How to search an element in xml?

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devOn

I need to search for an element in an .xml file. It has this structure:

   <elements number="3">
     <contact>
       <name>PAUL</name>
       <code>A1</code>
     </contact>
     <contact>
       <name>LAURA</name>
       <code>A2</code>
     </contact>
     <contact>
       <name>JOHN</name>
       <code>A3</code>
     </contact>

My solution would be so:

public static String readContactsList(String nameContact) {
       XMLInputFactory xmlif = null;
       XMLStreamReader xmlr = null;

       String contacts = "contacts.xml";

       try {
           xmlif = XMLInputFactory.newInstance();
           xmlr = xmlif.createXMLStreamReader(contacts, new FileInputStream(contacts)); 
            while (xmlr.hasNext()) { 
                switch (xmlr.getEventType()) { 
                case XMLStreamConstants.START_DOCUMENT: 
                    System.out.println("Start Read Doc " + contacts); 
                    break;

                case XMLStreamConstants.START_ELEMENT: 
                    System.out.println("Tag " + xmlr.getLocalName());
                    for (int i = 0; i < xmlr.getAttributeCount(); i++)
                        System.out.printf(" => attribut %s->%s%n", xmlr1.getAttributeLocalName(i), xmlr.getAttributeValue(i)); 
                    break;
                case XMLStreamConstants.END_ELEMENT: 
                    System.out.println("END-Tag " + xmlr.getLocalName()); 
                    break;
                case XMLStreamConstants.COMMENT:
                    System.out.println("// comment " + xmlr.getText()); 
                    break; 
                case XMLStreamConstants.CHARACTERS: 
                    if (xmlr.getText().trim().length() > 0) 
                    if (!xmlr.getText().equals(nameContact)) {
                        xmlr.next();
                    }
                    else 
                    System.out.println("-> " + xmlr.getText()); 
                    break;
            }
               xmlr.next();
            }
       } 
       catch (Exception e) {
           System.out.println("reader initialization error");
           System.out.println(e.getMessage()); 
           }
       return contacts;
   }

This method receives a name of one contact (i.e. "LAURA") and it should return its code. What I miss is how to scroll the .xml file and how to access the different tags contents.

Thanks!

Jucaalpa

The following code (based on yours) should work, but be aware that if you switch the order of the tags <name> and <code> it will fail.

Also, be aware that you are not closing the stream. Just put a finally {xmlr.close();} that closes the stream.

   public static String readContactsList(String nameContact) {
        boolean match = false;   
        XMLInputFactory xmlif = null;
        XMLStreamReader xmlr = null;

        String contacts = "contacts.xml";

        try {
            xmlif = XMLInputFactory.newInstance();
            xmlr = xmlif.createXMLStreamReader(contacts, new FileInputStream(contacts)); 
            while (xmlr.hasNext()) { 
                switch (xmlr.getEventType()) { 
                case XMLStreamConstants.START_DOCUMENT: 
                    System.out.println("Start Read Doc " + contacts); 
                    break;

                case XMLStreamConstants.START_ELEMENT: 
                    System.out.println("Tag " + xmlr.getLocalName());    
                    for (int i = 0; i < xmlr.getAttributeCount(); i++)
                        System.out.printf(" => attribut %s->%s%n", xmlr.getAttributeLocalName(i), xmlr.getAttributeValue(i));
                    break;

                case XMLStreamConstants.END_ELEMENT: 
                    System.out.println("END-Tag " + xmlr.getLocalName()); 
                    break;

                case XMLStreamConstants.COMMENT:
                    System.out.println("// comment " + xmlr.getText()); 
                    break; 

                case XMLStreamConstants.CHARACTERS: 
                    if (xmlr.getText().trim().length() > 0) {
                        if (!xmlr.getText().equals(nameContact)) {
                            System.out.println("-> " + xmlr.getText());

                            if (match) {
                                return xmlr.getText();
                            }
                        }
                        else {
                            System.out.println("-> " + xmlr.getText());

                            //This is just in case the name and the code be the same
                            if (match) {
                                return xmlr.getText();
                            }

                            match = true;
                        }
                    }
                    break;
                }
                xmlr.next();
            }
        } 
        catch (Exception e) {
            System.out.println("reader initialization error");
            System.out.println(e.getMessage()); 
        }
        return contacts;
    }

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