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();

%>