Question

First off all I didn’t find better title for my question, so please update if you have some words.

What I am doing :

In current I am sending two request for this purpose(One for user validation, another for data, if user is authorised). But I want to use single request.

What I want :

I will send a request as POST method to server where server will send a XML as response depends on my request.

For example :

• I am sending user and password to server.
• Server authenticate that user.

• If user authorised, server sends response xml as

  

• If authentication failed, server sends response as

Problem I faced :

I am not able to handle XML data, actually not identify the xml data.

I am using android.sax parser and I created two parser classes for both type of xml response, But how can I identify which parser class should I use depends on response?

Update :

Here is my actual xml

So how can I parse it, using single parser?

Answer 1

I would use a data structure which allows for the parser to see if it has failed or not.
Example:

public class XMLResponse {
 private boolean hasFailed;
 private Employee employee;
 public void setFailure(boolean in) {
    this.hasFailed=in;
 }
 public void setEmployee(Employee in) {
    this.employee=in;
 }
}

And in your parser, see if the response is false or not. This is based on the fact that your response from the webservice does not contain the response tag if its successful.

Here is an example of a parser, might need some tweaks before it can be used. It is only useful if you only get 1 employee in your response, otherwise you need to use a list.

public class XMLHandler extends DefaultHandler {
private XMLResponse myResponse;
private Employee employee;
public XMLResponse getParsedData() { 
    return this.myResponse;
}
@Override
public void startDocument() throws SAXException {
    myResponse = new XMLResponse();
    employee = new Employee();
}

@Override
public void startElement(String namespaceURI, String localName,

        String qName, Attributes atts) throws SAXException {
    buffer = new StringBuffer();
    if(localName.equals("employee")) {
        employee.setId(atts.getValue("id"));
    }
}
@Override

public void endElement(String namespaceURI, String localName, String qName)

throws SAXException {

    if(localName.equals("response")) {
        if(buffer.toString().contains("failure")) {
            myResponse.setFailure(true);
        }
    }
    else if(localName.equals("info")) {
        /*
         * This is only an example, could bee employee or whatever. You should use the startElement to get the tag. 
         */
    }
    else if(localName.equals("name")) {
        employee.setName(buffer.toString());
    }
    else if(localName.equals("age")) {
        employee.setAge(buffer.toString());
    }
    else if(localName.equals("employee")) {
        myResponse.setEmployee(employee);
    }


}

/** Gets be called on the following structure:

 * <tag>characters</tag> */


StringBuffer buffer;
@Override
public void characters(char ch[], int start, int length) {

    buffer.append(ch,start,length);
}