Jaxb org.xml.sax.saxparseexception : premature end of file

如果在使用JAXB把xml文件unmarshal成vo(XSD自动生成的vo)时碰到如下错误：
org.xml.sax.saxparseexception : premature end of file
很有可能时你直接读取文件为inputstream，然后将inputstream作为构建unmarshal需要的source参数。InputSource inputSource = new InputSource(inputStream)。即你是按如下方式调用下面提供的方法的

InputStream msgInputStream = new ClassPathResource("data/MessageSample.xml").getInputStream();
Wrapper messageWrapper = parseMessage(msgInputStream, Wrapper.class);

解决方案是，首先将文件内容读成字符串content，让后用字符串构建ByteArrayInputStream bis,由bis来构建source就不会报错了。InputSource inputSource = new InputSource(bis),即如下使用上面的parseMessage方法

parseMessage(new ByteArrayInputStream(content.getBytes()), targetType)

文中用到的parseMessage方法

private <E> E parseMessage(InputStream inputStream, Class<E> targetType) throws JAXBException, SAXException, ParserConfigurationException {
	InputSource inputSource = new InputSource(inputStream);
	JAXBContext jc = JAXBContext.newInstance("generated.vo");
	Unmarshaller unmarshaller = jc.createUnmarshaller();
	final SAXParserFactory sax = SAXParserFactory.newInstance();
	sax.setNamespaceAware(true);
	final XMLReader reader = sax.newSAXParser().getXMLReader();
	final Source source = new SAXSource(reader, inputSource);
	JAXBElement<E> el = unmarshaller.unmarshal(source, targetType);
	E vo = el.getValue();
	return vo;
}