詳解Java實(shí)現(xiàn)后臺(tái)驗(yàn)證碼生成 完整實(shí)例代碼

/*驗(yàn)證碼輸入框*/
 
<input class="verifyInput"  name="verifyInput" placeholder="請(qǐng)輸入驗(yàn)證碼">   
 
 
/*驗(yàn)證碼圖片*/
 
<img class="verifyCode" onclick="changeCode()" src="https://atts.w3cschool.cn/attachments/getVerifyCode">
 
//src的getVerifyCode是后臺(tái)訪(fǎng)問(wèn)地址；項(xiàng)目為SSM框架。
 
 
/*點(diǎn)擊刷新驗(yàn)證碼*/
 
function changeCode(){
 
         var src = " getVerifyCode?"+new Date().getTime(); //加時(shí)間戳，防止瀏覽器利用緩存
 
    $('.verifyCode').attr("src",src);                  //jQuery寫(xiě)法
 
}

/* 獲取驗(yàn)證碼圖片*/
 
         @RequestMapping("/getVerifyCode ")
 
         public void getVerificationCode(HttpServletResponse response,HttpServletRequest request) {
 
                   try {
 
                            int width=200;
 
                            int height=69;
 
         BufferedImage verifyImg=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
 
//生成對(duì)應(yīng)寬高的初始圖片
 
                            String randomText = VerifyCode.drawRandomText(width,height,verifyImg);
 
//單獨(dú)的一個(gè)類(lèi)方法，出于代碼復(fù)用考慮，進(jìn)行了封裝。
 
//功能是生成驗(yàn)證碼字符并加上噪點(diǎn)，干擾線(xiàn)，返回值為驗(yàn)證碼字符                   
 
request.getSession().setAttribute("verifyCode", randomText);
 
                   response.setContentType("image/png");//必須設(shè)置響應(yīng)內(nèi)容類(lèi)型為圖片，否則前臺(tái)不識(shí)別
 
                 OutputStream os = response.getOutputStream(); //獲取文件輸出流    
 
                 ImageIO.write(verifyImg,"png",os);//輸出圖片流
 
                 os.flush();
 
                 os.close();//關(guān)閉流
 
                   } catch (IOException e) {
 
                            this.logger.error(e.getMessage());
 
                            e.printStackTrace();
 
                   }
 
         }

/*對(duì)圖片進(jìn)行處理的類(lèi)和方法*/
 
public class VerifyCode {  
 
    public static  String drawRandomText(int width,int height,BufferedImage verifyImg) {
             Graphics2D graphics = (Graphics2D)verifyImg.getGraphics();
             graphics.setColor(Color.WHITE);//設(shè)置畫(huà)筆顏色-驗(yàn)證碼背景色
             graphics.fillRect(0, 0, width, height);//填充背景
        graphics.setFont(new Font("微軟雅黑", Font.BOLD, 40));
        //數(shù)字和字母的組合
String baseNumLetter= = "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
 
        StringBuffer sBuffer = new StringBuffer();
        int x = 10;  //旋轉(zhuǎn)原點(diǎn)的 x 坐標(biāo)
        String ch = "";
        Random random = new Random();
        for(int i = 0;i < 4;i++){
                 graphics.setColor(getRandomColor());
            //設(shè)置字體旋轉(zhuǎn)角度
            int degree = random.nextInt() % 30;  //角度小于30度
            int dot = random.nextInt(baseNumLetter.length());
            ch = baseNumLetter.charAt(dot) + "";
            sBuffer.append(ch);
            //正向旋轉(zhuǎn)
            graphics.rotate(degree * Math.PI / 180, x, 45);
            graphics.drawString(ch, x, 45);
            //反向旋轉(zhuǎn)
            graphics.rotate(-degree * Math.PI / 180, x, 45);
            x += 48;
        }
        //畫(huà)干擾線(xiàn)
        for (int i = 0; i <6; i++) {
            // 設(shè)置隨機(jī)顏色
                 graphics.setColor(getRandomColor());
            // 隨機(jī)畫(huà)線(xiàn)
                 graphics.drawLine(random.nextInt(width), random.nextInt(height),
                                    random.nextInt(width), random.nextInt(height));
        }
        //添加噪點(diǎn)
        for(int i=0;i<30;i++){
                 int x1 = random.nextInt(width);
                 int y1 = random.nextInt(height);
                 graphics.setColor(getRandomColor());
                 graphics.fillRect(x1, y1, 2,2);
                 }
        return sBuffer.toString();
    }
    /**
     * 隨機(jī)取色
 
     */
    private static Color getRandomColor() {
        Random ran = new Random();
        Color color = new Color(ran.nextInt(256),
                ran.nextInt(256), ran.nextInt(256));
        return color;
    }
}