JAVA 배경 인증 코드 생 성

전재 기록

package com.zbmes.common.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

public class CaptchaUtils {

	private static int width = 90;//      width
	private static int height = 30;//      height
	private static int codeCount = 4;//              
	private static int xx = 15;
	private static int fontHeight = 20;//       
	private static int codeY = 24;//      
	private static char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G',
			'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
			'U', 'V', 'W', 'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6',
			'7', '8', '9' };

	/**
	 *     map   code        codePic       BufferedImage  
	 * 
	 * @return
	 */
	public static Map generateCodeAndPic() {
		//     buffer
		BufferedImage buffImg = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB);
		// Graphics2D gd = buffImg.createGraphics();
		// Graphics2D gd = (Graphics2D) buffImg.getGraphics();
		Graphics gd = buffImg.getGraphics();
		//            
		Random random = new Random();
		//         
		gd.setColor(Color.WHITE);
		gd.fillRect(0, 0, width, height);

		//     ，                。
		Font font = new Font("Fixedsys", Font.BOLD, fontHeight);
		//     。
		gd.setFont(font);

		//    。
		gd.setColor(Color.BLACK);
		gd.drawRect(0, 0, width - 1, height - 1);

		//     20    ，                  。
		gd.setColor(Color.BLACK);
		for (int i = 0; i < 20; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			gd.drawLine(x, y, x + xl, y + yl);
		}

		// randomCode            ，           。
		StringBuffer randomCode = new StringBuffer();
		int red = 0, green = 0, blue = 0;

		//     codeCount      。
		for (int i = 0; i < codeCount; i++) {
			//             。
			String code = String.valueOf(codeSequence[random.nextInt(36)]);
			//                ，                 。
			red = random.nextInt(255);
			green = random.nextInt(255);
			blue = random.nextInt(255);

			//                   。
			gd.setColor(new Color(red, green, blue));
			gd.drawString(code, (i + 1) * xx, codeY);

			//               。
			randomCode.append(code);
		}
		Map map = new HashMap();
		//      
		map.put("code", randomCode);
		//         BufferedImage  
		map.put("codePic", buffImg);
		return map;
	}

	/*
	 * public static void main(String[] args) throws Exception { //         
	 * OutputStream out = new
	 * FileOutputStream("G://img"+System.currentTimeMillis()+".jpg");
	 * Map map = CaptchaUtils.generateCodeAndPic();
	 * ImageIO.write((RenderedImage) map.get("codePic"), "jpeg", out);
	 * System.out.println("      ："+map.get("code")); }
	 */

}

인증 코드 를 session 에 저장 하고 로그 인 할 때 체크 섬 을 꺼 냅 니 다.

@RequestMapping("/captcha")
	@ResponseBody
    public void doGet(HttpServletRequest req, HttpServletResponse resp){
        //                  
        Map codeMap = CaptchaUtils.generateCodeAndPic();
        //             Session 。
        HttpSession session = req.getSession();
        session.setAttribute("captcha", codeMap.get("code").toString());
        //       。
        resp.setHeader("Pragma", "no-cache");
        resp.setHeader("Cache-Control", "no-cache");
        resp.setDateHeader("Expires", -1);
        resp.setContentType("image/jpeg");
        //       Servlet    。
        ServletOutputStream sos;
        try {
            sos = resp.getOutputStream();
            ImageIO.write((RenderedImage) codeMap.get("codePic"), "jpeg", sos);
            sos.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }