JAVA小工具三：验证码

来源：互联网发布：剑雨江湖坐骑升级数据编辑：程序博客网时间：2024/05/01 01:49

创建验证图片：

package cn.itcast.vcode.utils;import java.awt.BasicStroke;import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.imageio.ImageIO;public class VerifyCode {private int w = 70;private int h = 35; private Random r = new Random(); // {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"}private String[] fontNames  = {"宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312"};private String codes  = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHIJKLMNPQRSTUVWXYZ";private Color bgColor  = new Color(255, 255, 255);private String text ;private Color randomColor () {int red = r.nextInt(150);int green = r.nextInt(150);int blue = r.nextInt(150);return new Color(red, green, blue);}private Font randomFont () {int index = r.nextInt(fontNames.length);String fontName = fontNames[index];int style = r.nextInt(4);int size = r.nextInt(5) + 24; return new Font(fontName, style, size);}private void drawLine (BufferedImage image) {int num  = 3;Graphics2D g2 = (Graphics2D)image.getGraphics();for(int i = 0; i < num; i++) {int x1 = r.nextInt(w);int y1 = r.nextInt(h);int x2 = r.nextInt(w);int y2 = r.nextInt(h); g2.setStroke(new BasicStroke(1.5F)); g2.setColor(Color.BLUE); g2.drawLine(x1, y1, x2, y2);}}private char randomChar () {int index = r.nextInt(codes.length());return codes.charAt(index);}private BufferedImage createImage () {BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); Graphics2D g2 = (Graphics2D)image.getGraphics(); g2.setColor(this.bgColor);g2.fillRect(0, 0, w, h); return image;}public BufferedImage getImage () {BufferedImage image = createImage(); Graphics2D g2 = (Graphics2D)image.getGraphics();StringBuilder sb = new StringBuilder();// 向图片中画4个字符for(int i = 0; i < 4; i++)  {String s = randomChar() + ""; sb.append(s); float x = i * 1.0F * w / 4; g2.setFont(randomFont()); g2.setColor(randomColor()); g2.drawString(s, x, h-5); }this.text = sb.toString(); drawLine(image); return image;}public String getText () {return text;}public static void output (BufferedImage image, OutputStream out) throws IOException {ImageIO.write(image, "JPEG", out);}}

在网页显示验证码图片：

package cn.itcast.vcode.servlet;import java.awt.image.BufferedImage;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import cn.itcast.vcode.utils.VerifyCode;public class VerifyCodeServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {VerifyCode vc = new VerifyCode();BufferedImage image = vc.getImage();//获取一次性验证码图片// 该方法必须在getImage()方法之后来调用//System.out.println(vc.getText());//获取图片上的文本VerifyCode.output(image, response.getOutputStream());//把图片写到指定流中// 把文本保存到session中，为LoginServlet验证做准备request.getSession().setAttribute("vCode", vc.getText());}}

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