.jsp和servlet验证码 package Cls; import java.awt.Color

文件名称: .jsp和servlet验证码

所属分类: Java

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文件大小: 3kb

下载次数: 0

上传时间: 2012-01-06

提供者: small_*******

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详细说明： package Cls; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.Random; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder; public class MyVerifyCode extends HttpServlet { private sta tic MyVerifyCode instance; private final String ATTRIBUTE_NAME = "verifycode"; // ��֤��ַ�� private final int CODE_LENGTH =4; // ��֤��߶�� private static final int Height =30; // ��֤��Ƿ��Ҫ��תЧ�� private boolean ROTATE_FLAG = true; //��Ƿ��Ҫ�� private boolean FONT_FLAG=false; //��Ĭ�� private String font=""; //��Ĵ�С,Ĭ��Ϊ15 private int fontsize=15; private final String RAND_RANGE = "abcdefhgkmnpqrstuvwxyz" + "ABCDEFGHGKLMNPQRSTUVWXYZ" + "2345678"; // private Random rand=new Random(); public static Random rand = new Random(); private final char[] CHARS = RAND_RANGE.toCharArray(); // ��캯�� public MyVerifyCode() { } public static MyVerifyCode getInstance() { if (instance == null) instance = new MyVerifyCode(); return instance; } // ��ַ� private String getRandString() { StringBuffer vcode = new StringBuffer(); for (int i = 0; i < CODE_LENGTH; i++) vcode.append(CHARS[rand.nextInt(CHARS.length)]); return vcode.toString(); } // �� public static float getRandomJiao() { float jiao = 0.0f; if (rand.nextFloat()<=0.5) { jiao = rand.nextFloat()-0.3f; } else { jiao = -rand.nextFloat()+0.3f; } return jiao; } // ��ɫ private Color getRandColor(int ll, int ul) { if (ll > 255) ll = 255; if (ll < 1) ll = 1; if (ul > 255) ul = 255; if (ul < 1) ul = 1; if (ul == ll) ul = ll + 1; int r = rand.nextInt(ul - ll) + ll; int g = rand.nextInt(ul - ll) + ll; int b = rand.nextInt(ul - ll) + ll; Color color = new Color(r, g, b); return color; } private BufferedImage getImage(HttpServletRequest request) { //根据设置的高度计算事宜的fontsize int FontSize=Height*75/96; //根据设置的字体及字的个数计算出适宜的宽度 int width = CODE_LENGTH * FontSize*4/5 + 10; //根据字体大小设置X轴的位移量 int X_=FontSize/2; BufferedImage image = new BufferedImage(width,Height, BufferedImage.TYPE_INT_RGB); // ��ȡͼ�� Graphics graphics = image.getGraphics(); Graphics2D g2 = (Graphics2D) graphics; g2.setColor(getRandColor(100, 255)); g2.setColor(Color.WHITE); g2.fillRect(0, 0, width, Height); g2.translate(0, Height*2/3); double oldrot = 0; String vcode=this.getRandString(); // 把验证码存入session request.getSession(true).setAttribute("codes", vcode); for (int i = 0; i < CODE_LENGTH; i++) { g2.setFont(new Font("Times New Roman", Font.HANGING_BASELINE, FontSize)); double rot = getRandomJiao(); // 旋转画笔 if (ROTATE_FLAG) { g2.rotate(-oldrot); g2.translate(X_+rand.nextInt(8), 0); oldrot = rot; g2.rotate(rot); } String temp = vcode.substring(i, i + 1); g2.setColor(getRandColor(1, 100)); g2.drawString(temp, 0, 0); } // ͼ��Ч g2.dispose(); return image; } public void printImage(HttpServletRequest request, HttpServletResponse response) { // ��ContentType��Ϊ"image/jpeg"��ʶ��ͼ��ʽ�� response.setContentType("image/jpeg"); // ��ҳ�治�� response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 2000); // ��֤�� String verifyCode = this.getRandString(); // ��֤��ͼ�� BufferedImage bi = this.getImage(request); try { // ��Servlet�� ServletOutputStream outStream = response.getOutputStream(); // ��ͼ��ݱ��ΪJPEG��ı�� JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(outStream); // ��ͼ��ݽ��б�� encoder.encode(bi); // ǿ�н��뵽ҳ�� outStream.flush(); // �ر�� outStream.close(); } catch (IOException ex) { ex.printStackTrace(); } } public void doGet(HttpServletRequest request, HttpServletResponse response) { printImage(request, response); } } ...展开收缩

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