簡單實用的驗證碼工具

1、直接上工具類代碼

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Date;
import java.util.Random;

/**
 * @Auther: liuzujie
 * @Date: ***
 * @Desc: 生成驗證碼
 */
public class ValidateCodeUtil {
    private int width = 160;
    private int height = 40;
    private int codeCount = 5;
    private int lineCount = 150;
    private String code = null;
    private BufferedImage buffImg = null;
    private char[] codeSequence = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '1', '2', '3', '4', '5', '6', '7', '8', '9'};

    public ValidateCodeUtil() {
        createCode();
    }

    public ValidateCodeUtil(int width, int height) {
        this.width = width;
        this.height = height;
        createCode();
    }

    public ValidateCodeUtil(int width, int height, int codeCount, int lineCount) {
        this.width = width;
        this.height = height;
        this.codeCount = codeCount;
        this.lineCount = lineCount;
        createCode();
    }

    private void createCode() {
        int x = 0;
        int fontHeight = 0;
        int codeY = 0;
        int red = 0;
        int green = 0;
        int blue = 0;

        x = this.width / (this.codeCount + 2);
        fontHeight = this.height - 2;
        codeY = this.height - 4;


        this.buffImg = new BufferedImage(this.width, this.height, 1);
        Graphics2D g = this.buffImg.createGraphics();

        Random random = new Random();

        g.setColor(Color.WHITE);
        g.fillRect(0, 0, this.width, this.height);

        Font font = new Font("Fixedsys", 0, fontHeight);

        g.setFont(font);
        for (int i = 0; i < this.lineCount; i++) {
            int xs = random.nextInt(this.width);
            int ys = random.nextInt(this.height);
            int xe = xs + random.nextInt(this.width / 8);
            int ye = ys + random.nextInt(this.height / 8);


            red = random.nextInt(255);
            green = random.nextInt(255);
            blue = random.nextInt(255);
            g.setColor(new Color(red, green, blue));
            g.drawLine(xs, ys, xe, ye);
        }
        StringBuffer randomCode = new StringBuffer();
        for (int i = 0; i < this.codeCount; i++) {
            String strRand = String.valueOf(this.codeSequence[random.nextInt(this.codeSequence.length)]);

            red = random.nextInt(255);
            green = random.nextInt(255);
            blue = random.nextInt(255);
            g.setColor(new Color(red, green, blue));
            g.drawString(strRand, (i + 1) * x, codeY);

            randomCode.append(strRand);
        }
        this.code = randomCode.toString();
    }

    public void write(String path)
            throws IOException {
        OutputStream sos = new FileOutputStream(path);
        write(sos);
    }

    public void write(OutputStream sos)
            throws IOException {
        ImageIO.write(this.buffImg, "png", sos);
        sos.close();
    }

    public BufferedImage getBuffImg() {
        return this.buffImg;
    }

    public String getCode() {
        return this.code;
    }

    public static void main(String[] args) { //測試
        ValidateCodeUtil vCode = new ValidateCodeUtil(160, 40, 5, 150);
        try {
            String path = "D:/" + new Date().getTime() + ".png";
            System.out.println(vCode.getCode() + " >" + path);
            vCode.write(path);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

 

2、提供給前端的接口代碼

 

   @RequestMapping({"/getCaptcha"})
    public void captcha(HttpServletRequest request, HttpServletResponse response, HttpSession session)
            throws IOException {
        response.setDateHeader("Expires", 0L);
        response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
        response.addHeader("Cache-Control", "post-check=0, pre-check=0");
        response.setHeader("Pragma", "no-cache");
        response.setContentType("image/jpeg");

        ValidateCodeUtil vCode = new ValidateCodeUtil(160, 40, 1, 25);
        String code = vCode.getCode();
 
        ServletOutputStream out = response.getOutputStream();
        vCode.write(out);
    }

3、前端

 

<div class="img-wrap login-code" οnclick="getValidateCode()"> <img id="canvasValidate" /></div>

 

function getValidateCode(){ //後面加個時間參數可以解決IE下不刷新的問題
       $("#canvasValidate").attr("src",top.global.ctx+"/captcha?"+new Date().getTime());
   }