FELIX-639 Logger interface is missing.

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@741709 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/scr/src/main/java/org/apache/felix/scr/impl/Logger.java b/scr/src/main/java/org/apache/felix/scr/impl/Logger.java
new file mode 100644
index 0000000..a5c9143
--- /dev/null
+++ b/scr/src/main/java/org/apache/felix/scr/impl/Logger.java
@@ -0,0 +1,44 @@
+/*
+ * 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 org.apache.felix.scr.impl;
+
+
+/**
+ * The <code>Logger</code> interface defines a simple API to enable some logging
+ * in the XML Parser and ComponentMetadata handling classes and at the same
+ * time not be too intrusive for the unit tests.
+ */
+interface Logger
+{
+
+    /**
+     * Writes a messages for the given <code>ComponentMetadata</code>.
+     * 
+     * @param level The log level of the messages. This corresponds to the log
+     *          levels defined by the OSGi LogService.
+     * @param message The message to print
+     * @param metadata The {@link ComponentMetadata} whose processing caused
+     *          the message. This may be <code>null</code> if the component
+     *          metadata is not known or applicable.
+     * @param ex The <code>Throwable</code> causing the message to be logged.
+     *          This may be <code>null</code>.
+     */
+    void log( int level, String message, ComponentMetadata metadata, Throwable ex );
+
+}