Home ›

Extending Web Services Using Other Web Services

Issue 144

From Issue #144
April 2006

Feb 23, 2006  By Reuven M. Lerner
 in
How to create a useful new Web service by tapping in to the power of two other freely available Web services.

Listing 4. xmlrpc-lookup-client.rb 


#!/usr/bin/ruby

require 'xmlrpc/client'

# Get the ISBNs from the command line
isbns = ARGV

# Connect to the server
server = XMLRPC::Client.new2("http://127.0.0.1:8080/", nil, 120)

# Send the ISBNs, and catch any faults that we find
begin
  results = server.call("atf.books", isbns)
rescue XMLRPC::FaultException => e
  puts "Error:"
  puts e.faultCode
  puts e.faultString
end

# Display the results!
results.each do |result|
  result.each do |key, value|
    if key == "ISBN"
      puts "ISBN: #{value}\n"
    else
      puts "\t#{key}: #{value}\n"
    end
  end
end
Conclusion

Seasoned programmers rarely implement everything themselves. The days in which every application needed its own video and printer drivers, to say nothing of a filesystem or operating system, are long behind us. Instead, we now have hierarchies of software libraries, with each library making use of lower-level data and functions and also performing similar tasks for higher-level libraries.

Web services haven't changed the need for building new libraries on top of old ones. Indeed, we can expect to see an explosion of such new libraries in the future. The difference is that new libraries will often be based on Web services, which provide platform and language independence. We will see basic, middleware and high-level Web services, available from anywhere on the Internet and callable from any operating system or language. This month, we looked at one way in which we can create a new Web service out of an old one. Each call to our xmlrpc-lookup server fired off a query to Amazon's Web services. Information from Amazon was then combined with another data set, with results that are useful to anyone living in Skokie, Illinois. We can expect to see similar aggregating Web services in the future, both free of charge and for pay.

Resources for this article: /article/8828.

Reuven M. Lerner, a longtime Web/database consultant, is currently a PhD student in Learning Sciences at Northwestern University in Evanston, Illinois. He and his wife recently celebrated the birth of their son Amotz David.

______________________

Webcast
More Resources
How to Build an Optimal Hadoop Cluster to Store and Maintain Unlimited Amounts of Data Using Microservers

Realizing the promise of Apache® Hadoop® requires the effective deployment of compute, memory, storage and networking to achieve optimal results. With its flexibility and multitude of options, it is easy to over or under provision the server infrastructure, resulting in poor performance and high TCO. Join us for an in depth, technical discussion with industry experts from leading Hadoop and server companies who will provide insights into the key considerations for designing and deploying an optimal Hadoop cluster.

Learn More

Sponsored by AMD

White Paper
More Resources
Private PaaS for the Agile Enterprise

If you already use virtualized infrastructure, you are well on your way to leveraging the power of the cloud. Virtualization offers the promise of limitless resources, but how do you manage that scalability when your DevOps team doesn’t scale? In today’s hypercompetitive markets, fast results can make a difference between leading the pack vs. obsolescence. Organizations need more benefits from cloud computing than just raw resources. They need agility, flexibility, convenience, ROI, and control.

Stackato private Platform-as-a-Service technology from ActiveState extends your private cloud infrastructure by creating a private PaaS to provide on-demand availability, flexibility, control, and ultimately, faster time-to-market for your enterprise.

Learn More

Sponsored by ActiveState