jsp生成动态验证码

来源：互联网发布：组织架构数据库设计编辑：程序博客网时间：2024/05/16 08:23

<%@ page contentType="image/jpeg"
import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"%>
<%@ page contentType="image/jpeg" import="java.io.OutputStream"%>
<%
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
int width=65, height=19;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
OutputStream os=response.getOutputStream();
Random random = new Random();
g.setColor(new Color(255,255,255));
g.fillRect(0, 0, width, height);
g.setFont(new Font("Times New Roman",Font.PLAIN,18));
g.setColor(new Color(255,255,255));//--del
for (int i=0;i<40;i++)
{
     int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(12);
        int yl = random.nextInt(3);
        //g.setColor(new Color(random.nextInt(255),random.nextInt(255),random.nextInt(255)));
        g.setColor(new Color(255,255,255));//--del
        g.drawLine(x,y,x+xl,y+yl);
}
String sRand="";
for (int i=0;i<4;i++){
    int j = (random.nextInt(35) + 48);
    if(j > 57){
        j += 8;
    }
    if(j == 48){
    j += random.nextInt(7)+1;
    }
    if(j == 49){
    j += random.nextInt(7)+1;
    }
    if(j == 73){
    j += random.nextInt(7)+1;
    }
    if(j == 79){
    j += random.nextInt(7)+1;
    }
    if(j == 111){
    j += random.nextInt(7)+1;
    }

    String rand=String.valueOf((char)j);
    sRand+=rand;
    g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
    g.drawString(rand,13*i+6,16);
}
session.setAttribute("rand",sRand);
g.dispose();
ImageIO.write(image,"JPEG",os);
os.flush();
os.close();
os=null;
response.flushBuffer();
out.clear();
out = pageContext.pushBody();
%>