Publication of Web Services

With Virtual DataPort you can publish views as a Web service to enable external applications that cannot use the JDBC or ODBC interfaces, to retrieve data from Virtual DataPort.

You can deploy these Web services to the Web Service container embedded in the Denodo Platform, or generate a war file to deploy it in an external J2EE applications server.

In Virtual DataPort there are two types of Web services:

  • SOAP Web service: set of operations that when invoked, the Service executes a specific a VQL query over a view.
  • REST Web service: set of views and associations. In a REST Web service, you do not define operations over these views. Instead, the Service follows the same RESTful approach as the Denodo RESTful Web service (see section RESTful Web Service of the Administration Guide). These Web services provide four different representations of the data.
    • HTML
    • XML
    • JSON
    • RSS

The main difference between the two types is that the SOAP Web services are “operation-oriented” and the REST Web services are “resource-oriented”.

Both types provide different authentication methods to validate users’ identity (see section Connection Parameters).

This section describes how to create and deploy SOAP and REST Web services using VQL statements.

In the previous versions of the Denodo Platform, there was only one type of Web service, which combined the SOAP and REST types. In the current version of the Platform, the Web services have been divided into two: the SOAP ones and the REST ones because the REST Web services have changed from an “operation-oriented” approach to a “RESTful” approach.

The Web services created with the previous versions of the Platform still work, but they are deprecated. We have moved the sections regarding the managing the old Web services to the appendix Web Services Created with Previous Versions of the Denodo Platform.

Note

We strongly recommend you to define new Web services using the Virtual DataPort Administration Tool (see the section Publication of Web services of the Administration Guide), because the syntax of the CREATE REST WEBSERVICE and CREATE SOAP WEBSERVICE statements is very complex.