBuilder.forLogger(logger)
+        .setLevel(Level.INFO)
+        .buildPrintStream());
+    System.setErr(IoBuilder.forLogger(logger)
+        .setLevel(Level.ERROR)
+        .buildPrintStream());
+  }
+
   public void setupPermissions() {
     PermissionsSetupEvent event = new PermissionsSetupEvent(this,
         s -> PermissionFunction.ALWAYS_TRUE);