new file mode 100644
--- /dev/null
+++ b/library/log4php/pattern/LoggerPatternConverterMDC.php
@@ -0,0 +1,55 @@
+<?php
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 log4php
+ */
+
+/**
+ * Returns the Mapped Diagnostic Context value corresponding to the given key.
+ *
+ * Options:
+ *  [0] the MDC key
+ *
+ * @package log4php
+ * @subpackage pattern
+ * @version $Revision: 1326626 $
+ * @since 2.3
+ */
+class LoggerPatternConverterMDC extends LoggerPatternConverter {
+
+    private $key;
+
+    public function activateOptions() {
+        if (isset($this->option) && $this->option !== '') {
+            $this->key = $this->option;
+        }
+    }
+
+    public function convert(LoggerLoggingEvent $event) {
+        if (isset($this->key)) {
+            return $event->getMDC($this->key);
+        } else {
+            $buff = array();
+            $map = $event->getMDCMap();
+            foreach ($map as $key => $value) {
+                $buff [] = "$key=$value";
+            }
+            return implode(', ', $buff);
+        }
+    }
+}
+ 
\ No newline at end of file