missed from r1197969 - DIGESTER-156 :(

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/digester/trunk@1197971 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/commons/digester3/binder/AddAliasBuilder.java b/src/main/java/org/apache/commons/digester3/binder/AddAliasBuilder.java
new file mode 100644
index 0000000..7f5afa2
--- /dev/null
+++ b/src/main/java/org/apache/commons/digester3/binder/AddAliasBuilder.java
@@ -0,0 +1,59 @@
+package org.apache.commons.digester3.binder;
+
+/*
+ * 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.
+ */
+
+import java.util.Map;
+
+/**
+ * @since 3.2
+ * @param <B> the parent builder type.
+ */
+public final class AddAliasBuilder<B>
+{
+
+    private final B parentBuilder;
+
+    private final Map<String, String> aliases;
+
+    private final String alias;
+
+    AddAliasBuilder( B parentBuilder, Map<String, String> aliases, String alias )
+    {
+        this.parentBuilder = parentBuilder;
+        this.aliases = aliases;
+        this.alias = alias;
+    }
+
+    /**
+     * Allows expressing the input property name alias.
+     *
+     * @param propertyName The java bean property to be assigned the value
+     * @return the parent builder to chain.
+     */
+    public B forProperty( /*@Nullable*/ String propertyName )
+    {
+        if ( alias != null )
+        {
+            aliases.put( alias, propertyName );
+        }
+        return parentBuilder;
+    }
+
+}