Open Source Bridge 2010 June 2, 2010 Portland Oregon

1. Connecting to
Web Services on Android
Sean Sullivan
June 2, 2010

9. HTTP request
HTTP response

11. • HTTP
• XML
• JSON
• OAuth

12. + HTTP
Option 1
• java.net.URL
• java.net.HttpURLConnection
Option 2
• HttpClient 4.0 API

13. HttpClient 4.0 API
• org.apache.http.client.HttpClient
• org.apache.http.impl.client.DefaultHttpClient

14. HttpClient 4.0 API
• org.apache.http.client.methods.HttpGet
• org.apache.http.client.methods.HttpPost
• org.apache.http.client.methods.HttpPut
• org.apache.http.client.methods.HttpDelete

15. HttpClient 4.0 API
• org.apache.http.HttpResponse
• org.apache.http.StatusLine
• org.apache.http.HttpEntity
• org.apache.http.utils.EntityUtils

16. HttpClient programming
• HTTP response status code
• I/O exceptions
• timeouts
• gzip

17. HttpClient programming
synchronous invocation
public HttpResponse execute(HttpUriRequest request)
asynchronous invocation
public HttpResponse execute(HttpUriRequest request,
ResponseHandler handler)

18. UI programming
• user clicks on button
• onClick listener
• Don’t block the UI thread!
• Tip: use java.lang.Runnable

19. Response formats
• XML
• JSON
• RSS, Atom
• other

20. JSON processing
• json.org package
• Google GSON library
• XStream + Jettison
*
• json-lib
*
* does not work on Android 1.x

21. XML processing
• org.w3c.dom package (DOM)
• org.xml.sax package (SAX)
• org.xmlpull package (XPP)
• XStream
• JDOM
• Apache XmlBeans*
* does not work on Android 1.x

22. RSS and Atom
• Rome library *
• Apache Abdera library *
* does not work on Android 1.x

23. Client libraries
code.google.com/p/jfireeagle
code.google.com/p/jpoco
code.google.com/p/meetup-java-client

24. Client libraries
code.google.com/p/gdata-java-client
code.google.com/p/upcoming-java-client
flickrj.sourceforge.net

26. Conclusion
• HttpClient API
• use XStream for XML processing
• use Google GSON for JSON processing
• OAuth has a learning curve

27. Thank you