w3c.dom写xml文件时候 如果对Element元素进行操作，而将该Element赋给另一个document元素时候，会报错：
org.w3c.dom.DOMException: WRONG_DOCUMENT_ERR: A node is used in a different document than the one that created it.
由于Element元素不是同一个document元素生成的，所以会报错，此时 要把该Element赋给另一个xml文件时候，需要通过：
public static void sendAlarm(List<Element> elements) {
if(elements != null && !elements.isEmpty()){
ObjectOutputStream oos = null;
try {
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = dbf.newDocumentBuilder();
Transformer transformer = TransformerFactory.newInstance().newTransformer();
oos = new ObjectOutputStream(new Socket(host, port).getOutputStream());
transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
for (Element element : elements){
Document doc = builder.newDocument();
<strong><span style="font-size:18px;color:#339999;">doc.appendChild(doc.importNode(element, true));</span></strong>
//document 转 string
ByteArrayOutputStream bos = new ByteArrayOutputStream();
transformer.transform(new DOMSource(doc), new StreamResult(bos));
String xmlStr = bos.toString();
log.info(xmlStr);
oos.writeObject(xmlStr);
oos.flush();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if(oos != null) {
try {
oos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
即可