Computer Science 101 Web Services

Alsos Search for Niels Bohr

AtomicArchive.Com Article on Niels Bohr

AtomicArchive.Com Article on Niels Bohr (cont.) Produces Alsos Search

Alsos Search for Niels Bohr

A specific reference

That’s what they get, not what they want! We are providing them with a mechanism, “dynamic links”, that enable them to do “live” searches into Alsos – not just link to the Alsos home page, but … We are providing them with a mechanism, “dynamic links”, that enable them to do “live” searches into Alsos – not just link to the Alsos home page, but … The user ends up in Alsos site, not Atomic Archives. The user ends up in Alsos site, not Atomic Archives. They would like a way to get data (annotations) from Alsos that they could format within their pages. They would like a way to get data (annotations) from Alsos that they could format within their pages.

What if we wanted to provide this: Suppose we wanted to provide a mechanism for developers to get data from us for use on their web pages. Suppose we wanted to provide a mechanism for developers to get data from us for use on their web pages. We would not want them to access our database with SQL statements We would not want them to access our database with SQL statements –Might change database –Want control of the kind of data we let them have Would not want to restrict to platform,.NET, Linux, etc. Would not want to restrict to platform,.NET, Linux, etc.

What if we wanted to provide this: (cont.) We would need a platform independent means of sharing data We would need a platform independent means of sharing data That’s exactly what XML is all about – it’s text based, marked up data. That’s exactly what XML is all about – it’s text based, marked up data. Web service – software component that you call over the web. Web service – software component that you call over the web. –Accepts and returns XML data

The Big Picture Just like HTML provides a standard way for marking up text for web page display, XML provides a standard way for marking up data. Just like HTML provides a standard way for marking up text for web page display, XML provides a standard way for marking up data. Web services then provide a standard way for programs to pass this data back and forth to each other. Web services then provide a standard way for programs to pass this data back and forth to each other.

Example – Google Service

Search Button private void btnSearch_Click (Object sender, System.EventArgs e) { GoogleSearchResult result = null; GoogleSearchService google; ResultElement re; google = new GoogleSearchService(); this.lstURLs.get_Items().Clear(); for (int i = 0; i < 20; i += 10) // get first 20 hits total { result = google.doGoogleSearch("4a8/TvZQFHID0WIWnL1CMmMx0sNqhG8H", this.txtSearch.get_Text(), i, 10, false, "", false, "", "", ""); for (int j = 0; j< result.resultElements.length; j++) { re = result.resultElements[j]; this.lstURLs.get_Items().Add(re.URL); } this.lstURLs.Refresh(); }//for-n-hits this.lblHits.set_Text( String.valueOf(result.estimatedTotalResultsCount) ); MessageBox.Show("Search complete, first 20 hits are shown!"); }

Item Selected private void lstURLs_SelectedIndexChanged (Object sender, System.EventArgs e) { java.lang.Object a, b, c, d; a = b = c = d = null; // optional parameters // navigate to selected site! this.axWebBrowser1.Navigate(this.lstURLs.get_Text(), a, b, c, d); }

Terra Service

Stock Ticker

Movie Theaters

Xmethods.net

Movie Service

Movie Service Description

Movie – Code for Find Button

Movie – Code for Theater Selection

Industry Scenario Suppose we have a huge industrial manufacturing company. Suppose we have a huge industrial manufacturing company. The parts we need are supplied by a number of different suppliers. The parts we need are supplied by a number of different suppliers. At a given time we may prefer one supplier over the others based on At a given time we may prefer one supplier over the others based on –Current price they offer –Adequacy of their inventory relative to our needs.

Industry Scenario (cont.) Assuming that all of these suppliers provide web services for our use, our decision and purchase could be automated: Assuming that all of these suppliers provide web services for our use, our decision and purchase could be automated: –Our inventory/purchasing program could communicate our needs to all of the supplier web services and receive their price and inventory information –Based on these results, our program could choose the lowest price among suppliers with acceptable inventories.