Distributed Systems COMP3211 – Coursework 2 Deadline: 10.00, Friday 15 November 2019 Introduction This exercise aims to give you some practical experience of writing server and clients to deploy and consume Web Services. Useful Resources • Web Services examples: available on COMP3211 area onMinerva • Documentation for Jersey http://jersey.java.net • Oracle Building Web Services with JAX-WS http://docs.oracle.com/javaee/6/ tutorial/doc/bnayl.html • Oracle Building Web Services with JAX-RS https://docs.oracle.com/javaee/6/ tutorial/doc/giepu.html • Servlets and JSP examples if you choose to develop the full, Web-based user interface to your application http://www.minerva.leeds.ac.uk The Task 1. Your main task is to build a Web Services client that integrates up to three Web services. The Web services are: • existing SOAP-based services; • existing RESTful services, e.g. Google, Amazon, Twitter, or other public directories; • your own SOAP-based service which you need to develop, e.g. using JAX-WS; • your own RESTful service which you need to develop, e.g. using Jersey or Flask- RESTful; • a combination of the above. Note: The composition involves a minimum of TWO Web services and a maximum of THREE. One of the Web services must be YOUR own and needs to be developed from scratch, i.e a proper server with a client to test it is functional. More marks will be allocated if you consider three Web services. Here are two imaginary examples: Example 1: Quote of the Day. The 1st service returns the name of an author which the integrated client should then use to do a search on the author using the 2nd service and output the top results/links for that author. Example 2: Shakespeare. The client would need to get the partial text of a speech from the user and pass it to the 1st service. It will then need to extract the name of the play or name of the speaker from the result and use these data to construct another search query to the 2nd Web service. Feel free to investigate the use of Web services provided on: • https://developers.google.com/ • https://aws.amazon.com/ • https://developer.twitter.com/ • http://www.programmableweb.com • http://mymemory.translated.net/doc/spec.php • https://flask-restful.readthedocs.io/ As you need to choose your own services, look at the services that you may find interesting, taking note of the implementation platform and examining the WSDL or REST API for each service. Note that the order of difficulty varies. Some services are easy to handle because results are returned as simple strings of plain text; others are slightly more challenging because the returned string is XML or JSON rather than plain text (albeit simple XML/JSON), therefore requires parsing. Some service providers e.g. Google, Twitter, Amazon) require users to be registered for authentication and authorisation purpose (an authentication key is usually provided after registration). There are various ways to develop your own services. The steps to follow to write server and client-side code are provided on Minerva. More marks are available if you tackle original and challenging services.
