java生成验证码的代码
谁能给我生成验证码的代码啊？求
[解决办法]
package com.softeem.servlet;import java.awt.Color;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class ImageServlet extends HttpServlet { @Override public void destroy() { super.destroy(); } @Override public void init() throws ServletException { super.init(); } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doPost(req, resp); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { // 禁止图像缓存,使得单击验证码可以刷新验证码图片 resp.setHeader("Pragma", "nocache"); resp.setHeader("Cache-Control", "no-cache"); resp.setDateHeader("Expires", 0); resp.setContentType("image/jpeg"); BufferedImage bim = new BufferedImage(70, 20, BufferedImage.TYPE_INT_RGB); Graphics2D gc = bim.createGraphics(); // 设置图片填充颜色 gc.setColor(Color.yellow); gc.fillRect(0, 0, 70, 20); // 设置边框颜色 gc.setColor(Color.pink); gc.drawRect(0, 0, 69, 19); // 产生4位随机数 Random rand = new Random(); StringBuffer sb = new StringBuffer(); // 设置干扰线颜色 gc.setColor(Color.cyan); for (int j = 0; j < 30; j++) { int x = rand.nextInt(70); int y = rand.nextInt(20); int x1 = rand.nextInt(6); int y1 = rand.nextInt(6); // 往图片里面画干扰线 gc.drawLine(x, y, x + x1, y + y1); } for (int i = 0; i < 4; i++) { int m = rand.nextInt(9); // 将生成的数字写入到图片中去,int转成string String str = String.valueOf(m); // 设置字体颜色 gc.setColor(Color.RED); gc.drawString(str, i * 10 + 20, 15); sb.append(m); } // 将stringbuffer转成string String sb1 = String.valueOf(sb); // 将生成的验证码的值放到session中去 req.getSession().setAttribute("code", sb1); // 将图片以流的形式输出 ServletOutputStream sos = resp.getOutputStream(); ImageIO.write(bim, "jpg", sos); sos.close(); }}
[解决办法]
后台JAVA代码：
import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;public class ImageAction extends HttpServlet { /** * 执行登陆的业务处理 * @param request:发送上来的请求 * @return destJsp：目标URL */ public void init() throws ServletException { super.init(); } public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{//设置页面不缓存 response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); //在内存中创建图象 int width = 60, height = 20; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); //获取图形上下文 Graphics g = image.getGraphics(); //生成随机类 Random random = new Random(); //设定背景色 g.setColor(getRandColor(220, 250)); g.fillRect(0, 0, width, height); //设定字体 g.setFont(new Font("Times New Roman", Font.PLAIN, 18)); //画边框 //g.drawRect(0,0,width-1,height-1); g.draw3DRect(0,0,width-1,height-1,true); //随机产生155条干扰线，使图象中的认证码不易被其它程序探测到 g.setColor(getRandColor(160, 200)); for (int i = 0; i < 155; i++) { int x = random.nextInt(width); int y = random.nextInt(height); int xl = random.nextInt(12); int yl = random.nextInt(12); g.drawLine(x, y, x + xl, y + yl); } // 取随机产生的认证码(6位数字) String sRand = ""; String s = "012345678901234567890123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ012345678901234567890123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; for (int i = 0; i < 4; i++) { char rand =s.charAt(random.nextInt(s.length())); sRand += rand; // 将认证码显示到图象中 g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110))); //调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成 g.drawString(String.valueOf(rand), 13 * i + 6, 16); } g.drawOval(0,12,60,11); // 将认证码存入SESSION request.getSession().setAttribute("rand", sRand); // 图象生效 g.dispose(); ServletOutputStream output = null; try { output = response.getOutputStream(); // 输出图象到页面 ImageIO.write(image, "JPEG", output); } catch (IOException e) { e.printStackTrace(); }finally{ output.close();} } /** * 生成随机颜色 */ private Color getRandColor(int fc, int bc) { Random random = new Random(); if (fc > 255) fc = 255; if (bc > 255) bc = 255; int r = fc + random.nextInt(bc - fc); int g = fc + random.nextInt(bc - fc); int b = fc + random.nextInt(bc - fc); return new Color(r, g, b); } }
[解决办法]
package com.qhit;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.log4j.Logger;
public class ShowCode extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
private static Logger log = Logger.getLogger(ShowCode.class);
//设置图形验证码中的字符串的字体的大小
private Font mFont = new Font("Arial Black", Font.PLAIN, 16);
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//生成服务器相应的service方法
//阻止生成的页面内容被缓存，保证每次重新生成随机验证码
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
response.setContentType("image/jpeg");
//指定图形验证码图片的大小；
int width = 80;//宽度
int height = 20;//高度
BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
//准备在图片中绘制内容
Graphics g = image.getGraphics();
Random random = new Random();
g.setColor(getRandColor(200, 250));
g.fillRect(1, 1, width - 1, height - 1);
g.setColor(new Color(102, 102, 102));
g.drawRect(0, 0, width - 1, height - 1);
g.setFont(mFont);
g.setColor(getRandColor(160, 200));
//生成随机线条
for (int i = 0; i < 155; i++) {
int x = random.nextInt(width - 1);
int y = random.nextInt(height - 1);
int xl = random.nextInt(6) + 1;
int yl = random.nextInt(12) + 1;
g.drawLine(x, y, x + xl, y + yl);
}
for (int i = 0; i < 70; i++) {
int x = random.nextInt(width - 1);
int y = random.nextInt(height - 1);
int xl = random.nextInt(12) + 1;
int yl = random.nextInt(6) + 1;
g.drawLine(x, y, x - xl, y - yl);
}
String sRand = "";
//生成随机的字符串并加入到图片中
int LEN = 4; //控制随机码的长度
for (int i = 0; i < LEN; i++) {
String tmp = getRandomChar();
sRand += tmp;
g.setColor(new Color(20 + random.nextInt(110), 20 + random
.nextInt(110), 20 + random.nextInt(110)));
g.drawString(tmp, 15 * i + 10, 15);
}
HttpSession session = request.getSession(true);
log.info("随机生成的字符串为"+sRand);
System.out.println("随机生成的字符串为"+sRand);
//将其自动转换为小写。也就是说用户在输入验证码的时候，不需要区分大小写，方便输入。
session.setAttribute("code", sRand.toLowerCase());
log.info("从session中取出来"+session.getAttribute("code"));
g.dispose();
ImageIO.write(image, "JPEG", response.getOutputStream());
}
/**
* 生成随机颜色
* @param fc
* @param bc
* @return
*/
private Color getRandColor(int fc, int bc) {
Random random = new Random();
if (fc > 255)
fc = 255;
if (bc > 255)
bc = 255;
int r = fc + random.nextInt(bc - fc);
int g = fc + random.nextInt(bc - fc);
int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}
/**
* 随机生成字符串
* @return
*/
private String getRandomChar() {
int rand = (int) Math.round(Math.random() * 2);
long itmp = 0;
char ctmp = '\u0000';
switch (rand) {
case 1:
itmp = Math.round(Math.random() * 25 + 65);
ctmp = (char) itmp;
return String.valueOf(ctmp);
case 2:
itmp = Math.round(Math.random() * 25 + 97);
ctmp = (char) itmp;
return String.valueOf(ctmp);
default:
itmp = Math.round(Math.random() * 9);
return String.valueOf(itmp);
}
}
}