Question

我遇到了这个Java函数来将XML节点转换为Java String表示：

private String nodeToString(Node node) {
StringWriter sw = new StringWriter();
try {
 Transformer t = TransformerFactory.newInstance().newTransformer();
 t.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
 t.setOutputProperty(OutputKeys.INDENT, "yes");
 t.transform(new DOMSource(node), new StreamResult(sw));
} catch (TransformerException te) {
 System.out.println("nodeToString Transformer Exception");
}
return sw.toString();
}

它看起来很简单，因为它希望输出字符串没有任何XML声明，并且它必须包含缩进。

但我想知道实际输出应该是什么，假设我有一个XML节点：

<p><media type="audio" id="au008093" rights="wbowned">
<title>Bee buzz</title>
</media>Most other kinds of bees live alone instead of in a colony. These bees make
        tunnels in wood or in the ground. The queen makes her own nest.</p>

我可以假设在应用上述转换后得到的字符串是：

"media type="audio" id="au008093" rights="wbowned" title Bee buzz title /media"

我想自己测试一下，但我不知道如何以这个函数实际需要的方式表示这个XML节点。

我有点困惑，并提前感谢慷慨的帮助。

Answer 1

所有重要的事情都已经说过了。我试着编译下面的代码。


import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.StringWriter;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
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.Node;

public class Test {

  public static void main(String[] args) throws Exception {

    String s = 
      "<p>" +
      "  <media type=\"audio\" id=\"au008093\" rights=\"wbowned\">" +
      "    <title>Bee buzz</title>" +
      "  " +
      "  Most other kinds of bees live alone instead of in a colony." +
      "  These bees make tunnels in wood or in the ground." +
      "  The queen makes her own nest." +
      "</p>";
    InputStream is = new ByteArrayInputStream(s.getBytes());

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();
    Document d = db.parse(is);

    Node rootElement = d.getDocumentElement();
    System.out.println(nodeToString(rootElement));

  }

  private static String nodeToString(Node node) {
    StringWriter sw = new StringWriter();
    try {
      Transformer t = TransformerFactory.newInstance().newTransformer();
      t.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
      t.setOutputProperty(OutputKeys.INDENT, "yes");
      t.transform(new DOMSource(node), new StreamResult(sw));
    } catch (TransformerException te) {
      System.out.println("nodeToString Transformer Exception");
    }
    return sw.toString();
  }

}

它产生了以下输出：


<p>  <media id="au008093" rights="wbowned" type="audio">    <title>Bee buzz</title>  </media>  Most other kinds of bees live alone instead of in a colony.  These bees make tunnels in wood or in the ground.  The queen makes her own nest.</p>

你可以自己进一步调整它。祝你好运！

Answer 2

您在DOM树中有XML重新表示例如，您已经打开了一个XML文件，并且已经在DOM解析器中传递了它因此，创建了内存中包含XML的DOM树现在，您只能通过遍历DOM树来访问XML信息但是，如果需要，可以使用DOM树的XML信息的String表示形式来进行转换发生这种情况是因为无法直接从DOM树获取String表示因此，例如，如果Node node传递nodeToString是XML文档的根元素，则结果是包含原始XML数据的String。
标签仍然存在。即您将拥有有效的XML表示。只有这一次才会在String变量中。

例如：

  DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
  DocumentBuilder parser = factory.newDocumentBuilder();
  Document xmlDoc = parser.parse(file);//file has the xml
  String xml = nodeToString(xmlDoc.getDocumentElement());//pass in the root
  //xml has the xml info. E.g no xml declaration. Add it
  xml = "<?xml version=\"1.0\" encoding=\"UTF-8\" ?> + xml;//bad to append this way...
  System.out.println("XML is:"+xml);

免责声明：甚至没有尝试编译代码。希望你明白你必须做什么

Java中的XML节点到字符串

2 个答案: