下面imagecode方法是一個(gè)生成圖形驗(yàn)證碼的請(qǐng)求壶运，checkcode方法實(shí)現(xiàn)了對(duì)這個(gè)圖形驗(yàn)證碼的驗(yàn)證。從驗(yàn)證碼的生成到驗(yàn)證的過程中，驗(yàn)證碼是通過Session來(lái)保存的尿孔，并且設(shè)定一個(gè)驗(yàn)證碼的最長(zhǎng)有效時(shí)間為5分鐘。驗(yàn)證碼的生成規(guī)則是從0~9的數(shù)字中筹麸，隨機(jī)產(chǎn)生一個(gè)4位數(shù)活合，并增加一些干擾元素，最終組合成為一個(gè)圖形輸出

1物赶、驗(yàn)證碼生成類

import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.OutputStream;import java.util.HashMap;
import java.util.Map;import java.util.Random;

public class ImageCode {
    private static char mapTable[] = {
            '0', '1', '2', '3', '4', '5',
            '6', '7', '8', '9', '0', '1',
            '2', '3', '4', '5', '6', '7',
            '8', '9'};
    public static Map<String, Object> getImageCode(int width, int height, OutputStream os) {
        Map<String,Object> returnMap = new HashMap<String, Object>();
        if (width <= 0) width = 60;
        if (height <= 0) height = 20;
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        // 獲取圖形上下文
        Graphics g = image.getGraphics();
        //生成隨機(jī)類
        Random random = new Random();
        // 設(shè)定背景色
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        //設(shè)定字體
        g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
        // 隨機(jī)產(chǎn)生168條干擾線白指，使圖象中的認(rèn)證碼不易被其它程序探測(cè)到
        g.setColor(getRandColor(160, 200));
        for (int i = 0; i < 168; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }
        //取隨機(jī)產(chǎn)生的碼
        String strEnsure = "";
        //4代表4位驗(yàn)證碼,如果要生成更多位的認(rèn)證碼,則加大數(shù)值
        for (int i = 0; i < 4; ++i) {
            strEnsure += mapTable[(int) (mapTable.length * Math.random())];
            // 將認(rèn)證碼顯示到圖象中
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            //直接生成
            String str = strEnsure.substring(i, i + 1);
            g.drawString(str, 13 * i + 6, 16);
        }
        // 釋放圖形上下文
        g.dispose();
        returnMap.put("image",image);
        returnMap.put("strEnsure",strEnsure);
        return returnMap;
    }
    //給定范圍獲得隨機(jī)顏色
    static Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if (fc > 255) fc = 255;
        if (bc > 255) bc = 255;
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }
}

2、獲取驗(yàn)證碼API

@RequestMapping(value = "/images/imagecode")
public String imagecode(HttpServletRequest request, HttpServletResponse response) throws Exception {
    OutputStream os = response.getOutputStream();
    Map<String,Object> map = ImageCode.getImageCode(60, 20, os);
    String simpleCaptcha = "simpleCaptcha";
    request.getSession().setAttribute(simpleCaptcha, map.get("strEnsure").toString().toLowerCase());
    request.getSession().setAttribute("codeTime",new Date().getTime());
    try {
        ImageIO.write((BufferedImage) map.get("image"), "JPEG", os);
    } catch (IOException e) {
        return "";
    }
    return null;
}

3酵紫、驗(yàn)證驗(yàn)證碼API

@RequestMapping(value = "/checkcode")
@ResponseBody
public String checkcode(HttpServletRequest request, HttpSession session) throws Exception {
    String checkCode = request.getParameter("checkCode");
    Object cko = session.getAttribute("simpleCaptcha") ; //驗(yàn)證碼對(duì)象
    if(cko == null){
        request.setAttribute("errorMsg", "驗(yàn)證碼已失效告嘲，請(qǐng)重新輸入！");
        return "驗(yàn)證碼已失效奖地，請(qǐng)重新輸入橄唬！";
    }
    String captcha = cko.toString();
    Date now = new Date();
    Long codeTime = Long.valueOf(session.getAttribute("codeTime")+"");
    if(StringUtils.isEmpty(checkCode) || captcha == null ||  !(checkCode.equalsIgnoreCase(captcha))) {
        request.setAttribute("errorMsg", "驗(yàn)證碼錯(cuò)誤！");
        return "驗(yàn)證碼錯(cuò)誤参歹！";
    } else if ((now.getTime()-codeTime)/1000/60>5) {
        //驗(yàn)證碼有效時(shí)長(zhǎng)為5分鐘
        request.setAttribute("errorMsg", "驗(yàn)證碼已失效轧坎，請(qǐng)重新輸入！");
        return "驗(yàn)證碼已失效泽示，請(qǐng)重新輸入缸血！";
    }else {
        session.removeAttribute("simpleCaptcha");
        return "1";
    }
}