使用SAX解析Java中的自定义XML响应

Question

I am trying to parse response similar to xml style using SAX.Below is my response format.

    <Subscriber id="11005632326">
<info name="info1" value="12012012010"/>
<info name="info2" value="11005632326"/>
<info name="info3" value="12312321321"/>
<info name="info4" value="hJLDos"/>
<info name="info5" value="Apple A1778/Apple iPhone 7"/>
<info name="group" value="above"/>
<info name="language" value="en"/>
<info name="lastotatime" value=""/>
<info name="detected" value="2017-01-14 23:22:45.158365"/>
</Subscriber>

Here I am trying to get the values of each value in the tag,like info1.value,info2.value,etc.

I have tried with following code

File fXmlFile = new File("c:/temp/admresp.xml");
    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder  dBuilder;
    try {
         dBuilder = dbFactory.newDocumentBuilder();
        Document doc = dBuilder.parse(fXmlFile);
        doc.getDocumentElement().normalize();

        System.out.println("Root element :" + doc.getDocumentElement().getNodeName());
        NodeList nList = doc.getElementsByTagName("info");

        System.out.println("----------------------------");

        for (int temp = 0; temp < nList.getLength(); temp++) {

            Node nNode = nList.item(temp);

            System.out.println("\nCurrent Element :" + nNode.getNodeName()+"\n node value"+nNode.getNodeValue());
            nNode.getNodeValue();

            if (nNode.getNodeType() == Node.ELEMENT_NODE) {

                Element eElement = (Element) nNode;

                System.out.println("info1: " + eElement.getAttribute("info1"));
            }
        }

    } catch (SAXException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ParserConfigurationException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

Can somone help me here as I am getting null in info1 value in the output

Current Element :info
node valuenull
info1 : 

Answer 1

I believe the getElementsByTagName method only returns elements directly under the the element you call it on. So you will want to use it on the root element instead of document. You will also need to be careful of things like whitespace/tabs/newlines.

This way of iterating through the document works for me.

        Node child = doc.getDocumentElement().getFirstChild();
        while((child = child.getNextSibling()) != null) {
            if(child instanceof Element) {
                String name = ((Element) child).getAttribute("name");
                String value = ((Element) child).getAttribute("value");
                System.out.println("name: " + name + ", value: " + value);
            }
        }

Answer 2

With below code I am able to parse it getting the attribute of tagName.Values are inserting into a hashmap in my case.

//Using factory get an instance of document builder
        DocumentBuilder db = dbf.newDocumentBuilder();
        //parse using builder to get DOM representation of the XML file
        dom=db.parse(new ByteArrayInputStream(xmlFile));
        Map<String,String> attrMap=new HashMap<String,String>();
        Element docEle = dom.getDocumentElement();
        //get a nodelist of      elements
        NodeList nl = docEle.getElementsByTagName("info");
        if(nl != null && nl.getLength() > 0) {
            for(int i = 0 ; i < nl.getLength();i++) {

                //get the info element
                Element el = (Element)nl.item(i);

                attrMap.put(el.getAttribute("name"), el.getAttribute("value"));
            }
        }