Question

private void dislpay() {
        try {   
            File fXmlFile = new File("/data/data/com.example.addnode/Add.xml");
            DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
            Document doc = dBuilder.parse(fXmlFile);
            doc.getDocumentElement().normalize();
            System.out.println("Root element :" + doc.getDocumentElement().getNodeName());
            NodeList nList = doc.getElementsByTagName("details");
            for (int temp = 0; temp <= nList.getLength(); temp++) {
                Node nNode = nList.item(temp);
                if (nNode.getNodeType() == Node.ELEMENT_NODE) {
                    Element eElement = (Element) nNode;

                    String a=eElement.getElementsByTagName("firstname").item(temp).getTextContent().toString();
                    String b=eElement.getElementsByTagName("lastname").item(temp).getTextContent().toString();
                    String c=eElement.getElementsByTagName("nickname").item(temp).getTextContent().toString();

                    System.out.println(a);
                    System.out.println(b);
                    System.out.println(c);
                }
            }
            } catch (Exception e) {
            e.printStackTrace();
            }

XML

 <?xml version="1.0" encoding="UTF-8"?>
    <user>
       <details id="1">
         <firstname>JOHN</firstname>
         <lastname>R</lastname>
         <nickname>JJ</nickname>
       </details>
       <details>
         <firstname>NOMAN</firstname>
         <lastname>K</lastname>
         <nickname>NK</nickname>
       </details>    
    </user>

预期产出：

JOHN R JJ
NOMAN K NK

当前输出为：

JOHN R JJ

我想显示子节点的所有值（详细信息），但是当我执行应用程序时，它只显示前三个值而不是全部。我正在学习XML，所以我对XML知之甚少。所以请指导我。

Answer 1

在现有代码中，纠正错误....，

//Remove = otherwise loop will run 3 times and you will get null pointer exception
for (int temp = 0; temp < nList.getLength(); temp++)

// Replace temp with 0 here because temp is increasing with your for loop and this is first node of this element always

                String a=eElement.getElementsByTagName("firstname").item(0).getTextContent().toString();
                String b=eElement.getElementsByTagName("lastname").item(0).getTextContent().toString();
                String c=eElement.getElementsByTagName("nickname").item(0).getTextContent().toString();

为了您的方便，我自己准备了这个DOM解析器，使用递归来解析你的xml，而不需要知道单个标记。如果存在，它将按顺序为您提供每个节点的文本内容。您可以删除以下代码中的注释部分以获取节点名称。希望它会有所帮助。

    import java.io.BufferedWriter;
    import java.io.File;  
    import java.io.FileInputStream;  
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.OutputStreamWriter;

     import javax.xml.parsers.DocumentBuilder;  
     import javax.xml.parsers.DocumentBuilderFactory;  
     import org.w3c.dom.Document;  
     import org.w3c.dom.Node;  
     import org.w3c.dom.NodeList;  



    public class RecDOMP {


    public static void main(String[] args) throws Exception{
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();  
            dbf.setValidating(false); 
            DocumentBuilder db = dbf.newDocumentBuilder();   

    // replace following  path with your input xml path  
             Document doc = db.parse(new FileInputStream(new File  ("D:\\ambuj\\ATT\\apip\\APIP_New.xml")));  

    // replace following  path with your output xml path 
             File OutputDOM = new File("D:\\ambuj\\ATT\\apip\\outapip1.txt");
                FileOutputStream fostream = new FileOutputStream(OutputDOM);
                OutputStreamWriter oswriter = new OutputStreamWriter (fostream);
                BufferedWriter bwriter = new BufferedWriter(oswriter);

                // if file doesnt exists, then create it
                if (!OutputDOM.exists()) {
                    OutputDOM.createNewFile();}


                visitRecursively(doc,bwriter);
                bwriter.close(); oswriter.close(); fostream.close();

                System.out.println("Done");
    }
    public static void visitRecursively(Node node, BufferedWriter bw) throws IOException{  

                 // get all child nodes  
             NodeList list = node.getChildNodes();                                  
             for (int i=0; i<list.getLength(); i++) {          
                     // get child node              
           Node childNode = list.item(i);  
           if (childNode.getNodeType() == Node.TEXT_NODE)
           {
       //System.out.println("Found Node: " + childNode.getNodeName()           
        //   + " - with value: " + childNode.getNodeValue()+" Node type:"+childNode.getNodeType()); 

       String nodeValue= childNode.getNodeValue();
       nodeValue=nodeValue.replace("\n","").replaceAll("\\s","");
       if (!nodeValue.isEmpty())
       {
           System.out.println(nodeValue);
           bw.write(nodeValue);
           bw.newLine();
       }
           }
           visitRecursively(childNode,bw);  

                }         

         }  

    }

检索子节点值

1 个答案: