+package org.apache.log4j.rewrite;
+
+import org.apache.log4j.spi.LoggingEvent;
+
+/*
+* 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.
+*/
+
+/**
+ * This interface is implemented to provide a rewrite
+ * strategy for RewriteAppender. RewriteAppender will
+ * call the rewrite method with a source logging event.
+ * The strategy may return that event, create a new event
+ * or return null to suppress the logging request.
+ */
+public interface RewritePolicy {
+ /**
+ * Rewrite a logging event.
+ * @param source a logging event that may be returned or
+ * used to create a new logging event.
+ * @return a logging event or null to suppress processing.
+ */
+ LoggingEvent rewrite(final LoggingEvent source);
+}