我有一个巨大的XML(~2GB),我需要添加新元素并修改旧元素.例如,我有：
<books>
<book>....</book>
...
<book>....</book>
</books>
并希望得到：
<books>
<book>
<index></index>
....
</book>
...
<book>
<index></index>
....
</book>
</books>
我使用了以下代码：
XMLInputFactory inFactory = XMLInputFactory.newInstance();
XMLEventReader eventReader = inFactory.createXMLEventReader(new FileInputStream(file));
XMLOutputFactory factory = XMLOutputFactory.newInstance();
XMLStreamWriter writer = factory.createXMLStreamWriter(new FileWriter(file,true));
while (eventReader.hasNext()) {
XMLEvent event = eventReader.nextEvent();
if (event.getEventType() == XMLEvent.START_ELEMENT) {
if (event.asStartElement().getName().toString().equalsIgnoreCase("book")) {
writer.writeStartElement("index");
writer.writeEndElement();
}
}
}
writer.close();
但结果如下：
<books> <book>....</book> .... <book>....</book> </books><index></index>
有任何想法吗？
尝试这个
XMLInputFactory inFactory = XMLInputFactory.newInstance();
XMLEventReader eventReader = inFactory.createXMLEventReader(new FileInputStream("1.xml"));
XMLOutputFactory factory = XMLOutputFactory.newInstance();
XMLEventWriter writer = factory.createXMLEventWriter(new FileWriter(file));
XMLEventFactory eventFactory = XMLEventFactory.newInstance();
while (eventReader.hasNext()) {
XMLEvent event = eventReader.nextEvent();
writer.add(event);
if (event.getEventType() == XMLEvent.START_ELEMENT) {
if (event.asStartElement().getName().toString().equalsIgnoreCase("book")) {
writer.add(eventFactory.createStartElement("",null,"index"));
writer.add(eventFactory.createEndElement("","index"));
}
}
}
writer.close();
笔记
新的FileWriter(file,true)附加到文件的末尾,你几乎不需要它
equalsIgnoreCase(“book”)是个坏主意,因为XML区分大小写
