我先读取了xml配置文件再在里面修改了一些节点值再保存xml文档，就出现如下问题，
第一个是<?xml version="1.0" encoding="gb2312"?>中的encoding="utf-8"了
第二个是当我再次读这个xml文档时就报错了如下所示：
org.dom4j.DocumentException: Error on line 1 of document file:///C:/Documents and Settings/Administrator/jbproject/xml/src/jieMian/my_config.xml : 字符转换错误：“Unconvertible UTF-8 character beginning with 0xbc”（行号可能太小）。 Nested exception: 字符转换错误：“Unconvertible UTF-8 character beginning with 0xbc”（行号可能太小）。
at org.dom4j.io.SAXReader.read(SAXReader.java:482)
at org.dom4j.io.SAXReader.read(SAXReader.java:264)
at jieMian.xmlManager.getXmlConfig(xmlManager.java:88)
at jieMian.XmlManagerDialog.init(XmlManagerDialog.java:102)
at jieMian.XmlManagerDialog.<init>(XmlManagerDialog.java:36)
at jieMian.XmlManagerDialog.<init>(XmlManagerDialog.java:44)
at jieMian.XmlManagerDialog_butn2_actionAdapter$1.run(XmlManagerDialog.java:183)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:178)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:454)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)
Nested exception:
org.xml.sax.SAXParseException: 字符转换错误：“Unconvertible UTF-8 character beginning with 0xbc”（行号可能太小）。
at org.apache.crimson.parser.InputEntity.fatal(InputEntity.java:1100)
at org.apache.crimson.parser.InputEntity.fillbuf(InputEntity.java:1072)
at org.apache.crimson.parser.InputEntity.isXmlDeclOrTextDeclPrefix(InputEntity.java:914)
at org.apache.crimson.parser.Parser2.maybeXmlDecl(Parser2.java:1150)
at org.apache.crimson.parser.Parser2.parseInternal(Parser2.java:620)
at org.apache.crimson.parser.Parser2.parse(Parser2.java:333)
at org.apache.crimson.parser.XMLReaderImpl.parse(XMLReaderImpl.java:448)
at org.dom4j.io.SAXReader.read(SAXReader.java:465)
at org.dom4j.io.SAXReader.read(SAXReader.java:264)
at jieMian.xmlManager.getXmlConfig(xmlManager.java:88)
at jieMian.XmlManagerDialog.init(XmlManagerDialog.java:102)
at jieMian.XmlManagerDialog.<init>(XmlManagerDialog.java:36)
at jieMian.XmlManagerDialog.<init>(XmlManagerDialog.java:44)
at jieMian.XmlManagerDialog_butn2_actionAdapter$1.run(XmlManagerDialog.java:183)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:178)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:454)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)
有没有做过的，要怎么解决啊，急啊
[code="java"]
SAXReader reader=new SAXReader();
Document doc=reader.read(new File("F:\temp\test2.xml"));
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("gbk");//修改编码
XMLWriter writer=new XMLWriter(new FileOutputStream("F:\temp\test3.xml"),format);
writer.write(doc);
writer.close();
[/code]