Android - How to handle Webservice in XML?

Question

I have a sample XML file as below:

 <?xml version="1.0"?>
  <h:html xmlns="http://www.w3.org/2002/xforms" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:h="http://www.w3.org/1999/xhtml" xmlns:jr="http://openrosa.org/javarosa" xmlns:orx="http://openrosa.org/xforms/" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
 <h:head>
<h:title>tutorial</h:title>
<model>
  <instance>
    <tutorial id="tutorial">
      <name/>
      <age/>
      <gender/>
      <photo/>
      <date/>
      <location/>
      <thanks/>
      <start/>
      <end/>
      <today/>
      <deviceid/>
      <subscriberid/>
      <simserial/>
      <phonenumber/>
      <meta>
        <instanceID/>
      </meta>
    </tutorial>
  </instance>
  <bind nodeset="/tutorial/name" required="true()" type="string"/>
  <bind constraint=". &gt; 0 and . &lt; 120" jr:constraintMsg="That's not a valid age!" nodeset="/tutorial/age" required="true()" type="int"/>
  <bind nodeset="/tutorial/gender" type="select1"/>
  <bind nodeset="/tutorial/photo" type="binary"/>
  <bind nodeset="/tutorial/date" type="date"/>
  <bind nodeset="/tutorial/location" type="geopoint"/>
  <bind nodeset="/tutorial/thanks" readonly="true()" type="string"/>
  <bind jr:preload="timestamp" jr:preloadParams="start" nodeset="/tutorial/start" type="dateTime"/>
  <bind jr:preload="timestamp" jr:preloadParams="end" nodeset="/tutorial/end" type="dateTime"/>
  <bind jr:preload="date" jr:preloadParams="today" nodeset="/tutorial/today" type="date"/>
  <bind jr:preload="property" jr:preloadParams="deviceid" nodeset="/tutorial/deviceid" type="string"/>
  <bind jr:preload="property" jr:preloadParams="subscriberid" nodeset="/tutorial/subscriberid" type="string"/>
  <bind jr:preload="property" jr:preloadParams="deviceid" nodeset="/tutorial/simserial" type="string"/>
  <bind jr:preload="property" jr:preloadParams="phonenumber" nodeset="/tutorial/phonenumber" type="string"/>
  <bind calculate="concat('uuid:', uuid())" nodeset="/tutorial/meta/instanceID" readonly="true()" type="string"/>
</model>
</h:head>
<h:body>
<input ref="/tutorial/name">
  <label>What's your name?</label>
</input>
<input ref="/tutorial/age">
  <label>How old are you?</label>
</input>
<select1 ref="/tutorial/gender">
  <label>Gender</label>
  <item>
    <label>Male</label>
    <value>male</value>
  </item>
  <item>
    <label>Female</label>
    <value>female</value>
  </item>
</select1>
<upload mediatype="image/*" ref="/tutorial/photo">
  <label>Please Take a picture</label>
</upload>
<input ref="/tutorial/date">
  <label>Date</label>
</input>
<input ref="/tutorial/location">
  <label>Where are you?</label>
  <hint>You need to be outside for your GPS to work.</hint>
</input>
<input ref="/tutorial/thanks">
  <label>Thanks for your time <output value="/tutorial/name"/>!</label>
</input>
</h:body>
</h:html>

Now i want to fill <input ref="/tutorial/name"> with the data coming as a response from the web service? I have a web service which is giving the response correctly. Please help me....

Answer 1

To Replace <input ref="/tutorial/name"> tag. You have to follow this three steps.

1) Find <input ref="/tutorial/name"> TAG in the XML file.

2) Do update, delete , replace whatever functionality you want.

3) Write the content into the XML file

Step 1: Find Node:

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder db = factory.newDocumentBuilder();
Document dom = db.parse(FILE);
Element root = dom.getDocumentElement();

//get node-list,
NodeList inputNodeList = root.getElementsByTagName("input");

//iterate over all input node to find the desired one.
for(int i=0;i<inputNodeList.length();i++){
  Node inputNode = inputNodeList.item(i); //get a single node.
  String refStr = inputNode.getAttributes().getNamedItem("ref").getNodeValue();
  if(refStr.compareTo("/tutorial/name")==0){

     // Bingo, You have find the NODE. Now you can do any operations like delete, edit whatever you want.
   }
}

Step 2 : Do Replace operation.

you can delete the node using.

inputNode.getParentNode().removeChild(inputNode);

If you want to replace the node, have look at replaceChild() method.

Basic idea is,

• Create a Node from the response string. Refer this link for creating xml node from the string.
• Find parent of the inputNode using inputNode.getParentNode().
• Use replaceChild() method to replace old node with the new node.

For an example of replaceChild() method you can refer this link. Here is a nice tutorial for modifying XML file using DOM parser - TUTORIAL.

Step 3 : Write the content into the XML file.

TransformerFactory transformerFactory = TransformerFactory.newInstance();  
Transformer transformer = transformerFactory.newTransformer();   
DOMSource source = new DOMSource(doc);   
StreamResult result = new StreamResult(selectedFile); 
transformer.transform(source, result); 

Hope, this will give you some hint about achieving your desired task.

Answer 2

I am using SAXParser to handle the xml parsing in my app.

try {
        /**
         * Create a new instance of the SAX parser
         **/
        SAXParserFactory saxPF = SAXParserFactory.newInstance();
        SAXParser saxP = saxPF.newSAXParser();
        XMLReader xmlR = saxP.getXMLReader();
        URL url = new URL("http:Your URL"); // URL of the XML
        XMLHandler myXMLHandler = new XMLHandler();
        xmlR.setContentHandler(myXMLHandler);
        xmlR.parse(new InputSource(url.openStream()));

    } catch (Exception e) {
        e.printStackTrace();
    }

Also here is a good tutorial on this: http://mobile.tutsplus.com/tutorials/android/android-sdk-build-a-simple-sax-parser/