小编mar*_*sen的帖子

让我们创建一个包含两个属性值的XML文件,其中包含一个扩展的unicode char

XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();

try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(ERROR_XML), "UTF-8"))) {
XMLStreamWriter xmlStreamWriter = outputFactory.createXMLStreamWriter(writer);

xmlStreamWriter.writeStartDocument();
xmlStreamWriter.writeCharacters("\n");
xmlStreamWriter.writeStartElement("start");
xmlStreamWriter.writeAttribute("test1", "11");
xmlStreamWriter.writeAttribute("test2", "22");
xmlStreamWriter.writeEndElement();
xmlStreamWriter.writeEndDocument();
}

生成的文件如下所示:

<?xml version="1.0" ?>
<start test1="11" test2="22"></start>

如果再次读入并检查属性值

XMLInputFactory inputFactory = XMLInputFactory.newInstance();
try (BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(ERROR_XML), "UTF-8"))) {
XMLStreamReader xmlStreamReader = inputFactory.createXMLStreamReader(reader);

xmlStreamReader.nextTag();
if (XMLStreamReader.START_ELEMENT == xmlStreamReader.getEventType() &&
    "start".equals(xmlStreamReader.getLocalName())) 
{
    System.out.println(xmlStreamReader.getAttributeValue(0));
    System.out.println(xmlStreamReader.getAttributeValue(1));
}}

这将打印

11
22

令人惊讶的是,第二个属性值包含2次扩展的unicode char!

以下任何使用扩展char作为属性值都会增加此计数.在一个案例中,我收到了12000个相同字符的属性值,而不是一个.这里发生了什么？