将信息写入到xml文件中的工具类
```
public void writeToXML(Document document) throws IOException{
FileOutputStream fos=new FileOutputStream("d://a.xml");
OutputStreamWriter osw=new OutputStreamWriter(fos, "utf-8");
XMLWriter writer=new XMLWriter(osw, OutputFormat.createPrettyPrint());
//将文档的内容写入到硬盘的xml中
writer.write(document);
//关流
writer.close();
osw.close();
fos.close();
}
```