001/* 002 * Copyright 2006-2007 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.batch.integration.chunk; 018 019 020/** 021 * Interface for a remote worker in the Remote Chunking pattern. A request comes from a master process containing some 022 * items to be processed. Once the items are done with a response needs to be generated containing a summary of the 023 * result. 024 * 025 * @author Dave Syer 026 * 027 * @param <T> the type of the items to be processed (it is recommended to use a Memento like a primary key) 028 */ 029public interface ChunkHandler<T> { 030 031 /** 032 * Handle the chunk, processing all the items and returning a response summarising the result. If the result is a 033 * failure then the response should say so. The handler only throws an exception if it needs to roll back a 034 * transaction and knows that the request will be re-delivered (if not to the same handler then to one processing 035 * the same Step). 036 * 037 * @param chunk a request containing the chunk to process 038 * @return a response summarising the result 039 * 040 * @throws Exception if the handler needs to roll back a transaction and have the chunk re-delivered 041 */ 042 ChunkResponse handleChunk(ChunkRequest<T> chunk) throws Exception; 043 044}