使用 Java 解析 XML 并获取元素值和属性值

XML parsing using Java with getting element values and attribute values

提问by user1036204

i have an XML file and the elements also have attributes. I have a simple java file which is parsing and printing values of elements in a text file but not element attribute values. Please can you help in getting the attributes values also to be printed. I am pasting the code below: --------employees.xml file-----------

我有一个 XML 文件，元素也有属性。我有一个简单的 java 文件，它解析和打印文本文件中元素的值，而不是元素属性值。请您帮助获取也要打印的属性值。我粘贴下面的代码：--------employees.xml 文件-----------

<?xml version="1.0" encoding="UTF-8"?>

<Personnel>

  <Employee type="permanent">
    <Name>Seagull</Name>
    <Id>3674</Id>
    <Age>34</Age>
   </Employee>

  <Employee type="contract">
    <Name>Robin</Name>
    <Id>3675</Id>
    <Age>25</Age>
</Employee>

  <Employee type="permanent">
    <Name>Crow</Name>
    <Id>3676</Id>
    <Age>28</Age>
  </Employee>

</Personnel>

----------------------------StoreData.java-----------------------------------------

---------------------------StoreData.java------------------- ---------------

import java.io.*;
import org.w3c.dom.*;
import org.xml.sax.*;
import javax.xml.parsers.*;
import javax.xml.transform.*; 
import javax.xml.transform.dom.DOMSource; 
import javax.xml.transform.stream.StreamResult;

public class StoreData{
static public void main(String[] arg) {
    try{
        BufferedReader bf = new BufferedReader(new       InputStreamReader(System.in));
        System.out.print("Enter XML file name: ");
        String xmlFile = bf.readLine();
        File file = new File(xmlFile);
            if (file.exists()){
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document doc = builder.parse(xmlFile);
                        //Create transformer
            Transformer tFormer = TransformerFactory.newInstance().newTransformer();
                     //Output Types (text/xml/html)
            tFormer.setOutputProperty(OutputKeys.METHOD, "text");
//              Write the document to a file
            Source source = new DOMSource(doc);
//              Create?File??to?view?your?xml?data?as (vk.txt/vk.doc/vk.xls/vk.shtml/vk.html)
            Result result = new StreamResult(new File("file.txt"));
            tFormer.transform(source, result);
            System.out.println("File creation successfully!");
        }
        else{
            System.out.println("File not found!");
        }
    }
    catch (Exception e){
        System.err.println(e);
        System.exit(0);
    }  
} }

---

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回答by stzoannos

Since you are using org.w3c.dom you might use the following:

由于您使用的是 org.w3c.dom，因此您可能会使用以下内容：

        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        InputSource is = new InputSource(new StringReader(xmlFile));
        Document doc = builder.parse(is);

        NodeList nodeList = doc.getElementsByTagName("Employee");

        for (int i = 0; i < nodeList.getLength(); i++) {                
            Node node = nodeList.item(i);

            if (node.hasAttributes()) {
                Attr attr = (Attr) node.getAttributes().getNamedItem("type");
                if (attr != null) {
                    String attribute= attr.getValue();                      
                    System.out.println("attribute: " + attribute);                      
                }
            }
        }

回答by Joop Eggen

What you are using is an XSLT transformation which by default transforms to element texts.

您使用的是 XSLT 转换，默认情况下会转换为元素文本。

Using the same technique, one needs an own "stylesheet":

使用相同的技术，需要一个自己的“样式表”：

    InputStream xsltIn = StoreData.class.getResourceAsStream("/employees.xslt");
    StreamSource xslt = new StreamSource(xsltIn);
    ///StreamSource xslt = new StreamSource(".../employees.xslt");

    Transformer tFormer = TransformerFactory.newInstance().newTransformer(xslt);

Above I used a resource, not a file system File, so it is packed with the application.

上面我使用了一个资源，而不是文件系统文件，所以它与应用程序一起打包。

employees.xslt:

员工.xslt：

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

    <xsl:template match="/Personnel">
Personnel:
        <xsl:apply-templates select="./*"/>
End personnel.
    </xsl:template>

    <xsl:template match="Employee">
* Employee:<xsl:apply-templates select="./@*|./*"/>

    </xsl:template>

    <xsl:template match="Name|Id|Age|@type">
  - <xsl:value-of select="name()"/>: <xsl:value-of select="."/>
    </xsl:template>
</xsl:stylesheet> 

Which would produce:

这将产生：

Personnel:

* Employee:
  - type: permanent
  - Name: Seagull
  - Id: 3674
  - Age: 34
* Employee:
  - type: contract
  - Name: Robin
  - Id: 3675
  - Age: 25
* Employee:
  - type: permanent
  - Name: Crow
  - Id: 3676
  - Age: 28
End personnel.