001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018 package org.apache.commons.pipeline; 019 020 021 /** 022 * This interface represents a data channel into which objects can be fed. 023 * Feeders act as intermediaries between stages in a pipeline and the drivers 024 * for subsequent stages. Each {@link StageDriver} implementation will 025 * ordinarily provide a custom Feeder implementation that integrates receiving 026 * objects with its internal stage processing workflow. 027 */ 028 public interface Feeder { 029 /** 030 * This Feeder implementation provides a standard, no-op sink for objects. 031 * It is useful for situations like the terminus of a pipeline, where 032 * there is nothing to be done with a generated object. 033 */ 034 public static final Feeder VOID = new Feeder() { 035 public void feed(Object obj) { } 036 }; 037 038 /** 039 * Feeds the specified object to an underlying receiver. 040 * @param obj The object being fed to the receiver. 041 */ 042 public void feed(Object obj); 043 }