<%@page import="java.awt.image.BufferedImage"%> <%@page import="java.awt.*"%> <%@page import="java.util.*"%> <%@page import="javax.imageio.ImageIO" %> <%@ page language="java" contentType="image/jpeg; charset=UTF-8" pageEncoding="UTF-8"%> <%! //产生随机颜色 public Color getColor(){ Random ran=new Random();//random和math.random区别 int r=ran.nextInt(256); int g=ran.nextInt(256); int b=ran.nextInt(256); return new Color(r,g,b); } //产生验证码的值 public String getNum(){ //0~8999 -> 1000~9999 int ran=(int)(Math.random()*9000)+1000; return String.valueOf(ran); } %> <% //禁止缓存 防止验证码过期 response.setHeader("Pragma","no-cache"); response.setHeader("Cache-Control","no-cache"); response.setHeader("Expires","0"); //绘制验证码图片 BufferedImage image=new BufferedImage(80,30,BufferedImage.TYPE_INT_RGB); Graphics graphics=image.getGraphics(); graphics.fillRect(0,0,80,30); //绘制验证码 graphics.setFont(new Font("seif",Font.BOLD,20)); graphics.setColor(Color.black); String checkcode=getNum(); StringBuffer sb=new StringBuffer(); for(int i=0;i %>