解析具有相同父子标记的XML，然后最好使用SAX解析器将父标记的值链接到子标记

Question

I want to parse an XML having same parent-child tag and then link the value of parent tag to child tag using preferably SAX parser.

This is the XML file

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

<!-- Protocol header -->
<Protocol id="Diameter customer, country" spec="RFC3588" 
          name="Diameter" version="1.0" 
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
          xsi:noNamespaceSchemaLocation="file:/$CLASSES/cmg/stdapp/diameter/validation/Diameter_addon_schema.xsd">
 <!-- ACR declaration: Start -->
  <Request name="Start">
    <Condition key="Accounting-Record-Type" value="2"/>
    <AVP name="Node-Id" defaultValue="MTAS"/>
    <AVP name="Session-Id"/>
    <AVP name="Origin-Host"/>

        <AVP name="Subscription-Id">
            <AVP name="Subscription-Id-Type"/>
            <AVP name="Subscription-Id-Data"/>
        </AVP>
        <AVP name="IMS-Information">
            <AVP name="Event-Type">
                <AVP name="SIP-Method"/>
            </AVP>
            <AVP name="Role-of-Node"/>
         </AVP> 

  </Request>
<!---->


</Protocol>

In this example a tag with name AVP has child tag with same name AVP . I want to get the value of attribute name and then associate the value of parent to that of child. I use SAX parser for this but I'm unable to distinguish between parent and child but there is no distinction parent and child tags.

Java Code is

public void startElement(String s, String s1, String elementName, Attributes attributes) throws SAXException
{
    if (elementName.equalsIgnoreCase("AVP")) 
    {
        AVP_Tmp = new AVP();
        String nameValue = attributes.getValue("name");
         if (nameValue == null)
         {
             nameValue =attributes.getValue("value");
         }
         if (nameValue != null)
         {
             AVP_Tmp.set(nameValue,elementName,attributes);
         }
    }
}

@Override
public void endElement(String s, String s1, String element) throws SAXException 
{
    if (element.equals("AVP")) 
    {
        Object key = AVP_Tmp.tmpValue;
        Object value = AVP_Tmp.tmpValue;
        AVPL.put(key, value);                       
    }
}

The AVP_Tmp is a class whose set method is as follows:

public void set(String nameValue, String qName, Attributes attrs)//, int k)
{
    int len = attrs.getLength();
    tmpValue=qName + "-->" + nameValue;
    List list = new ArrayList();
    for (int i = 0; i < len; i++)
    {
        list.add(attrs.getQName(i));
    }
    Collections.sort(list);
    for (int i = 0; i < len; i++)
    {
         name1[i]= (Object)list.get(i);
         value1[i]=(attrs.getValue((String) list.get(i)));
        tmpValue=tmpValue+ "\n" +name1[i]+"="+value1[i];
    }
}

I currently have output as:

Node-Id
..
..
Subscription-Id
Subscription-Id-Type
IMS-Information
Event-Type
SIP-Method
..

I want the Output in format like:

Node-Id
..
..
..
Subscription-Id#Subscription-Id-Type
IMS-Information#Event-Type#SIP-Method
..

Answer 1

When I got your goals right, I would do it the way, that you build the "AVP-Structure" and afterwards extract the needed output.

So when a new AVP starts it will look something like that (just in pseudo-code):

if (parent == null){
   avpTemp = new AVP();
   parent = avpTemp;
} else {avpTemp = new AVP(parent); }

After the parsing, you have got the hierarchy and build the structe/result as you want it.