Written in front

Some time ago, we all said that the environment is not good recently. Many companies are laying off employees. If they change jobs, they don't recommend easy naked words. But what I want to say is that my company has abuses, there are business needs that can't be done, and there are people who can't be recruited. Recently, I have been busy, but I still need to take a little time to do self-rewriting and recording. Recently, I have also written a simple small function, that is, the image verification code function of the landing interface.

1 Tool Class for Generating Verification Codes

public class RandomValidateCodeUtil {


    public static final String RANDOMCODEKEY= "RANDOMVALIDATECODEKEY";//key in session
    private String randString = "0123456789";//Random Generation of a Number-Only String private String
    //Private String randString = ABCDEFGHIJKLMNOPQRSTUVWXYZ; //Random generation of alphabetic strings
    //Private String randString = 0123456789 ABCDEFGHIJKLMNOPQRSTUVWXYZ; //Random Generation of Number and Letter Combination Strings
    private int width = 95;// Picture width
    private int height = 25;// Picture height
    private int lineSize = 40;// Number of interference lines
    private int stringNum = 4;// Number of randomly generated characters

    private static final Logger logger = LoggerFactory.getLogger(RandomValidateCodeUtil.class);

    private Random random = new Random();

    /**
     * Get font
     */
    private Font getFont() {
        return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
    }

    /**
     * Get color
     */
    private Color getRandColor(int fc, int bc) {
        if (fc > 255)
            fc = 255;
        if (bc > 255)
            bc = 255;
        int r = fc + random.nextInt(bc - fc - 16);
        int g = fc + random.nextInt(bc - fc - 14);
        int b = fc + random.nextInt(bc - fc - 18);
        return new Color(r, g, b);
    }

    /**
     * Generating Random Pictures
     */
    public void getRandcode(HttpServletRequest request, HttpServletResponse response) {
        HttpSession session = request.getSession();
        // The BufferedImage class is an Image class with buffers, and the Image class is a class for describing image information.
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
        Graphics g = image.getGraphics();// Graphics objects that generate Image objects can be changed to perform various rendering operations on images.
        g.fillRect(0, 0, width, height);//Picture size
        g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));//font size
        g.setColor(getRandColor(110, 133));//Font color
        // Drawing interference lines
        for (int i = 0; i <= lineSize; i++) {
            drowLine(g);
        }
        // Drawing random characters
        String randomString = "";
        for (int i = 1; i <= stringNum; i++) {
            randomString = drowString(g, randomString, i);
        }
        logger.info(randomString);
        //Save the generated random string to session
        session.removeAttribute(RANDOMCODEKEY);
        session.setAttribute(RANDOMCODEKEY, randomString);
        g.dispose();
        try {
            // Output the picture in memory to the client through the flow form
            ImageIO.write(image, "JPEG", response.getOutputStream());
        } catch (Exception e) {
            logger.error("Failed to stream images from memory to client>>>>   ", e);
        }

    }

    /**
     * Drawing strings
     */
    private String drowString(Graphics g, String randomString, int i) {
        g.setFont(getFont());
        g.setColor(new Color(random.nextInt(101), random.nextInt(111), random
                .nextInt(121)));
        String rand = String.valueOf(getRandomString(random.nextInt(randString
                .length())));
        randomString += rand;
        g.translate(random.nextInt(3), random.nextInt(3));
        g.drawString(rand, 13 * i, 16);
        return randomString;
    }

    /**
     * Drawing interference lines
     */
    private void drowLine(Graphics g) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(13);
        int yl = random.nextInt(15);
        g.drawLine(x, y, x + xl, y + yl);
    }

    /**
     * Get random characters
     */
    public String getRandomString(int num) {
        return String.valueOf(randString.charAt(num));
    }
}

This class doesn't need to be moved. It can be used directly.

2 page code

<!--html/bady Code-->

<div >
    <div >
        <div >
            <input  type="tel" id="verify_input" placeholder="Please enter the validation code" maxlength="4">
        </div>
    </div>
    <div >
        <a href="javascript:void(0);" title="Click on Replace Verification Code">
            <img id="imgVerify" src="login/getVerify" alt="Replacement of Verification Code" height="36" width="170" onclick="getVerify(this);">
        </a>
    </div>
    <input type="button" onclick="aVerify()" value="Submission">
</div>
</body>

<!--js Code in-->
<script type="text/javascript" src="./js/jquery.min.js"></script>
<script>

    //Get the authentication code
    /*function getVerify(obj){
        obj.src =  "login/getVerify?"+Math.random();//Native js mode
    }*/
	
	//Get the authentication code
    function getVerify() {
        // $("#imgCode").on("click", function() {
        $("#ImgVerify "). attr (" SRC ",'login / getVerify?'+ Math. random (); / / jQuery mode
        // });
    }

    function aVerify(){
        var value =$("#verify_input").val();
        // alert(value);
        $.ajax({
            async: false,
            type: 'post',
            url: 'login/checkVerify',
            dataType: "json",
            data: {
                verifyInput: value
            },
            success: function (result) {
                if (result) {
                    alert("success!");
                } else {
                    alert("failed!");
                }
                // window.location.reload();
                getVerify();
            }
        });
    }
</script>

3 Get code and verify code classes

@RestController
@RequestMapping("/login")
public class Picverifyaction {
    private final static Logger logger = LoggerFactory.getLogger(Picverifyaction.class);

    /**
     * Generating Verification Code
     */
    @RequestMapping(value = "/getVerify")
    public void getVerify(HttpServletRequest request, HttpServletResponse response) {
        try {
            response.setContentType("image/jpeg");//Set the appropriate type and tell the browser to output pictures
            response.setHeader("Pragma", "No-cache");//Set up response header information to tell browsers not to cache this content
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expire", 0);
            RandomValidateCodeUtil randomValidateCode = new RandomValidateCodeUtil();
            randomValidateCode.getRandcode(request, response);//Output Verification Code Picture Method
        } catch (Exception e) {
            logger.error("Failure to obtain authentication code>>>>   ", e);
        }
    }

    /**
     * Check Verification Code
     */
    @RequestMapping(value = "/checkVerify", method = RequestMethod.POST,headers = "Accept=application/json")
    public boolean checkVerify(@RequestParam String verifyInput, HttpSession session) {
        try{
            //Getting random numbers from session s
            String inputStr = verifyInput;
            String random = (String) session.getAttribute("RANDOMVALIDATECODEKEY");
            if (random == null) {
                return false;
            }
            if (random.equals(inputStr)) {
                return true;
            } else {
                return false;
            }
        }catch (Exception e){
            logger.error("Verification Code Failure", e);
            return false;
        }
    }

}

4 effect map town building

5 source code

Of course, the above code is only the core part. If you have any problems, you can download it by yourself in github. charmsongo

Reference resources: https://blog.csdn.net/Colton_Null/article/details/78744240