PLOTICUS is a command line utility for creating bar, line, pie, boxplot, scatterplot, sweep, heatmap, vector, timeline, Venn diagrams, and other types of charts and plots. ploticus is good for automated or just-in-time graph generation. It handles date, time, and categorical data nicely, and has some basic statistical capabilities. It can output to GIF, PNG, SVG, SWF, JPEG, PostScript, EPS, and X11. You can use convenient preset options or create complex scripts with rich and detailed color and style operations.
ProteomeCommons.org IO Framework is a proper Java framework for handling spectra and peak lists. The framework can read and write to a number of different spectra and peak list formats, and it provides a simple, intuitive Java object model for working with spectra or peak lists. All classes support two methods of handling peak list and spectrum data: in-memory or stream. The goal of this framework is to support all the popular MS and MSMS data formats, and to eliminate any time or effort involved in figuring out how to read and write peak list or spectrum files.