001/* 002 * Copyright 2006-2013 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.core.listener; 017 018import java.util.Iterator; 019import java.util.List; 020 021import org.springframework.batch.core.ItemReadListener; 022import org.springframework.core.Ordered; 023 024/** 025 * @author Lucas Ward 026 * @author Dave Syer 027 * 028 */ 029public class CompositeItemReadListener<T> implements ItemReadListener<T> { 030 031 private OrderedComposite<ItemReadListener<? super T>> listeners = new OrderedComposite<ItemReadListener<? super T>>(); 032 033 /** 034 * Public setter for the listeners. 035 * 036 * @param itemReadListeners list of {@link ItemReadListener}s to be called when read events occur. 037 */ 038 public void setListeners(List<? extends ItemReadListener<? super T>> itemReadListeners) { 039 this.listeners.setItems(itemReadListeners); 040 } 041 042 /** 043 * Register additional listener. 044 * 045 * @param itemReaderListener instance of {@link ItemReadListener} to be registered. 046 */ 047 public void register(ItemReadListener<? super T> itemReaderListener) { 048 listeners.add(itemReaderListener); 049 } 050 051 /** 052 * Call the registered listeners in reverse order, respecting and 053 * prioritising those that implement {@link Ordered}. 054 * @see org.springframework.batch.core.ItemReadListener#afterRead(java.lang.Object) 055 */ 056 @Override 057 public void afterRead(T item) { 058 for (Iterator<ItemReadListener<? super T>> iterator = listeners.reverse(); iterator.hasNext();) { 059 ItemReadListener<? super T> listener = iterator.next(); 060 listener.afterRead(item); 061 } 062 } 063 064 /** 065 * Call the registered listeners in order, respecting and prioritising those 066 * that implement {@link Ordered}. 067 * @see org.springframework.batch.core.ItemReadListener#beforeRead() 068 */ 069 @Override 070 public void beforeRead() { 071 for (Iterator<ItemReadListener<? super T>> iterator = listeners.iterator(); iterator.hasNext();) { 072 ItemReadListener<? super T> listener = iterator.next(); 073 listener.beforeRead(); 074 } 075 } 076 077 /** 078 * Call the registered listeners in reverse order, respecting and 079 * prioritising those that implement {@link Ordered}. 080 * @see org.springframework.batch.core.ItemReadListener#onReadError(java.lang.Exception) 081 */ 082 @Override 083 public void onReadError(Exception ex) { 084 for (Iterator<ItemReadListener<? super T>> iterator = listeners.reverse(); iterator.hasNext();) { 085 ItemReadListener<? super T> listener = iterator.next(); 086 listener.onReadError(ex); 087 } 088 } 089}