org.apache.flume.interceptor.Interceptor Maven / Gradle / Ivy
/*
* 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.flume.interceptor;
import java.util.List;
import org.apache.flume.Event;
import org.apache.flume.annotations.InterfaceAudience;
import org.apache.flume.annotations.InterfaceStability;
import org.apache.flume.conf.Configurable;
@InterfaceAudience.Public
@InterfaceStability.Stable
public interface Interceptor {
/**
* Any initialization / startup needed by the Interceptor.
*/
public void initialize();
/**
* Interception of a single {@link Event}.
* @param event Event to be intercepted
* @return Original or modified event, or {@code null} if the Event
* is to be dropped (i.e. filtered out).
*/
public Event intercept(Event event);
/**
* Interception of a batch of {@linkplain Event events}.
* @param events Input list of events
* @return Output list of events. The size of output list MUST NOT BE GREATER
* than the size of the input list (i.e. transformation and removal ONLY).
* Also, this method MUST NOT return {@code null}. If all events are dropped,
* then an empty List is returned.
*/
public List intercept(List events);
/**
* Perform any closing / shutdown needed by the Interceptor.
*/
public void close();
/** Builder implementations MUST have a no-arg constructor */
public interface Builder extends Configurable {
public Interceptor build();
}
}