VTD XML parsing. Get value based on tag and attribute

Question

I have a bit complex XML.

<?xml version="1.0" encoding="UTF-8"?><test:mark><parent parent_id="1"><child child_id="1_1">11Value</child><child child_id="1_2">12Value</child><child child_id="1_3">13Value</child></parent><other other_id="1"><inner>1233</inner></other></test:mark>

I am very new to VTD and now instead of parsing entire XML by DOM or SAX I want to get the value of <child child_id="1_2">

Can anyone suggest what XPATH expression can be used. Thanks in advance for the help. Other better options are welcome as well.

Below is what I am doing. And is not working!!

VTDGen vtdGen = new VTDGen();
        vtdGen.parseFile("E:/JavaProjects/SampleTestingFiles/SampleXML.xml", true);

        VTDNav vtdNav = vtdGen.getNav();
        AutoPilot autoPilot = new AutoPilot(vtdNav);

        try {
            autoPilot.selectXPath("//parent/child[@child_id='1_2']");
            if(autoPilot.evalXPathToBoolean()) {
                int token = autoPilot.evalXPath();
                if(token != -1) {
                    String value = vtdNav.toNormalizedString(token);
                    System.out.println("The value is - " + value);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

If I do something like autoPilot.selectXPath("//parent/child[@child_id]");. It selects some of the tags with attribute @child_id but not all.

Any help is much appreciated even the documentation on how we should give XPATHs can help.

Answer 1

Your XPath evaluation logic not correct (your xpath expression seems ok)...

if(autoPilot.evalXPathToBoolean()) {
                int token = autoPilot.evalXPath();
                if(token != -1) {
                    String value = vtdNav.toNormalizedString(token);
                    System.out.println("The value is - " + value);
                }
            }

should be rewritten as

int i=-1;
while((i=autoPilot.evalXPath())!=-1){
              String value = vtdNav.toNormalizedString(i);
              System.out.println("The value is - " + value);
}