Replace SimpleLogger with FallbackLogger

src/main/java/net/dv8tion/jda/internal/handle/GuildBanHandler.java

@@ -21,7 +21,6 @@
 import net.dv8tion.jda.api.utils.data.DataObject;
 import net.dv8tion.jda.internal.JDAImpl;
 import net.dv8tion.jda.internal.entities.GuildImpl;
-import net.dv8tion.jda.internal.utils.JDALogger;
 
 public class GuildBanHandler extends SocketHandler
 {
@@ -45,7 +44,7 @@ protected Long handleInternally(DataObject content)
         if (guild == null)
         {
             getJDA().getEventCache().cache(EventCache.Type.GUILD, id, responseNumber, allContent, this::handle);
-            EventCache.LOG.debug("Received Guild Member {} event for a Guild not yet cached.", JDALogger.getLazyString(() -> banned ? "Ban" : "Unban"));
+            EventCache.LOG.debug("Received Guild Member {} event for a Guild not yet cached.", banned ? "Ban" : "Unban");
             return null;
         }
 

src/main/java/net/dv8tion/jda/internal/handle/MessageReactionHandler.java

@@ -34,7 +34,6 @@
 import net.dv8tion.jda.internal.entities.MemberImpl;
 import net.dv8tion.jda.internal.entities.channel.concrete.PrivateChannelImpl;
 import net.dv8tion.jda.internal.requests.WebSocketClient;
-import net.dv8tion.jda.internal.utils.JDALogger;
 
 import java.util.List;
 import java.util.Objects;
@@ -73,8 +72,7 @@ protected Long handleInternally(DataObject content)
 
         if (emojiId == null && emojiName == null)
         {
-            WebSocketClient.LOG.debug("Received a reaction {} with no name nor id. json: {}",
-                JDALogger.getLazyString(() -> add ? "add" : "remove"), content);
+            WebSocketClient.LOG.debug("Received a reaction {} with no name nor id. json: {}", add ? "add" : "remove", content);
             return null;
         }
         final long guildId = content.getUnsignedLong("guild_id", 0);

src/main/java/net/dv8tion/jda/internal/utils/FallbackLogger.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2015 Austin Keener, Michael Ritter, Florian Spieß, and the JDA contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dv8tion.jda.internal.utils;
+
+import org.slf4j.Marker;
+import org.slf4j.event.Level;
+import org.slf4j.helpers.FormattingTuple;
+import org.slf4j.helpers.LegacyAbstractLogger;
+import org.slf4j.helpers.MessageFormatter;
+
+import java.time.LocalDateTime;
+
+class FallbackLogger extends LegacyAbstractLogger
+{
+    private final String name;
+
+    public FallbackLogger(String name)
+    {
+        this.name = name;
+    }
+
+    @Override
+    protected String getFullyQualifiedCallerName()
+    {
+        return null;
+    }
+
+    @Override
+    protected void handleNormalizedLoggingCall(Level level, Marker marker, String messagePattern, Object[] arguments, Throwable throwable)
+    {
+        LocalDateTime now = LocalDateTime.now();
+        FormattingTuple result = MessageFormatter.arrayFormat(messagePattern, arguments);
+        System.err.printf("%1$tF %1$tT [%2$s] [%3$s] %4$s%n", now, name, level, result.getMessage());
+        if (throwable != null)
+            throwable.printStackTrace(System.err);
+    }
+
+    @Override
+    public boolean isTraceEnabled()
+    {
+        return false;
+    }
+
+    @Override
+    public boolean isDebugEnabled()
+    {
+        return false;
+    }
+
+    @Override
+    public boolean isInfoEnabled()
+    {
+        return true;
+    }
+
+    @Override
+    public boolean isWarnEnabled()
+    {
+        return true;
+    }
+
+    @Override
+    public boolean isErrorEnabled()
+    {
+        return true;
+    }
+}

src/main/java/net/dv8tion/jda/internal/utils/JDALogger.java

@@ -28,7 +28,7 @@
 /**
  * This class serves as a LoggerFactory for JDA's internals.
  * <br>It will either return a Logger from a SLF4J implementation via {@link org.slf4j.LoggerFactory} if present,
- * or an instance of a custom {@link SimpleLogger} (From slf4j-simple).
+ * or an instance of a custom {@link FallbackLogger}.
  * <p>
  * It also has the utility method {@link #getLazyString(LazyEvaluation)} which is used to lazily construct Strings for Logging.
  */
@@ -83,7 +83,7 @@ private JDALogger() {}
      * Will get the {@link org.slf4j.Logger} with the given log-name
      * or create and cache a fallback logger if there is no SLF4J implementation present.
      * <p>
-     * The fallback logger will be an instance of a slightly modified version of SLF4Js SimpleLogger.
+     * The fallback logger uses a constant logging configuration and prints directly to {@link System#err}.
      *
      * @param  name
      *         The name of the Logger
@@ -96,15 +96,15 @@ public static Logger getLog(String name)
         {
             if (SLF4J_ENABLED)
                 return LoggerFactory.getLogger(name);
-            return LOGS.computeIfAbsent(name, SimpleLogger::new);
+            return LOGS.computeIfAbsent(name, FallbackLogger::new);
         }
     }
 
     /**
      * Will get the {@link org.slf4j.Logger} for the given Class
      * or create and cache a fallback logger if there is no SLF4J implementation present.
      * <p>
-     * The fallback logger will be an instance of a slightly modified version of SLF4Js SimpleLogger.
+     * The fallback logger uses a constant logging configuration and prints directly to {@link System#err}.
      *
      * @param  clazz
      *         The class used for the Logger name
@@ -117,7 +117,7 @@ public static Logger getLog(Class<?> clazz)
         {
             if (SLF4J_ENABLED)
                 return LoggerFactory.getLogger(clazz);
-            return LOGS.computeIfAbsent(clazz.getName(), (n) -> new SimpleLogger(clazz.getSimpleName()));
+            return LOGS.computeIfAbsent(clazz.getName(), (n) -> new FallbackLogger(clazz.getSimpleName()));
         }
     }
 
@@ -144,7 +144,7 @@ public String toString()
                 {
                     StringWriter sw = new StringWriter();
                     ex.printStackTrace(new PrintWriter(sw));
-                    return "Error while evaluating lazy String... " + sw.toString();
+                    return "Error while evaluating lazy String... " + sw;
                 }
             }
         };