XML Interface for Network Services
XINS (XML Interface for Network Services) is an open source technology for definition and implementation of internet applications, which enforces a specification-oriented approach:
- first specifications need to written;
- then documentation and code is generated from these specifications;
- then the testing and implementation can start.
From specifications, XINS is able to generate:
- HTML documentation
- test forms
- SOAP-compliant WSDL
- a basic Java web application
- unit test code (in Java)
- stubs (in Java)
- client-side code (in Java)
Technically, XINS is composed of the following:
- An XML-based specification format for projects, APIs, functions, types and error codes
- A POX-style RPC protocol (called the XINS Standard Calling Convention), compatible with web browsers (HTTP parameters in, XML out).
- A tool for generating human-readable documentation, from the specifications.
- A tool for generating WSDL, from the specifications.
- A Log4J-based technology for logging (called Logdoc), offering a specification format, internationalization of log messages, generation of HTML documentation and generation of code.
- A Java library for calling XINS functions: the XINS/Java Client Framework; in xins-client.jar.
- A server-side container for Java-based XINS API implementations: XINS/Java Server Framework; in xins-server.jar. This is like a servlet container for XINS APIs. Since version 1.3.0, it supports not only POX-style calls, but also SOAP and XML-RPC. And it supports conversion using XSLT.
- A Java library with some common functionality, used by both the XINS/Java Client Framework and the XINS/Java Server Framework: the XINS/Java Common Library, in xins-common.jar.
An introductory tutorial called the XINS Primer takes the reader by the hand with easy-to-follow steps to perform, with screenshots.
XINS is open-source and is distributed under the liberal BSD license.
Specifications
All XINS specification files are plain old XML. Compared to SOAP/WSDL/UDDI the format is extremely simple. There are specifications for projects, environment lists, APIs, functions, types and error codes.
Below is an example of a XINS project definition.
<?xml version="1.0"?> <!DOCTYPE project PUBLIC "-//XINS//DTD XINS Project 1.3//EN" "http://www.xins.org/dtd/xins-project_1_3.dtd"> <project name="MyProject" domain="com.mycompany"> <api name="MyAPI"> <impl/> <environments/> </api> </project>
Here is an example of a specification of an environment list:
<?xml version="1.0"?> <!DOCTYPE environments PUBLIC "-//XINS//DTD Environments 1.3//EN" "http://www.xins.org/dtd/environments_1_3.dtd"> <environments> <environment id="netarray" url="http://xins.users.mcs2.netarray.com/myproject/xins/"/> </environments>
An example of an API specification file:
<?xml version="1.0"?> <!DOCTYPE api PUBLIC "-//XINS//DTD XINS API 1.3//EN" "http://www.xins.org/dtd/api_1_3.dtd"> <api name="MyAPI"> <description>My first XINS API</description> <function name="Hello"/> </api>
Competition
There are no known products that that provide an integrated approach to specification-oriented development, similar to XINS. However, there are several frameworks and libraries that provide functionality similar to individual parts of XINS, including:
- JWSDP: Collection of various XML and SOAP technologies for the Java programming language
- Apache Axis: Java-based framework for SOAP implementations.
- Hessian Web Service Protocol: Binary alternative to the XINS standard calling convention.