One of the most powerful aspects of any mobile application for a 3G phone is that it can connect to the Internet. By connecting to the Internet the application can offer much more value to the user since it becomes an interface for a web-based component, e.g. using Twitter’s API to create a Twitter application so that you can get your Twitter updates without having to open the mobile browser. The most common way of interfacing with a web-based component is by using web services in XML format.
While trying to developer my own app which reads a web service from my own server, I ran into a lot of difficulties in implementing the client that consumes the web service. Android does not have libraries for XPath handling of XML documents, so it makes deciphering XML data a little bit more difficult. From what I’ve read online the Android team is currently working on including such libraries in future versions.
After some digging around I found an amazing link that shows different methods for consuming an XML file in Android and parsing through it without the use of XPaths. The link is this: Working with XML on Android. To start off, this link is an absolute must-read. Everything that I am going to write in my post here relates to this link. The code offered on that webpage uses polymorphism to show you 4 different methods of working with XML data. It provides a fully-functional Android application and all the source code for it. The source code can be found here: AndroidXML.zip.
My post today will concentrate on how to customize the code from the application in the above link, in order to read and parse your own XML data. If you are a Java pro, you might not need this post. My Java is a little rusty, so I needed some time to figure out exactly what I had to change and where in order to get this to work with my own web service XML. Now that I’ve figured it out, I thought I’d share it. In my next post I will give the simplified version of this code – where there is no polymorphism, and thus there are only the minimum number of classes needed to implement this XML-reading solution. I can’t offer this simplified code right now – because I haven’t coded it yet :).
So until I post the simplified source code for working with XML data in Android, here are some tips on getting through the larger polymorphism-based source code and customizing it for your own XML data:
1. First off, read over the link Working with XML on Android as much as you can.
2. Download the source code for the Android application that they offer: AndroidXML.zip.
3. Import the project into your Eclipse workspace by right-clicking in Project Explorer and selecting “Import”.
4. Select “Existing Projects into Workspace”
5. Browse to the directory where you extracted the ZIP file with the source code and then click on the Next buttons to finish off the wizard. The project is called “AndroidXml”.
6. You will now see the project in your workspace:
7. Here is a quick breakdown of what some of those Java classes do:
- MessageList.java is the main activity that gets started. It lists the items from the XML data using a ListActivity. In this project the items come from an RSS feed.
- FeedParser.java, FeedParserFactory.java, BaseFeedParser.java, RSSHandler.hava are all classes that this particular example uses to set the framework for polymorphism.
- This example uses 4 methods for grabbing the XML data and reading it.The 4 methods that this example uses are:
1. AndroidSaxFeedParser.java (the default)
2. DomFeedParser.java
3. SaxFeedParser.java
4. XmlPullFeedParser.java
These 4 classes all extend BaseFeedParser.java.
8. In order to customize this for your own XML file you need to edit the following places (assuming you are using AndroidSaxFeedParser, which is the default):
- FeedParserFactory.java: you need to change the URL location of the web service or XML document in the global variable here:
static String feedUrl = "http://www.androidster.com/android_news.rss";
- AndroidSaxFeedParser.java: you need to change the root node of your XML document. This is stored in the String called RSS.
static final String RSS = "RootNode";
- BaseFeedParser.java: you need to change this class according to the nodes that your XML document has.
The nodes CHANNEL and ITEM refer to the nodes <Channel> and <Item> in the RSS feed that this example uses. You need to change them to mimic your nodes from your XML document:
static final String CHANNEL = "channel"; static final String ITEM = "item";
The other constants that are declared refer to the nodes for each repeating item.
static final String PUB_DATE = "pubDate"; static final String DESCRIPTION = "description"; static final String LINK = "link"; static final String TITLE = "title";
For this particular example, since an RSS feed XML document is used, it has repeating nodes for <Description>, <Link>, <Title>, <PubDate>. You need to change this structure to mimic your structure.
Note: Remember that if you change the name of the constants (as opposed to the value of the constants), you will need to change other classes which call these constants.
- If you change the names of the constants, you will have to update AndroidSaxFeedParser.java in this section:
item.getChild(TITLE).setEndTextElementListener(new EndTextElementListener(){ public void end(String body) { currentMessage.setTitle(body); } }); item.getChild(LINK).setEndTextElementListener(new EndTextElementListener(){ public void end(String body) { currentMessage.setLink(body); } }); item.getChild(DESCRIPTION).setEndTextElementListener(new EndTextElementListener(){ public void end(String body) { currentMessage.setDescription(body); } }); item.getChild(PUB_DATE).setEndTextElementListener(new EndTextElementListener(){ public void end(String body) { currentMessage.setDate(body); } });
As you can see this section is hardcoded for the 4 nodes that are expected in this XML document (TITLE, LINK, DESCRIPTION, PUB_DATE). You will need to change this section and hardcode this for your own nodes.
- If you change the names of the higher-level nodes, i.e. <Channel> and <Item>, then you need to update the following section of AndroidSaxFeedParser.java:
Element itemlist = root.getChild(CHANNEL); Element item = itemlist.getChild(ITEM);
And that is all. The customized code will use the AndroidSaxParser implementation of an XML Parser, it will go to the URL you provided in FeedParserFactory.java, and it will iterate through the updated nodes as you have labeled them in BaseFeedParser.java and AndroidSaxFeedParser.java.
In my next post I will provide a simplified version of this code, which does not use polymorphism. It will (hopefully) use the minimum required classes to get XML data and parse it.
October 2, 2009 at 07:32
Hi, This is a great manual, congratulations. I have a problem.
In MessageList.java I would like pass more items to the view.
Now is:
for (Message msg : messages) {
titles.add(msg.getTitle());
ArrayAdapter adapter = new ArrayAdapter(this, R.layout.row, titles);
And I would like pass to the view the title and date, and in row.xml, show two diferent TextView with its design.
Thanks, sorry my English, I am Spanish.
March 12, 2010 at 07:07
Hi All !
i got some problem with running my android application on actual device : (Motorola milestone droid 2.0.1) . Althoug it’s working fine on Virtual Android (I’m using Eclipse, buiding an android application about loadFeed, work with XML from internet, using ANDROID_SAX). I dont know why ? Anybody help me, thank you very much
I got sample code from this webpage :
http://www.warriorpoint.com/blog/2009/07/19/android-reading-using-and-working-with-xml-data-and-web-services-in-android/
April 11, 2010 at 03:37
Hi… I tried using this tutorial to transfer a simple object of mine but unable to do so. I am sure what is going wrong and where..could some one please look at my code placed in
http://www.sis.pitt.edu/~arazeez/xml.
Any help would be greatly appreciated.
Thanks,
Raqeeb
April 11, 2010 at 03:43
sorry.. i am unable to place my code on the server. please just send a mail to abdulraqeeb33@gmail.com, i can send across the code to you. thanks…
May 4, 2010 at 11:21
I am having difficulty adapting this method to my own xml output. I have successfully went through all of the code and changed the string names and it continues to work on the xml feed provided but when I change the url and the values that it is looking for it stops working. I can use any help you can give as I am still verymuch a novice at this. My xml is as follows:
25889
Forex UK Real
Manually trading with custom indicators and $250 starting balance. Strategy is to use ADX crosses on various time frames for entry points and then allowing a custom EA to close out the trades with a profit and limit the risk of a trend change.
10322997
-16.96
-8.48
-0.68
-19.9
252.50
500.00
0.10
-42.41
205.09
21.99
205.09
false
05/04/2010 08:39
04/11/2010 11:09
0
6
Forex.com
28288
Basel Financial Demo
Mini Demo account for manual trading.
505183
58.20
58.20
5.29
150.88
0.00
250.00
0.00
145.50
395.50
4.98
395.50
true
04/30/2010 09:34
04/26/2010 02:35
1
16
Basel Financial
28569
FXDD Contest Account
This demo account is for the contest.
7602194
60.47
60.46
12.09
325.58
0.00
1000.00
-1.36
604.64
1604.64
13.84
1604.64
true
05/02/2010 19:54
04/27/2010 08:26
0
5
FXDD
May 4, 2010 at 11:21
EDIT: tags did not show up
25889
Forex UK Real
Manually trading with custom indicators and $250 starting balance. Strategy is to use ADX crosses on various time frames for entry points and then allowing a custom EA to close out the trades with a profit and limit the risk of a trend change.
10322997
-16.96
-8.48
-0.68
-19.9
252.50
500.00
0.10
-42.41
205.09
21.99
205.09
false
05/04/2010 08:39
04/11/2010 11:09
0
6
Forex.com
28288
Basel Financial Demo
Mini Demo account for manual trading.
505183
58.20
58.20
5.29
150.88
0.00
250.00
0.00
145.50
395.50
4.98
395.50
true
04/30/2010 09:34
04/26/2010 02:35
1
16
Basel Financial
28569
FXDD Contest Account
This demo account is for the contest.
7602194
60.47
60.46
12.09
325.58
0.00
1000.00
-1.36
604.64
1604.64
13.84
1604.64
true
05/02/2010 19:54
04/27/2010 08:26
0
5
FXDD
June 6, 2010 at 13:23
Hi
The link for code download at IBM has been locked down. Could you give someone a poke over there? (if that’s possible..). If not would it be possible for you to mail me the code? I’d love to look at it within eclipse!
August 13, 2010 at 10:00
My name is Sang Shin. I am the founder and chief instructor of JavaPassion.com.
I am wondering if I can use this code as part of my Android programming course. Your name will be mentioned as part of the course material.
Thanks.
-Sang
August 19, 2010 at 06:27
Is the parsing process really that slow? I discovered times between 0,6 and 3,5 seconds depending on the parsing engine. But sounds still very slow to me. Do u guys have same delays?
September 30, 2010 at 03:25
I want to push XML data from Android to a web service
November 7, 2010 at 20:24
I can’t live without android at this point.
January 10, 2011 at 02:49
how to parse the XML node with namespaces?
March 2, 2011 at 08:08
Hi, really very nice tutorial.
My question is-how to get images from the rss feed xml file and display it in our android application of rss reader.
please rply in rohitmud@gmail.com
Thanks in advance
May 9, 2011 at 08:11
Hi,i am getting response from a web service in XSLT format.
Please help me to parse data in a Listview.
like full result list view
TotalApplicants=152
session_name=test1
start_date=2011-04-11T00:00:00+01:00
code——————–
package com.webservice;
import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapPrimitive;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.AndroidHttpTransport;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class WebService extends Activity
{
/* private static final String SOAP_ACTION = “http://tempuri.org/Ilogin/Logincheck”;
private static final String METHOD_NAME = “Logincheck”;
private static final String NAMESPACE = “http://tempuri.org/”;
private static final String URL = “http://122.248.245.146:8090/login.svc?wsdl”;*/
private static final String SOAP_ACTION =”http://tempuri.org/Isessions/open”;
private static final String METHOD_NAME = “open”;
private static final String NAMESPACE = “http://tempuri.org/”;
private static final String URL =”http://122.248.245.146:8090/sessions.svc?wsdl”;
/*private static final String SOAP_ACTION =”http://tempuri.org/Isessions/close”;
private static final String METHOD_NAME = “close”;
private static final String NAMESPACE = “http://tempuri.org/”;
private static final String URL =”http://122.248.245.146:8090/sessions.svc?wsdl”;*/
TextView tv;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv =(TextView)findViewById(R.id.textView1);
SoapObject Request = new SoapObject(NAMESPACE, METHOD_NAME);
//SoapObject
Request.addProperty(”name”, “priyanka”);
Request.addProperty(”passcode”, “employer2″);
//Request.addProperty(”logging”,”YES”);
Request.addProperty(”status”, 1);
//Request.addProperty(”status”, 0);
SoapSerializationEnvelope soapEnvelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
soapEnvelope.dotNet=true;
soapEnvelope.setOutputSoapObject(Request);
tv.setText(”Status0 :”);
AndroidHttpTransport abt = new AndroidHttpTransport(URL);
try
{
abt.call(SOAP_ACTION, soapEnvelope);
//SoapPrimitive resultString = (SoapPrimitive)soapEnvelope.getResponse();
// SoapObject resultString = ((SoapObject)soapEnvelope.getResponse());
// System.err.println(resultString.getName());
tv.setText(”Status1 :” + soapEnvelope.getResponse());
}
catch (Exception E)
{
E.printStackTrace ();
}
}
}
July 30, 2011 at 18:14
9JJ0wr http://ueNx8wqkk3Mnd.com
August 30, 2011 at 03:14
what is the use of default handler in this above example application?
September 30, 2011 at 08:09
Awesome post, wish I could come up with stuff like that for my forum, hahaha.
October 31, 2011 at 03:24
Hai i done webservices in net.I want to pass those webservices in android by using json but i m not getting values in android.Please help me
November 9, 2011 at 05:13
This is awesome!! thanks for sharing with us. you may check out this following url for brief knowledge on how to create android application using XML…
http://mindstick.com/Articles/b14ad2c6-2521-41c5-bb17-f98a872ee127/?Creating%20an%20Android%20Application%20by%20using%20XML%20Layout
Thanks !!!
November 11, 2011 at 07:41
i am new to android please help me how can i feed news from mashable.com after importing androidxml simple file i am gettimg error my emailid is durgeshpathakk@gmail.com
December 2, 2011 at 18:57
Thank you very much. If you do not mind, will translate the article into my native language
December 6, 2011 at 07:49
The manager Nymphet Preteen
=-)
December 21, 2011 at 23:33
Hi, Thanks for your tutorial. I have a question want to ask you. How can I get url link from enclosure tag?
Best Regards
December 29, 2011 at 23:47
How to parse the XML node with namespaces?
January 2, 2012 at 11:52
Hello, thanks for your post! Its realy helpful!