创建xml时，设置xml编码问题？？急急急

Java code

package com.Gavin.tools.xml;import org.dom4j.Document;import org.dom4j.DocumentHelper;import org.dom4j.Element;import org.dom4j.io.XMLWriter;import java.io.*;/*<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE catalog SYSTEM "file://c:/Dtds/catalog.dtd"><catalog> <!--An XML Catalog--><?target instruction?> <journal title="XML Zone" publisher="IBM developerWorks"><article level="Intermediate" date="December-2001"> <title>Java configuration with XML Schema</title><author>     <firstname>Marcello</firstname>     <lastname>Vitaletti</lastname> </author></article> </journal> ……//五本书</catalog> */public class XmlDom4J {    public void generateDocument() {                Document document = DocumentHelper.createDocument();                document.setXMLEncoding("GBK");//        System.out.println(document.getXMLEncoding());                Element root = document.addElement("catalog");                    root.addComment("An XML Catalog");                root.addProcessingInstruction("target", "text");                /**         * 为此         */        for(int i = 0; i < 5; i++) {            Element journal = root.addElement("journal");            journal.addAttribute("title", "XML Zone");            journal.addAttribute("publisher", "IBM developerWorks");                        Element article = journal.addElement("article");            article.addAttribute("level", "Intermediate");            article.addAttribute("date", "December-2001");                        Element title = article.addElement("title");            title.setText("Java configuration with XML Schema");                        Element author = article.addElement("author");                Element firstName = author.addElement("firstname");                firstName.setText("Marcello");                Element lastName = author.addElement("lastname");                lastName.setText("Vitaletti");                    }                document.addDocType("catalog", null, "file://c:/Dtds/catalog.dtd");                try {                        XMLWriter output = new XMLWriter(new FileWriter(new File("c:/catalog.xml")));            output.write(document);            output.close();                    } catch (IOException e) {            System.out.println(e.getMessage());        }    }    public static void main(String[] argv) {        XmlDom4J dom4j = new XmlDom4J();        dom4j.generateDocument();    }}

我想问的是：为什么我用document.setXMLEncoding("GBK");设置创建的xml编码确实不行的呢？请指教

[解决办法]

Java code

 
 OutputFormat format = OutputFormat.createPrettyPrint(); 
    format.setEncoding("GBK"); 
 XMLWriter output = new XMLWriter(new FileWriter(new File("c:/catalog.xml")),format); 
       output.write(document); 
 

[解决办法]

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Java code
OutputFormat format= OutputFormat.createPrettyPrint();
format.setEncoding("GBK");
XMLWriter output=new XMLWriter(new FileWriter(new File("c:/catalog.xml")),format);
output¡­