import java.awt.*; import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import Acme.JPM.Encoders.GifEncoder; import javachart.chart.*; // from Visual Engineering public class SimpleChart extends HttpServlet { static final int WIDTH = 450; static final int HEIGHT = 320; public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException ,IOException { ServletOutputStream out = res.getOutputStream(); Frame frame = null; Graphics g = null; try { // Create a simple chart BarChart chart = new BarChart("Apples and Oranges"); // Give it a title chart.getBackground().setTitleFont(new Font("Serif", Font.PLAIN, 24)); chart.getBackground().setTitleString("Comparing Apples and Oranges"); // Show, place, and customize its legend chart.setLegendVisible(true); chart.getLegend().setLlX(0.4); // normalized from lower left chart.getLegend().setLlY(0.75); // normalized from lower left chart.getLegend().setIconHeight(0.04); chart.getLegend().setIconWidth(0.04); chart.getLegend().setIconGap(0.02); chart.getLegend().setVerticalLayout(false); // Give it its data and labels double[] appleData = {950, 1005, 1210, 1165, 1255}; chart.addDataSet("Apples", appleData); double[] orangeData = {1435, 1650, 1555, 1440, 1595}; chart.addDataSet("Oranges", orangeData); String[] labels = {"1993", "1994", "1995", "1996", "1997"}; chart.getXAxis().addLabels(labels); // Color apples red and oranges orange chart.getDatasets()[0].getGc().setFillColor(Color.red); chart.getDatasets()[1].getGc().setFillColor(Color.orange); // Name the axes chart.getXAxis().setTitleString("Year"); chart.getYAxis().setTitleString("Tons Consumed"); // Size it appropriately chart.resize(WIDTH, HEIGHT); // Create an unshown frame frame = new Frame(); frame.addNotify(); // Get a graphics region of appropriate size, using the Frame Image image = frame.createImage(WIDTH, HEIGHT); g = image.getGraphics(); // Ask the chart to draw itself to the off screen graphics context chart.drawGraph(g); // Encode and return what it painted res.setContentType("image/gif"); GifEncoder encoder = new GifEncoder(image, out); encoder.encode(); } finally { // Clean up resources if (g != null) g.dispose(); if (frame != null) frame.removeNotify(); } } }