/*
* Copyright 2002-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.util.xml;
import java.util.NoSuchElementException;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.Characters;
import javax.xml.stream.events.XMLEvent;
import org.springframework.util.ClassUtils;
/**
* Abstract base class for {@code XMLEventReader}s.
*
* @author Arjen Poutsma
* @since 5.0
*/
abstract class AbstractXMLEventReader implements XMLEventReader {
private boolean closed;
@Override
public Object next() {
try {
return nextEvent();
}
catch (XMLStreamException ex) {
throw new NoSuchElementException();
}
}
@Override
public void remove() {
throw new UnsupportedOperationException(
"remove not supported on " + ClassUtils.getShortName(getClass()));
}
@Override
public String getElementText() throws XMLStreamException {
checkIfClosed();
if (!peek().isStartElement()) {
throw new XMLStreamException("Not at START_ELEMENT");
}
StringBuilder builder = new StringBuilder();
while (true) {
XMLEvent event = nextEvent();
if (event.isEndElement()) {
break;
}
else if (!event.isCharacters()) {
throw new XMLStreamException(
"Unexpected event [" + event + "] in getElementText()");
}
Characters characters = event.asCharacters();
if (!characters.isIgnorableWhiteSpace()) {
builder.append(event.asCharacters().getData());
}
}
return builder.toString();
}
@Override
public XMLEvent nextTag() throws XMLStreamException {
checkIfClosed();
while (true) {
XMLEvent event = nextEvent();
switch (event.getEventType()) {
case XMLStreamConstants.START_ELEMENT:
case XMLStreamConstants.END_ELEMENT:
return event;
case XMLStreamConstants.END_DOCUMENT:
return null;
case XMLStreamConstants.SPACE:
case XMLStreamConstants.COMMENT:
case XMLStreamConstants.PROCESSING_INSTRUCTION:
continue;
case XMLStreamConstants.CDATA:
case XMLStreamConstants.CHARACTERS:
if (!event.asCharacters().isWhiteSpace()) {
throw new XMLStreamException(
"Non-ignorable whitespace CDATA or CHARACTERS event in nextTag()");
}
break;
default:
throw new XMLStreamException("Received event [" + event +
"], instead of START_ELEMENT or END_ELEMENT.");
}
}
}
/**
* Throws an {@code IllegalArgumentException} when called.
* @throws IllegalArgumentException when called.
*/
@Override
public Object getProperty(String name) throws IllegalArgumentException {
throw new IllegalArgumentException("Property not supported: [" + name + "]");
}
@Override
public void close() {
this.closed = true;
}
/**
* Returns {@code true} if closed; {@code false} otherwise.
* @see #close()
*/
protected boolean isClosed() {
return this.closed;
}
/**
* Checks if the reader is closed, and throws a {@code XMLStreamException} if so.
* @throws XMLStreamException if the reader is closed
* @see #close()
* @see #isClosed()
*/
protected void checkIfClosed() throws XMLStreamException {
if (isClosed()) {
throw new XMLStreamException("XMLEventReader has been closed");
}
}
}