java验证码工具类
package cn.rx.oamp.util;import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public final class ImageCode { private static final Random random = new Random(); private static final Font[] CODEFONT = { new Font("宋体", Font.BOLD, 25), new Font("宋体", Font.BOLD, 25), new Font("宋体", Font.BOLD, 25), new Font("宋体", Font.BOLD, 25) }; private static final Color[] FONTCOLOR = { Color.ORANGE, Color.RED, Color.PINK, Color.BLUE, Color.GREEN }; private static final Color[] BGCOLOR = { Color.WHITE, Color.GREEN }; private static final Color LINECOLOR = new Color(242, 234, 15); private static final String[] CODE = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" }; private static StringBuffer CONDENUMBER = null; private static final int WIDTH = 100, HEIGHT = 25; public final String image(HttpServletRequest request, HttpServletResponse response) { CONDENUMBER = new StringBuffer(); BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB); Graphics g = image.getGraphics(); g.setColor(BGCOLOR[random.nextInt(1)]); g.fillRect(0, 0, WIDTH, HEIGHT); for (int i = 0; i < 4; i++) { drawCode(g, i); } drawNoise(g, 8); g.setColor(Color.gray); g.drawRect(0, 0, WIDTH - 1, HEIGHT - 1); g.dispose(); response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); response.setContentType("image/png"); ServletOutputStream sos = null; try { sos = response.getOutputStream(); ImageIO.write(image, "png", sos); sos.flush(); sos.close(); } catch (Exception e) { e.printStackTrace(); return null; } return CONDENUMBER.toString(); } private final void drawCode(Graphics graphics, int i) { String number = CODE[random.nextInt(36)]; graphics.setFont(CODEFONT[random.nextInt(4)]); graphics.setColor(FONTCOLOR[random.nextInt(5)]); graphics.drawString(number, 10 + i * 20, 20); CONDENUMBER.append(number); } private final void drawNoise(Graphics graphics, int lineNumber) { graphics.setColor(LINECOLOR); int pointX1, pointY1, pointX2, pointY2; for (int i = 0; i < lineNumber; i++) { pointX1 = 1 + (int) (Math.random() * WIDTH); pointY1 = 1 + (int) (Math.random() * HEIGHT); pointX2 = 1 + (int) (Math.random() * WIDTH); pointY2 = 1 + (int) (Math.random() * HEIGHT); graphics.drawLine(pointX1, pointY1, pointX2, pointY2); } } } ?