SOLoist Explorer

SOLoist Explorer™ is a simple tool that provides an HTTP interface for:

  • writing and executing OQL queries (results in HTML or Excel sheet; see generated SQL, etc.)
  • browsing the UML model
  • browsing the object space

It is implemented as a servlet in the SOLoist library.

Basic Installation

The servlet should be added to web.xml of your web application:


The servlet will be accessible at the given URL, e.g. http://localhost:8080/MyWebApplication/oql.

Advanced Installation


OQLServlet provides no authentication mechanism whatsoever. You should use application specific filters (e.g. LoginFilter from EmptyProject).


OQLServlet supports the following init parameters:

  • title - Text to be used as the page title (default: SOLoist Explorer).
  • stylesheet - URL of the external CSS stylesheet to be used instead of the default style.
  • method - HTTP method used for HTML form submission. Values: GET (default) or POST.




Problem with UTF-8 encoding when using GET method

There might be a problem if some servlet containers (e.g. Tomcat) do not use UTF-8 to parse request parameters from the query string of the request URI. There are two soloutions to this problem:

  1. solution(partial): Make OQLServlet use POST method instead.
  2. solution (Tomcat only): Make Tomcat use UTF-8 encoding for request parameters encoded in query string. Edit server.xml and add useBodyEncodingForURI=“true” to Connector, for example:
    <Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443" useBodyEncodingForURI="true"/>

    Alternatively, you might use URIEncoding=“UTF-8”.

More info about configuring Apache Tomcat can be found on Apache Tomcat website.