前端生成验证码图片utils

<%@ page language="java" contentType="text/html; charset=UTF-8"     pageEncoding="UTF-8"%> <%@ page import="java.util.Random"%> <%@ page import="java.io.OutputStream"%> <%@ page import="java.awt.Color"%> <%@ page import="java.awt.Font"%> <%@ page import="java.awt.Graphics"%> <%@ page import="java.awt.image.BufferedImage"%> <%@ page import="javax.imageio.ImageIO"%> <%     int width = 80;     int height = 32;     //create the image     BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);     Graphics g = image.getGraphics();     // set the background color     g.setColor(new Color(0xDCDCDC));     g.fillRect(0, 0, width, height);     // draw the border     g.setColor(Color.black);     g.drawRect(0, 0, width - 1, height - 1);     // create a random instance to generate the codes     Random rdm = new Random();     String hash1 = Integer.toHexString(rdm.nextInt());     // make some confusion     for (int i = 0; i < 50; i++) {         int x = rdm.nextInt(width);         int y = rdm.nextInt(height);         g.drawOval(x, y, 0, 0);     }     // generate a random code     String capstr = hash1.substring(0, 4);     session.setAttribute("validateCode", capstr);     g.setColor(new Color(0, 100, 0));     g.setFont(new Font("Candara", Font.BOLD, 24));     g.drawString(capstr, 8, 24);     g.dispose();     response.setContentType("image/jpeg");     out.clear();     out = pageContext.pushBody();     OutputStream strm = response.getOutputStream();     ImageIO.write(image, "jpeg", strm);     strm.close(); %>