java - Dom 设置元素错误

Question

我正在使用 Dom 创建 xml 文件，但我无法编写标签属性如下

<m:FC_TargetPath="SyndicationUpdated" m:FC_KeepInContent="false" rt:filterable="false">

当我设置属性时，我成功设置了名称和值，但使用 m: 或 rt: 前缀时出现异常。知道我该如何处理吗？

这是我使用的代码

ent.setAttribute("m:FC_TargetPath", "SyndicationUpdated");

异常(exception)是

'Namespace for prefix 'm' has not been declared.

Answer 1

示例程序如下:

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;

public class Dom
{
   public static void main( String[] args ) throws Throwable
   {
      DocumentBuilderFactory dbf  = DocumentBuilderFactory.newInstance();
      dbf.setNamespaceAware( true );

      DocumentBuilder db = dbf.newDocumentBuilder();
      Document doc = db.newDocument();

      Element root = doc.createElement( "root" );
      root.setAttribute( "xmlns:m" , "http://www.lfinance.fr/blog-rachat-credits" );
      root.setAttribute( "xmlns:rt", "http://www.lfinance.fr/forum-rachat-credits" );
      doc.appendChild( root );

      Element elt = doc.createElement( "simple" );
      elt.setAttribute( "m:FC_TargetPath"   , "false" );
      elt.setAttribute( "m:FC_KeepInContent", "false" );
      elt.setAttribute( "rt:filterable"     , "false" );

      root.appendChild( doc.createTextNode( "\n\t" ));
      root.appendChild( elt );
      root.appendChild( doc.createTextNode( "\n" ));
      TransformerFactory.newInstance().newTransformer().transform(
         new DOMSource( doc ),
         new StreamResult( System.out ));
   }
}

输出:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<root
    xmlns:m="http://www.lfinance.fr/blog-rachat-credits"
    xmlns:rt="http://www.lfinance.fr/forum-rachat-credits">
    <simple
        m:FC_KeepInContent="false"
        m:FC_TargetPath="false"
        rt:filterable="false" />
</root>