Background to the Bank of England URL

For your convenience, the URL for the currency rate conversion service that we’re using in this example is provided here. You can use this link to practise making the changes demonstrated in our example.

http://www.bankofengland.co.uk/mfsd/iadb/fromshowcolumns.asp?Travel=NIxIRxSUx&FromSeries=50&DAT=RNG&FD=1&FM=Jan&FY=1963&TD=23&TM=Jun&TY=2011&VFD=Y&CSVF=TT&C=C8J&Filter=N&xml.x=8&xml.y=11

For configuring REST connections, you need to understand a little about the structure of URLs. The structure is more straightforward than may seem at first sight.

Root

http://www.bankofengland.co.uk/mfsd/iadb/fromshowcolumns.asp?

Query string

Travel=NIxIRxSUx&FromSeries=50&DAT=RNG&FD=1&FM=Jan&FY=1963&TD=23&TM=Jun&TY=2011&VFD=Y&CSVF=TT&C=C8J&Filter=N&xml.x=8&xml.y=11

Notice the form of the URL. A typical web service URL contains two parts, separated by a question mark. The first part,shown in the first box, is called the root of the URL.

The “?” is not strictly part of the root. The part after the “?”, shown in the second box, is called the query string.

When an HTTP client makes a request, the server responds according to the URL it receives. The root calls the web service, identifying the server, the path and the file or program. The query string is passed to the program, where its parameters and values are used to generate output.

When configuring a REST service, you’ll notice in the demo that you initially specify only the root of the URL, omitting anything after the “?”. You make use of the query component later in the configuration.