JFreeChart and Cewolf—A Powerful Combination

Business applications typically manage data. Therefore, developers often need to provide components that enable users to analyze that data. One way to do this is by providing users access to text-based reports. Another option is to provide a view to the data through a series of graphical charts. Charts can be an extremely useful tool because they allow users to visually compare data elements, spotting trends and patterns not easily discernable through reports when dealing with large amounts of data.

Much of today's business software is Web-based and delivered through a browser. Nevertheless, requirements for these applications, namely data analysis requirements, remain the same.

Luckily, if you are developing software with J2EE technologies, there are some open-source options to assist you. This article will demonstrate how J2EE developers can quickly add visually-appealing, graphical charts to their work.

JFreeChart and Cewolf—A Powerful Combination
JFree.org is a Web site that hosts many useful open-source projects. JFreeChart is just one such project. It is managed by David Gilbert. JFreeChart consists of a number of Java libraries that generate graphical charts based upon a set of data.

Cewolf is another open-source project. Cewolf comes with its own set of libraries, as well as a collection of JSP tags. The Cewolf project, founded by Guido Laures, gives developers an easy way to display JFreeChart-built charts in a JSP page. In other words, Cewolf is a layer that rests upon JFreeChart. Cewolf provides data input to JFreeChart, then displays the resulting image in a browser, as dictated by the JSP tags. Both projects' libraries are necessary to achieve the desired goal. The most recent version of Cewolf, version 0.9.8, supports JFreeChart


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