dom4j乱码出现错误

package com.havenliu.blog;
 
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
 
public class Dom4jXmlOper {
 
 public static void createXml(File file)
 {
  XMLWriter writer = null;
  SAXReader reader = new SAXReader();
 
  OutputFormat format = OutputFormat.createPrettyPrint();
  format.setEncoding("utf-8");//设置XML文件的编码格式,如果有中文可设置为GBK或UTF-8
 
  Document _document = DocumentHelper.createDocument();
  Element _root = _document.addElement("userinfo");
  Element user = _root.addElement("user");
  user.addAttribute("id", "001");
  Element name = user.addElement("name");
  name.setText("张三");
  Element age = user.addElement("age");
  age.setText("28");
  Element sex = user.addElement("sex");
  sex.setText("男");
  Element email = user.addElement("email");
  email.setText("[e-mail]");
 
  //如果上面设置的xml编码类型为GBK，则应当用FileWriter来构建xml文件，否则会出现中文连码问题
  /*
   try {
   writer = new XMLWriter(new FileWriter(file), format);
  } catch (IOException e1) {
   e1.printStackTrace();
  }
  */
 
  //如果上面设置的xml编码类型为utf-8，则应当用FileOutputStream来构建xml文件，否则还是会出现乱码问题
  FileOutputStream fos = null;
  try {
   fos = new FileOutputStream(file);
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  }
  try {
   writer = new XMLWriter(fos, format);
  } catch (UnsupportedEncodingException e) {
   e.printStackTrace();
  }
  try {
   writer.write(_document);
   writer.close();
  } catch (IOException e) {
   e.printStackTrace();
  }
 }
 public static void main(String[] args)
 {
  String filePath = "d:\\temp\\user.xml";//生产的XML文件位置
  File file = new File(filePath);
  Dom4jXmlOper.createXml(file);
 }
 
}