1. Techniques to Invoke Web Services from SAS
Leveraging Web Services within your SAS Programs

2. Greg Ludwinski, Statistics Canada
Agenda
Introduction to Web Services
SOAP
WSDL
Using Services
Techniques to Invoke Web Services
What SAS offers
Benefits and Limitations
An alternative Approach
Demonstration
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

3. Greg Ludwinski, Statistics Canada
What is a Web Service?
A software application identified by a URI
Defined, described and discovered as xml artifacts (WSDL).
Supports direct interactions with other software agents using XML-based messages (SOAP) exchanged via standard network protocols (HTTP).
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

4. Greg Ludwinski, Statistics Canada
Web Services Stack
UDDI
Discovery & publication
WSDL
Service description
Management
QOS
Security
SOAP
Messaging
HTTP, TCP
Transportation
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

5. Greg Ludwinski, Statistics Canada
SOAP
SOAP is an XML based markup language for messaging between applications.
Web Services expose functionality to users through SOAP.
Transport protocol neutral
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

6. SOAP Message Structure
SOAP Message (an XML document)
SOAP Envelope
WS-Security
WS-Addressing
SOAP Header (optional)
Header
Header
Request/ Response Data
SOAP Body (payload)
Error handling
XML content
SOAP Fault (optional)
Allows for different encoding
Attachment
(optional)
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

7. WSDL (Web Service Description Language)
A contract between the Web service and the client who uses it.
An XML document that describes the Web Service and defines the functions that are exposed.
It also defines where the service is available and what communication protocol is used to talk to the service.
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

8. WSDL Structure Service Port Port Binding Binding Port Type Operations
Where is it and how to use it.
Port
(e.g.
Port
(eg. ftp://...)
Binding
(e.g. SOAP)
Binding
(e.g. ebXML)
Interface for service operations
1 or more service operations
Port Type
Operations
Description of inputs and outputs using types and schemas
Input
message
Output message
Abstract Interface
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

9. First & last name Company name
RESTful Web Services
A lightweight alternative to SOAP based web services
Plain XML and JSON are popular message protocols
Standards are not as well defined
HTTP header is used for security
Thursday, May-30-19
First & last name Company name

10. Calling Web Services from SAS
RESTful Web Services
Proc Http
URL file reference
SOAP based Web Services
Proc SOAP
Functions SOAPWEB, SOAPWS,
The WSDL markup type dropped in 9.3
Custom Java Objects
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

11. Greg Ludwinski, Statistics Canada
Proc Http
proc http method=<post|get> in=<fileref for request parameters(post)> out=<fileref for response> url=“<Path to service endpoint>” ; run;
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

12. Greg Ludwinski, Statistics Canada
Proc SOAP
proc soap in=<fileref for request> out=<fileref for response> url=“<Path to service endpoint>” soapaction=“<Path to service operation>” ; run;
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

13. Preparing for Proc SOAP
Use a tool such as SOAPUI to create a service request template
Invoke the web service to get a sample response
Create an XMLMap to convert the response
Determine additional requirements (Security, Timeout Settings, Timestamp)
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

14. Using Custom Java Objects
Why use Java?
SAS uses Java (Proc SOAP)
Rich class libraries available (Web Service Frameworks, Security . .. )
How?
Develop a class and put it in a JAR file
Update your SAS Configuration file:
Add the JAR file to the Classpath
Set any required JREOptions
Java objects will be available in your SAS session
Thursday, May-30-19
Greg Ludwinski, Statistics Canada

15. First & last name Company name
Java objects in SAS
Created within a data step
SAS provides methods to;
Call static & non-static methods (9 types)
Get/Set static & non-static fields (9 types)
Detect & Clear exceptions
Flush output
Delete objects
Thursday, May-30-19
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16. First & last name Company name
Using Java Objects
Data _null_; /* Declared and instantiate */ declare javaobj myJavaObject; myJavaObject = _new_ javaobj("<classname>"); /* Call static/non static methods */ myJavaObject.callVoidMethod("<methodname>", <parm1>); myJavaObject.callStringMethod("<methodname>", <parm1>, <outstringVar>); /* Object clean up */ myJavaObject.delete(); run;
Thursday, May-30-19
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17. First & last name Company name
Demonstration
Thursday, May-30-19
First & last name Company name

18. Greg Ludwinski Statistics Canada
Comments / Questions
Statistics Statistique
Canada Canada
Greg Ludwinski
Project Leader - SAS Technology Centre
System Engineering Division
R.H. Coats Building, 14th Floor, Section Q
Ottawa, Ontario, Canada K1A 0T6
(613) Fax (613)
Canada
Thursday, May-30-19
Greg Ludwinski Statistics Canada