Perl Development & Consultancy

Graph drawing servlets

For several projects servlets written in the Java programming language were created to draw graphs. The excellent 2D graphics capablities of Java in combination with the open source servlet engine from the Jakarta/Tomcat project were used. The rendering takes place on a headless server running using Xvfb to provide a graphic context to Java2D.

One project consisted of creating a Java servlet able to draw many different kinds of bar charts, like stacked bar charts, percentage bar charts, comparison bar charts, etc. The object oriented nature of Java made it possible to write a generic application interface.

For an other project, visualisation of energy patterns, consisted of several line and bar graph drawing Java classes. Scaling of each graph is possible by passing dimension parameters to the servlet via its URL. Anti-aliasing is used to enhance the quality of the rendered bitmap.