java - 使用 Java 删除 XML 字段中的空格

Question

我在删除 xml 数据值字段中的空格时遇到了问题。

例如:

输入

<?xml version="1.0"?>
<ns:myOrder xmlns:ns="http://w3schools.com/BusinessDocument" xmlns:ct="http://something.com/CommonTypes">
  <MessageHeader>
     <ct:ID>i7                           </ct:ID>
     <ct:ID>i7                           </ct:ID>
     <ct:ID>i7                           </ct:ID>
     <ct:ID>i7                           </ct:ID>
     <ct:Name> Company Name           </ct:Name>
 </MessageHeader>
</ns:myOrder>

预期输出:

<?xml version="1.0"?>
  <ns:myOrder xmlns:ns="http://w3schools.com/BusinessDocument" xmlns:ct="http://something.com/CommonTypes">
    <MessageHeader>
       <ct:ID>i7</ct:ID>
       <ct:ID>i7</ct:ID>
       <ct:ID>i7</ct:ID>
       <ct:ID>i7</ct:ID>
       <ct:Name>Company Name</ct:Name>
    </MessageHeader>
  </ns:myOrder>

我试过下面的代码

public static String getTrimmedXML(String rawXMLFilename) throws Exception
     {
          BufferedReader in = new BufferedReader(new FileReader(rawXMLFilename));
     String str;
     String trimmedXML = null;     
     while ((str = in.readLine()) != null) 
     {
          String str1 = str;
          if (str1.length()>0) 
          {
               str1 = str1.trim();
               if(str1.charAt(str1.length()-1) == '>')
               {
                    trimmedXML = trimmedXML + str.trim();
               }
               else
               {
                    trimmedXML = trimmedXML + str;
               }
          }
     }     
     in.close();
     return trimmedXML.substring(4);
     }

我无法删除这些空格。请让我知道哪里出错了

问候，莫尼什

Answer 1

您可能不想使用替换或全部替换，因为那样它会替换您的 xml 数据中的所有空格。如果要修剪 xml 内容的开始/结束，要么要解析整个 xml，要么使用 xpath 并将其转换回字符串。使用下面的代码。

public static String getTrimmedXML(String rawXMLFilename, String tagName) throws Exception {
    // Create xml document object
    BufferedReader in = new BufferedReader(new FileReader(rawXMLFilename));
    InputSource source = new InputSource(in);
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();
    Document document = db.parse(source);
    XPathFactory xpathFactory = XPathFactory.newInstance();
    XPath xpath = xpathFactory.newXPath();

    // Path to the node that you want to trim
    NodeList nodeList = (NodeList) xpath.compile("//*[name()='" + tagName + "']").evaluate(document, XPathConstants.NODESET);
    for (int index = 0; index < nodeList.getLength(); index++) { // Loop through all nodes that match the xpath
        Node node = nodeList.item(index);
        String newTextContent = node.getTextContent().trim(); // Actual trim process
        node.setTextContent(newTextContent);
    }

    // Transform back the document to string format.
    TransformerFactory tf = TransformerFactory.newInstance();
    Transformer transformer = tf.newTransformer();
    transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
    StringWriter writer = new StringWriter();
    transformer.transform(new DOMSource(document), new StreamResult(writer));
    String output = writer.getBuffer().toString().replaceAll("\n|\r", "");
    return output;
}