001/* 002 * Copyright 2013 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 */ 016package org.springframework.batch.jsr.item; 017 018import java.io.Serializable; 019 020import javax.batch.api.chunk.ItemReader; 021 022import org.springframework.util.Assert; 023import org.springframework.util.ClassUtils; 024 025/** 026 * Adapter that wraps an {@link ItemReader} for use by Spring Batch. All calls are delegated as appropriate 027 * to the corresponding method on the delegate. 028 * 029 * @author Michael Minella 030 * @since 3.0 031 */ 032public class ItemReaderAdapter<T> extends CheckpointSupport implements org.springframework.batch.item.ItemReader<T> { 033 034 private static final String CHECKPOINT_KEY = "reader.checkpoint"; 035 036 private ItemReader delegate; 037 038 /** 039 * @param reader the {@link ItemReader} implementation to delegate to 040 */ 041 public ItemReaderAdapter(ItemReader reader) { 042 super(CHECKPOINT_KEY); 043 Assert.notNull(reader, "An ItemReader implementation is required"); 044 this.delegate = reader; 045 setExecutionContextName(ClassUtils.getShortName(delegate.getClass())); 046 } 047 048 /* (non-Javadoc) 049 * @see org.springframework.batch.item.ItemReader#read() 050 */ 051 @SuppressWarnings("unchecked") 052 @Override 053 public T read() throws Exception { 054 return (T) delegate.readItem(); 055 } 056 057 /* (non-Javadoc) 058 * @see org.springframework.batch.jsr.item.CheckpointSupport#doClose() 059 */ 060 @Override 061 protected void doClose() throws Exception{ 062 delegate.close(); 063 } 064 065 /* (non-Javadoc) 066 * @see org.springframework.batch.jsr.item.CheckpointSupport#doCheckpoint() 067 */ 068 @Override 069 protected Serializable doCheckpoint() throws Exception { 070 return delegate.checkpointInfo(); 071 } 072 073 /* (non-Javadoc) 074 * @see org.springframework.batch.jsr.item.CheckpointSupport#doOpen(java.io.Serializable) 075 */ 076 @Override 077 protected void doOpen(Serializable checkpoint) throws Exception { 078 delegate.open(checkpoint); 079 } 080}