dom4j构造XML时产生中文乱码

格式化输出XML文件时候，如果输出UTF-8格式
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("UTF-8");

try {
XMLWriter writer = new XMLWriter(new FileOutputStream(new File(filename)),format);
writer.write(document);
writer.close();
return 1;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
必须用FileOutputStream构建输出流