forgot to add file need to close PR 48829.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@1040171 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/compilers/CompilerAdapterExtension.java

@@ -0,0 +1,40 @@
+/*
+ *  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.tools.ant.taskdefs.compilers;
+
+/**
+ * Extension interface for compilers that support source extensions
+ * other than .java.
+ * 
+ * @since Ant 1.8.2
+ */
+public interface CompilerAdapterExtension {
+
+    /**
+     * Returns a list of source file extensions that are recognized by
+     * this compiler adapter.
+     *
+     * <p>For example, most compiler adapters will return [ "java" ],
+     * but a compiler adapter that can compile both Java and Groovy
+     * source code would return [ "java", "groovy" ].</p>
+     * 
+     * @return list of source file extensions recognized by this
+     * compiler adapter.
+     */
+    String[] getSupportedFileExtensions();
+}