JHeatChart is a Java library for generating heat map charts.
Very few charting APIs seem to contain the facility to create heat maps (heat charts). So this is just a very small library for creating heat maps. It is not a full featured charting API, and you cannot use it to create line charts, bar charts or pie charts. But it is pretty good at its one job – heat charts.
The charts generated are created as Java Image objects which can be incorporated into a GUI or saved to a jpg, png or gif file on disk.