RESTDoc: Describe, Discover and Compose RESTful Semantic Web Services using Annotated Documentations

ABSTRACT Development of a semantic web is gaining a lot of traction recently. At the same tim

Enabling Automatic Discovery and Querying of Web APIs at Web Scale using Linked Data Standards

International audienceTo help in making sense of the ever-increasing number of data sources available on the Web, in this article we tackle the problem of enabling automatic discovery and querying of data sources at Web scale. To pursue this goal, we suggest to (1) provision rich descriptions of data sources and query services thereof, (2) leverage the power of Web search engines to discover data sources, and (3) rely on simple, well-adopted standards that come with extensive tooling. We apply these principles to the concrete case of SPARQL micro-services that aim at querying Web APIs using SPARQL. The proposed solution leverages SPARQL Service Description, SHACL, DCAT, VoID, Schema.org and Hydra to express a rich functional description that allows a software agent to decide whether a micro-service can help in carrying out a certain task. This description can be dynamically transformed into a Web page embedding rich markup data. This Web page is both a human-friendly documentation and a machine-readable description that makes it possible for humans and machines alike to discover and invoke SPARQL micro-services at Web scale, as if they were just another data source. We report on a prototype implementation that is available on-line for test purposes, and that can be effectively discovered using Google's Dataset Search engine

Assessing Web Services Interfaces with Lightweight Semantic Basis

In the last years, Web Services have become the technological choice to materialize the Service-Oriented Computing paradigm. However, a broad use of Web Services requires efficient approaches to allow service consumption from within applications. Currently, developers are compelled to search for suitable services mainly by manually exploring Web catalogs, which usually show poorly relevant information, than to provide the adequate "glue-code" for their assembly. This implies a large effort into discovering, selecting and adapting services. To overcome these challenges, this paper presents a novel Web Service Selection Method. We have defined an Interface Compatibility procedure to assess structural-semantic aspects from functional specifications - in the form of WSDL documents - of candidate Web Services. Two different semantic basis have been used to define and implement the approach: WordNet, a widely known lexical dictionary of the English language; and DISCO, a database which indexes co-occurrences of terms in very large text collections. We performed a set of experiments to evaluate the approach regarding the underlying semantic basis and against third-party approaches with a data-set of real-life Web Services. Promising results have been obtained in terms of well-known metrics of the Information Retrieval field

Vergleich von Sprachen, Methoden und Tools zur Modellierung und Beschreibung von REST-Schnittstellen

Immer mehr APIs werden aufbauend auf der REpresentational State Transfer (REST)-Architektur implementiert und veröffentlicht. Trotz der Leichtgewichtigkeit dieser Dienste wird das Konzept eines einheitlichen Beschreibungsmodells oft vermisst. In dieser Fachstudie werden daher verschiedene Konzepte, Spezifikationen und Frameworks, welche REST Services modellieren, untersucht und bewertet. Die ausgereifteren Spezifikationen und Frameworks werden dabei anhand eines Kriterienkatalogs bewertet und abschließend verglichen

A semantic description language for RESTful data services to combat semaphobia

RESTful Web services are an increasingly popular way for companies to expose their data on the Web. On the other hand, the Linked Open Data initiative is gaining traction re-cently. Since REST’s principles align well with those of Linked Data, there is an increasing interest in the relationship of the two. Nevertheless, in practice they still largely remain separated, creating islands of data instead of a global graph of data forming the envisioned Semantic Web. There are different reasons for this. One is the reluctance of most Web developers to use Semantic Web technologies, a phenomenon we denote as Semaphobia. Another reason is that the Semantic Web is consi-dered to be a disruptive technology which does not consider exist-ing infrastructure. This makes it difficult for enterprises to update their legacy systems. To solve these and other issues, we propose a novel approach to semantically describe RESTful Data Services which in consequence leads to a mechanism to transform the data provided by such services to semantic resources. This aims to contribute to the availability of more semantic datasets. By keeping the approach as familiar and simple as possible for Web developers, we hope to lower the entry barrier and to foster the adoption of our approach