ART
ART is a lightweight, multiplatform web based query tool and reporting environment. Easy customizable, support graphs, export resultset in various formats via plug-ins.

Cewolf
Cewolf can be used inside a Servlet/JSP based web application to embed complex graphical charts of all kinds (e.g. line, pie, bar chart, plots, etc.) into a web page. Therefore it provides a full featured tag library to define all properties of the chart (colors, strokes, legend, etc.). Thus the JSP which embedds the chart is not polluted with any java code. Everything is described with XML conform tags.

Chart2D
Chart2D is a library written in Java for adding 2D charts to Java programs.

Datavision
DataVision is an Open Source reporting tool similar to Crystal Reports. Reports can be designed using a drag-and-drop GUI. They may be run, viewed, and printed from the application or exported as HTML, XML, PDF, LaTeX2e, DocBook, or tab- or comma-delimited text files. The output files produced by LaTeX2e and DocBook can in turn be used to produce PDF, text, HTML, PostScript, and more.

iReport
iReport is a visual reporting tool based on JasperReports written in 100% pure java. You can manage charts, images, subreports,... Data can be retrived using JDBC, TableModels, JavaBeans, XML,...It supports output in PDF,XML,XLS,CSV,HTML,Java2D,...

JasperReports
JasperReports is a powerful open source Java reporting tool that has the ability to deliver rich content onto the screen, to the printer or into PDF, HTML, XLS, CSV and XML files.

JCCKit
The Java Chart Constuction Kit (JCCKit) is a small (< 100Kb) Java library and a very flexible framework for creating scientific charts and plots.

JChart2d
A Java swing widget (JComponent) for precise runtime-dynamic display of tupels in form of a stripe chart. Intended for engineering task where precision is more important than a huge variety of different beautiful presentations. Key features are a minimal configuration effort, automatic scaling and labeling, thread-safeness, a clean and extendible API and extensive documentation.

jCharts
jCharts is a 100% Java based charting utility that outputs a variety of charts. This package has been designed from the ground up by volunteers for displaying charts via Servlets, JSP's, and Swing apps.

JFreeChart
JFreeChart is a free Java class library for generating charts.