Web Services and SOAP (or REST) are quickly becoming condition-of-art architectural methods to permit the access of multiplatform and multilanguage systems,
A lot of companies have legacy applications which represent a higher investment and Web Services promise to permit their access on the internet without extensive modifications.
2. Introducing Web Services
Web services contain several standards meant to make it easy for diverse systems to speak, without requiring a specific kind of middleware, programming language or perhaps operating-system. They may be according to SOAP, REST or XML-RPC,.
SOAP is definitely an free message standard, according to an XML dictionary, that utilizes standard transport protocols broadly used on the internet for example HTML or SMTP. It represents a paradigm shift in the manner applications talk to one another, because it doesn’t require any special middleware to permit diverse applications to speak. The messages are text based and accessible by application within the network. They’re described using a special XML based language known as WSDL.
REST is really a simpler kind of Web Service in which the user simply accesses a Hyperlink to obtain back an XML document with no standard specs.
XML-RPC is a method to send instructions to a different system by utilizing and XML document.
Web service let it develop loosely coupled applications, by permitting systems according to different technologies and languages to speak by utilizing open standard largely according to XML.
3. Consuming Web Services from Cobol or RPG
If you want to access an internet Service from the Cobol or RPG program, you should use the IBM Web Services Client for C toolkit.
It uses extenal data structures to define the mappings between aspects of an XML document and fields functional in Cobol or RPG applications and enables to create C or C functions which may be known as through the Cobol or RPG program to invoke the net service. The generation is dependant on the WSDL file which describes the net service.
4, Exposing Legacy programs in Cobol or RPG as Web Services
If you wish to access legacy Cobol or RPG programs as Web Services, you should use the IBM Toolbox for Java or JTOpen to build up a Java Web Service which calls the Cobol or RPG program and return the outcomes like a SOAP message.
It enables to build up clients in Java or any other languages to legacy Cobol or RPG program and return the outcomes as XML messages based on the Web services specifications.
5. Using PHP with Web Services
PHP has lately been ported towards the IBM iSeries systems.
PHP includes a good support for Web Services and SOAP mainly in the PHP 5 version.
Spot the PHP services can call also call programs designed in other languages for example Cobol or RPG and for that reason PHP is definitely an option to the approach from the previous point.
6. DB2 Web Services
Data in relational database could be utilized though finish-user queries in SQL or any other interfaces or by applications which use programming interfaces for example JDBC and SQLJ.
DB2 enables and to use Web services to question the database and to get the results as standard SOAP messages.
There are plenty of helpful information and tutorials around the above tools and techniques in the URL