Demonstrate to Draw Bar Charts in Java
import java.awt.*; import java.awt.font.*; import java.awt.geom.*; import javax.swing.*; public class BarChart extends JApplet { public void init() { EventQueue.invokeLater(new Runnable() { public void run() { String v = getParameter("values"); if (v == null) return; int n = Integer.parseInt(v); double[] values = new double[n]; String[] names = new String[n]; for (int i = 0; i < n; i++) { values[i] = Double.parseDouble(getParameter("value." + (i + 1))); names[i] = getParameter("name." + (i + 1)); } add(new Component(values, names, getParameter("title"))); } }); } } class Component extends JComponent { public Component(double[] v, String[] n, String t) { values = v; names = n; title = t; } public void paintComponent(Graphics g) { Graphics2D g2 = (Graphics2D) g; if (values == null) return; double minValue = 0; double maxValue = 0; for (double v : values) { if (minValue > v) minValue = v; if (maxValue < v) maxValue = v; } if (maxValue == minValue) return; int panelWidth = getWidth(); int panelHeight = getHeight(); Font titleFont = new Font("SansSerif", Font.BOLD, 20); Font labelFont = new Font("SansSerif", Font.PLAIN, 10); FontRenderContext context = g2.getFontRenderContext(); Rectangle2D titleBounds = titleFont.getStringBounds(title, context); double titleWidth = titleBounds.getWidth(); double top = titleBounds.getHeight(); double y = -titleBounds.getY(); double x = (panelWidth - titleWidth) / 2; g2.setFont(titleFont); g2.drawString(title, (float) x, (float) y); LineMetrics labelMetrics = labelFont.getLineMetrics("", context); double bottom = labelMetrics.getHeight(); y = panelHeight - labelMetrics.getDescent(); g2.setFont(labelFont); double scale = (panelHeight - top - bottom) / (maxValue - minValue); int barWidth = panelWidth / values.length; for (int i = 0; i < values.length; i++) { double x1 = i * barWidth + 1; double y1 = top; double height = values[i] * scale; if (values[i] >= 0) y1 += (maxValue - values[i]) * scale; else { y1 += maxValue * scale; height = -height; } Rectangle2D rect = new Rectangle2D.Double(x1, y1, barWidth - 2, height); g2.setPaint(Color.BLUE); g2.fill(rect); g2.setPaint(Color.BLACK); g2.draw(rect); Rectangle2D labelBounds = labelFont.getStringBounds(names[i], context); double labelWidth = labelBounds.getWidth(); x = x1 + (barWidth - labelWidth) / 2; g2.drawString(names[i], (float) x, (float) y); } } private double[] values; private String[] names; private String title; }
<applet code="BarChart.class" width=640 height=520> <param name="title" value="Annual Turnover (Crores) of a Company during 2012 to 2020"/> <param name="values" value="9"/> <param name="name.1" value="2012"/> <param name="name.2" value="2013"/> <param name="name.3" value="2014"/> <param name="name.4" value="2015"/> <param name="name.5" value="2016"/> <param name="name.6" value="2017"/> <param name="name.7" value="2018"/> <param name="name.8" value="2019"/> <param name="name.9" value="2020"/> <param name="value.1" value="4000"/> <param name="value.2" value="5500"/> <param name="value.3" value="8000"/> <param name="value.4" value="25000"/> <param name="value.5" value="40000"/> <param name="value.6" value="50000"/> <param name="value.7" value="35000"/> <param name="value.8" value="20500"/> <param name="value.9" value="1500"/> </applet>
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