Webservices interfaces: SOAP and RESTful
In this technical article, we compare the webservice interfaces SOAP and REST. webPDF provides its PDF functions as SOAP services and as RESTful webservices. But what are the differences between SOAP and RESTful, and what are their strengths and weaknesses?
In software development, terms like API and RESTful API are used constantly. Since APIs are a core part of modern systems, it is worth taking a closer look. API stands for Application Programming Interface.
Interfaces make communication between systems possible. Alongside website design and implementation, API design and documentation are now standard parts of development. Over time, several standards and protocols have become established. SOAP is one of the best-known examples.
Comparing webservice interfaces: SOAP and RESTful
| SOAP (Simple Object Access Protocol) | REST (Representational State Transfer) |
|---|---|
| Network protocol | Architectural style for web services |
| Typical use: SAP and enterprise environments | Typical use: web environments and public APIs |
| W3C standard, XML-based, often over HTTP/TCP | Resource-oriented design via URI |
| Often used in stateless request/response scenarios | Frequently used with lightweight, scalable HTTP patterns |
| Drawback: XML overhead and higher complexity | Drawback: less strict standardization |
| Benefit: strong standards and broad platform compatibility | Benefit: simpler implementation and good scalability |
Stateless vs. stateful in brief
- Stateless: Every request contains all required information; the server does not keep session context between requests.
- Stateful: The server can keep client context across multiple requests; this can help in workflow-heavy scenarios but may increase server load.
webPDF 6.0: SOAP or RESTful - technical details
In practice, the right choice depends on the use case. Because both approaches offer different benefits, webPDF supports both. Webservices fit many integration scenarios and can be used independently of platforms, programming languages, and protocols.
webPDF webservice interfaces
| SOAP | RESTful |
|---|---|
| webPDF 6.0 provides SOAP webservices based on Java standards such as JSR 224. Interface descriptions are provided via WSDL. | webPDF 6.0 provides RESTful interfaces based on standards such as JSR 311. Resources are addressed by URI and represented, for example, in JSON. |
| Multiple SOAP methods are available for PDF processing. | HTTP methods such as PUT, GET, POST, and DELETE are supported. |
webPDF webservices
webPDF exposes all PDF functions through SOAP or RESTful webservices. This is convenient because services are platform-independent and can be integrated into different programming languages. The webPDF server provides a total of six webservices in both styles.
Learn more about PDF webservices
Editing functions enabled by the webservices
- File conversion to PDF
- Digital signing
- Conversion to PDF/A and validation of existing PDF/A documents
- Further PDF processing (sharing, saving, image export, printing)
- URL conversion: load HTML content by URL and convert it to PDF
- OCR of image-based documents and conversion to searchable PDF
Note: Each webservice provides dedicated parameters. These parameters control behavior and execution and are consistent across SOAP and RESTful interfaces.