Only use ColorMapper if jansi is present, ignore it if not

This change allows slf4bukkit to run on Bukkit implementations without jansi by making ColorMapper optional: If it cannot be initialized, colors are not mapped. Instead this may (or may not) be done by the Bukkit implementation, that alos handles the logging system everything the output of slf4bukkit is to.

src/main/java/org/slf4j/impl/BukkitLoggerAdapter.java

@@ -44,17 +44,11 @@
  */
 package org.slf4j.impl;
 
+import com.google.common.collect.ImmutableMap;
+
 import info.ronjenkins.slf4bukkit.ColorMapper;
 import info.ronjenkins.slf4bukkit.ColorMarker;
 
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
 import org.apache.commons.lang.exception.ExceptionUtils;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
@@ -67,7 +61,13 @@ import org.slf4j.helpers.FormattingTuple;
 import org.slf4j.helpers.MessageFormatter;
 import org.yaml.snakeyaml.Yaml;
 
-import com.google.common.collect.ImmutableMap;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 
 /**
  * <p>
@@ -219,11 +219,22 @@ public final class BukkitLoggerAdapter implements Logger {
   private final String                         name;
   // The short name of this simple log instance
   private transient String                     shortLogName                        = null;
+  private final ThreadLocal<ColorMapper>                    mapper;
 
   // NOTE: BukkitPluginLoggerAdapter constructor should have only package access
   // so that only BukkitPluginLoggerFactory be able to create one.
   BukkitLoggerAdapter(final String name) {
     this.name = name;
+    this.mapper = new ThreadLocal<ColorMapper>() {
+      @Override
+      protected ColorMapper initialValue() {
+        try {
+          return ColorMapper.create();
+        } catch (ColorMapper.UnsupportedByBukkitImplementationException ignore) {
+          return null;
+        }
+      }
+    };
   }
 
   /**
@@ -352,7 +363,7 @@ public final class BukkitLoggerAdapter implements Logger {
    *
    * @param property
    *          the config property where the map exists.
-   * @param defaultValue
+   * @param defaultValues
    *          the fallback values returned by this method.
    * @return never null, always contains one mapping for each {@link Level}, and
    *         contains no null keys/values. Equal to {@code defaultValue} if the
@@ -1043,6 +1054,14 @@ public final class BukkitLoggerAdapter implements Logger {
 
     // Log the message.
     logger.log(BukkitLoggerAdapter.slf4jLevelIntToBukkitJULLevel(level),
-               ColorMapper.map(buf.toString()));
+               mapColors(buf.toString()));
+  }
+
+  private String mapColors(String input) {
+    ColorMapper colorMapper = mapper.get();
+    if (colorMapper != null) {
+      return colorMapper.map(input);
+    }
+    return input;
   }
 }