我在web.xml里配置了
<servlet>
<servlet-name>Getshowimg</servlet-name>
<servlet-class>servlet.Getshowimg</servlet-class>
</servlet> <servlet-mapping>
<servlet-name>Getshowimg</servlet-name>
<url-pattern>/Getshowimg</url-pattern>
</servlet-mapping>
还是不行.
<servlet>
<servlet-name>Getshowimg</servlet-name>
<servlet-class>servlet.Getshowimg</servlet-class>
</servlet> <servlet-mapping>
<servlet-name>Getshowimg</servlet-name>
<url-pattern>/Getshowimg</url-pattern>
</servlet-mapping>
还是不行.
import javax.servlet.http.*;import java.io.*;
import java.util.*;
import java.awt.Font;
import java.awt.Color;
import javax.imageio.ImageIO;import java.awt.image.BufferedImage;
import java.awt.Graphics;public class CodeFact extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
public void doGet(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);
response.setContentType("image/jpeg"); // 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(200, 250));
g.setColor(new Color(240,240,240));
g.fillRect(0, 0, width, height); // 设定字体
g.setFont(new Font("Arial", Font.PLAIN, 18)); // 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(4位数字)
String sRand = "";
for (int i = 0; i < 4; i++) {
String rand = String.valueOf(random.nextInt(10));
sRand += rand;
// 将认证码显示到图象中
g.setColor(new Color(100 + random.nextInt(150), 10 + random
.nextInt(100), 10 + random.nextInt(100))); // 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(rand, 13 * i + 6, 16);
}
// 画边框
// g.setColor(new Color(33, 66, 99));
// g.drawRect(0, 0, width - 1, height - 1);
// 将认证码存入SESSION
HttpSession session = request.getSession();
session.setAttribute("syj_"+UtilStatics.CODEFACT, sRand); // 图象生效
g.dispose(); // 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream()); }
/**
* 取得随机颜色
* @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);
}
/**
* 验证验证码是否正确
* @param request
* @param codeStr
* @return
*/
public static boolean validate(HttpServletRequest request, String codeStr) {
HttpSession session = request.getSession();
String verifyCode = (String) session.getAttribute("syj_"+UtilStatics.CODEFACT);
if (verifyCode == null || codeStr == null)
return false;
if (!verifyCode.equals(codeStr))
return false;
return true;
}
/**
* 验证验证码是否正确
* @param session
* @param codeStr
* @return
*/
public static boolean validate(HttpSession session, String codeStr) {
String verifyCode = (String) session.getAttribute("syj_"+UtilStatics.CODEFACT);
if (verifyCode == null || codeStr == null)
return false;
if (!verifyCode.equals(codeStr))
return false;
return true;
}
}
你看下我以前写的一个