Question

Okay I’m really sorry if this question has been asked, but I can’t seem to find any good help on this.

I coded myself a little API for my android app using PHP and Codeigniter. It works through GET requests, so I’ll send it some info and it’ll return something. When I send it a login request, I want it to validate the user data, and if correct return the user’s credentials (uid, email, etc). All of this information can either be returned as formatted XML or a JSON array. My question is which would be easier to work with in Java, and can you help me with a quick example?

Any help is much appreciated.

EDIT:

Requested Code

                // Parse JSON array
                JSONObject obj = (JSONObject) JSONValue.parse(response);
                String uid = (String) obj.get("uid");
                String email = (String) obj.get("email");

Answer 1

From my experience, JSON is much easier to work with.

This is some data formatted in XML:

<book>
    <person>
      <first>Kiran</first>
      <last>Pai</last>
      <age>22</age>
    </person>
    <person>
      <first>Bill</first>
      <last>Gates</last>
      <age>46</age>
    </person>
    <person>
      <first>Steve</first>
      <last>Jobs</last>
      <age>40</age>
    </person>
</book>

Here is sample code to read the XML file:

import java.io.File;
import org.w3c.dom.Document;
import org.w3c.dom.*;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException; 

public class ReadAndPrintXMLFile{

    public static void main (String argv []){
    try {

            DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
            Document doc = docBuilder.parse (new File("book.xml"));

            // normalize text representation
            doc.getDocumentElement ().normalize ();
            System.out.println ("Root element of the doc is " + 
                 doc.getDocumentElement().getNodeName());


            NodeList listOfPersons = doc.getElementsByTagName("person");
            int totalPersons = listOfPersons.getLength();
            System.out.println("Total no of people : " + totalPersons);

            for(int s=0; s<listOfPersons.getLength() ; s++){


                Node firstPersonNode = listOfPersons.item(s);
                if(firstPersonNode.getNodeType() == Node.ELEMENT_NODE){


                    Element firstPersonElement = (Element)firstPersonNode;

                    //-------
                    NodeList firstNameList = firstPersonElement.getElementsByTagName("first");
                    Element firstNameElement = (Element)firstNameList.item(0);

                    NodeList textFNList = firstNameElement.getChildNodes();
                    System.out.println("First Name : " + 
                           ((Node)textFNList.item(0)).getNodeValue().trim());

                    //-------
                    NodeList lastNameList = firstPersonElement.getElementsByTagName("last");
                    Element lastNameElement = (Element)lastNameList.item(0);

                    NodeList textLNList = lastNameElement.getChildNodes();
                    System.out.println("Last Name : " + 
                           ((Node)textLNList.item(0)).getNodeValue().trim());

                    //----
                    NodeList ageList = firstPersonElement.getElementsByTagName("age");
                    Element ageElement = (Element)ageList.item(0);

                    NodeList textAgeList = ageElement.getChildNodes();
                    System.out.println("Age : " + 
                           ((Node)textAgeList.item(0)).getNodeValue().trim());

                    //------


                }//end of if clause


            }//end of for loop with s var


        }catch (SAXParseException err) {
        System.out.println ("** Parsing error" + ", line " 
             + err.getLineNumber () + ", uri " + err.getSystemId ());
        System.out.println(" " + err.getMessage ());

        }catch (SAXException e) {
        Exception x = e.getException ();
        ((x == null) ? e : x).printStackTrace ();

        }catch (Throwable t) {
        t.printStackTrace ();
        }
        //System.exit (0);

    }//end of main
}

And this is the same data formatted in JSON:

{"book":
    [ 
      {"person":
          {"last":"Pai","age":22,"first":"Kiran"}
      },
      {"person":
          {"last":"Gates","age":46,"first":"Bill"}
      },
      {"person":
          {"last":"Jobs","age":40,"first":"Steve"}
      }
    ]
}

And the sample code to read the JSON:

JSONObject obj = (JSONObject) JSONValue.parse(jsonString);
JSONArray arr = (JSONArray) obj.get("book");
for (int i = 0; i < arr.size(); i++) {
    JSONObject person = (JSONObject) arr.get(i);
    String first = (String) person.get("first");
    String last = (String) person.get("last");
    String age = (String) person.get("age");
    System.out.println("Person " + i +" : first = "+ first + ", last = " + last + ", age = " + age);
}

From the 2 piece of sample codes, you can see that JSON is much easier to read, write, and format.

XML is more commonly used as the industry standard for exchanging information, while JSON is commonly used to exchange information via REST-based APIs.