001/* 002 * Copyright 2014 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.item.xml.stax; 018 019import java.io.IOException; 020import java.io.Writer; 021import java.util.LinkedList; 022import java.util.List; 023 024import javax.xml.namespace.QName; 025import javax.xml.stream.XMLEventWriter; 026import javax.xml.stream.XMLStreamException; 027import javax.xml.stream.events.XMLEvent; 028 029import org.springframework.dao.DataAccessResourceFailureException; 030import org.springframework.util.StringUtils; 031 032/** 033 * Delegating XMLEventWriter, which writes EndElement events that match a given collection of QNames directly 034 * to the underlying java.io.Writer instead of to the delegate XMLEventWriter. 035 * 036 * @author Jimmy Praet 037 * @since 3.0 038 */ 039public class UnopenedElementClosingEventWriter extends AbstractEventWriterWrapper { 040 041 private LinkedList<QName> unopenedElements; 042 043 private Writer ioWriter; 044 045 public UnopenedElementClosingEventWriter(XMLEventWriter wrappedEventWriter, Writer ioWriter, List<QName> unopenedElements) { 046 super(wrappedEventWriter); 047 this.unopenedElements = new LinkedList<QName>(unopenedElements); 048 this.ioWriter = ioWriter; 049 } 050 051 /* (non-Javadoc) 052 * @see org.springframework.batch.item.xml.stax.AbstractEventWriterWrapper#add(javax.xml.stream.events.XMLEvent) 053 */ 054 @Override 055 public void add(XMLEvent event) throws XMLStreamException { 056 if (isUnopenedElementCloseEvent(event)) { 057 QName element = unopenedElements.removeLast(); 058 String nsPrefix = !StringUtils.hasText(element.getPrefix()) ? "" : element.getPrefix() + ":"; 059 try { 060 super.flush(); 061 ioWriter.write("</" + nsPrefix + element.getLocalPart() + ">"); 062 ioWriter.flush(); 063 } 064 catch (IOException ioe) { 065 throw new DataAccessResourceFailureException("Unable to close tag: " + element, ioe); 066 } 067 } else { 068 super.add(event); 069 } 070 } 071 072 private boolean isUnopenedElementCloseEvent(XMLEvent event) { 073 if (unopenedElements.isEmpty()) { 074 return false; 075 } else if (!event.isEndElement()) { 076 return false; 077 } else { 078 return unopenedElements.getLast().equals(event.asEndElement().getName()); 079 } 080 } 081 082}