利用javax.xml.transform.*;transform xml时候的xsl:output@encoding问题

首先写了几个转换函数：    public static boolean saveNodeToStream(Node node, OutputStream out){        try {
            
            Source source = new DOMSource(node);            Result result = new StreamResult(out);            
            Transformer xformer = TransformerFactory.newInstance().newTransformer();               xformer.transform(source, result);        } catch (Exception e){
            return false;
        }
        return true;
    }    public static String saveNodeToString(Node node){
        ByteArrayOutputStream bout=new ByteArrayOutputStream();
        if(!saveNodeToStream(node,bout)){
            Utils.CloseStream(bout);
            return null;
        }
        try{
            bout.flush();
            String r=bout.toString();
            bout.close();
            return r;
        }catch(IOException e){
            return null;
        }    }     public static Document transform(String xml_filename, String xsl_filename) {
            try {
                // Create transformer factory
                TransformerFactory factory = TransformerFactory.newInstance();                // Use the factory to create a template containing the xsl file
                Templates template = factory.newTemplates(new StreamSource(
                    new FileInputStream(xsl_filename)));                // Use the template to create a transformer
                Transformer xformer = template.newTransformer();                // Prepare the input file
                Source source = new StreamSource(new FileInputStream(xml_filename));                // Create a new document to hold the results
                DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
                Document doc = builder.newDocument();
                Result result = new DOMResult(doc);
                
                // Apply the xsl file to the source file and create the DOM tree
                xformer.transform(source, result);
                return doc;
            } catch (ParserConfigurationException e) {
                // An error occurred while creating an empty DOM document
            } catch (FileNotFoundException e) {
            } catch (TransformerConfigurationException e) {
                // An error occurred in the XSL file
            } catch (TransformerException e) {
                // An error occurred while applying the XSL file
            }
            return null;
    }
然后用以下代码测试：
    public static void main(String[] args) {
        String xml="c:/test/1.xml";
        String xsl="c:/test/pi.xsl";
                Document doc=XMLUtils.transform(xml,xsl);
        if(doc==null)return;
        
        System.out.print(XMLUtils.saveNodeToString(doc));
    }其中,1.xml如下：<?xml version='1.0' encoding='gb2312' ?>
<customers>
<customer>
   <name>我</name>
   <address>123 Elm St.</address>
   <phone>(123) 456-7890</phone>
</customer>
<customer>
   <name>Amy Jones</name>
   <address>456 Oak Ave.</address>
   <phone>(156) 789-0123</phone>
</customer>
</customers>pi.xsl如下：<?xml version='1.0' encoding="gb2312"?>
<xsl:stylesheet version="1.0"
      xmlns:xsl="http://www.w3.org/1999/XSL/Transform" ><xsl:output method='xml' version='1.0' encoding="gb2312"/> <<===========注意这里是gb2312
<xsl:template match="/">  <xsl:apply-templates />
</xsl:template>  <xsl:template match="@* | *">
    <xsl:copy>
      <xsl:apply-templates select="@* | node()"/>
    </xsl:copy>
  </xsl:template></xsl:stylesheet>／／／／／／／／／／／／／／／／／／／／／／而产生的结果如下：<?xml version="1.0" encoding="UTF-8"?> <<=========注意这里是utf-8而不是gb2312<customers><customer>   <name>鎴?/name> <<==========注意这里是"乱码"   <address>123 Elm St.</address>   <phone>(123) 456-7890</phone></customer><customer>   <name>Amy Jones</name>   <address>456 Oak Ave.</address>   <phone>(156) 789-0123</phone></customer></customers>////////////////////////////////为什么在xsl:output 的encoding里面指定了编码方式，生成的xml文件编码方式却变成了utf-8 ?????????????????????????困惑不已！！！！！！！！！！！！！1