javaWeb實現驗證碼--代碼超簡單

本文轉載自查看原文 2019-11-13 21:09 1203 Java/ javaWeb實現驗證碼/ 前端

方法一：

1、前端顯示

HTML：

<h3>驗證碼：</h3>
<input type="text" name="validationCode" id="validationCode" placeholder="請輸入驗證碼" lay-verify="required"> 
<img src="validate.jsp" id="validationCode_img" title="看不清?換一個" onclick="loadimage();return false;" name="validationCode_img" align="middle">

JS：

//加載驗證碼圖片，后面加時間可以保證每次頁面刷新時驗證碼也刷新
function loadimage(){
            document.getElementById("validationCode_img").src= "validate.jsp?time=" + new Date().getTime();
        }

2、用一個頁面生成驗證碼圖片，這里我用JSP頁面validate.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@page import="java.awt.image.BufferedImage"%>
<%@page import="java.awt.Graphics2D"%>
<%@page import="java.awt.Color"%>
<%@page import="java.awt.Font"%>
<%@page import="javax.imageio.ImageIO"%>
<%@page import="java.util.Random"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>驗證碼</title>
</head>
<body>
<%
    int width = 60;
    int height = 20;
    // 創建具有可訪問圖像數據緩沖區的Image
    BufferedImage buffImg = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
    Graphics2D g = buffImg.createGraphics();
    
    // 創建一個隨機數生成器
    Random random = new Random();
    
    g.setColor(Color.WHITE);
    g.fillRect(0, 0, width, height);
    
    // 創建字體，字體的大小應該根據圖片的高度來定
    Font font = new Font("Times New Roman", Font.PLAIN, 18);
    // 設置字體
    g.setFont(font);
    
    // 畫邊框
    g.setColor(Color.BLACK);
    g.drawRect(0, 0, width - 1, height - 1);
    
    // 隨機產生160條干擾線
    g.setColor(Color.LIGHT_GRAY);
    for (int i = 0; i < 160; i++) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int x1 = random.nextInt(12);
        int y1 = random.nextInt(12);
        g.drawLine(x, y, x + x1, y + y1);
    }
    
    // randomCode 用於保存隨機產生的驗證碼
    StringBuffer randomCode = new StringBuffer();
    int red = 0, green = 0, blue = 0;
    
    // 隨機產生4位數字的驗證碼
    for (int i = 0; i < 4; i++) {
        // 得到隨機產生的驗證碼數字
        String strRand = String.valueOf(random.nextInt(10));
    
        // 產生隨機的顏色分量來構造顏色值
        red = random.nextInt(110);
        green = random.nextInt(50);
        blue = random.nextInt(50);
    
        // 用隨機產生的顏色將驗證碼繪制到圖像中
        g.setColor(new Color(red, green, blue));
        g.drawString(strRand, 13 * i + 6, 16);
    
        randomCode.append(strRand);
    }
    
    // 將四位數字的驗證碼保存到session中
    //HttpSession session = request.getSession();
    session.setAttribute("randomCode", randomCode.toString());
    
    // 禁止圖像緩存
    response.setHeader("Pragma", "no-cache");
    response.setHeader("Cache-Control", "no-cache");
    response.setDateHeader("Expires", 0);
    
    response.setContentType("image/jpeg");
    // 將圖像輸出到servlet輸出流中
    ServletOutputStream sos = response.getOutputStream();
    ImageIO.write(buffImg, "jpeg", sos);
    sos.close();
    //sos = null;
    out.clear();
    out = pageContext.pushBody();
%>
</body>
</html>

3、在validate.jsp頁面中生成的驗證碼其實就是在java后端生成的，所以就存進了session中，我們只需要在用戶提交的時候將填寫的驗證碼帶到后端，這里我使用的是ajax請求，后端只需要判斷驗證碼是否和session中一樣就可以了。

方法二：

html代碼：

<div class="layui-form-item">
     <div class="layui-inline">
           <input type="text" name="verity" required lay-verify="required" placeholder="驗證碼" autocomplete="off" class="layui-input">
     </div>
     <div class="layui-inline">
          <img class="verifyImg" id="verifyImg" onclick="javascript:getvCode();"  />
          <script type="text/javascript">
                  getvCode();//初始化驗證碼，寫在此處減少驗證碼圖片出來的延時
          </script>
     </div>
</div>

js代碼：

/**
 * 獲取驗證碼
 * 將驗證碼寫到login.html頁面的id = verifyimg 的地方
 */
function getvCode() {
    $("#verifyImg").attr('src',timestamp("verifyCode"));
    
    
}
//為url添加時間戳
 function timestamp(url) {
    var getTimestamp = new Date().getTime();
    if (url.indexOf("?") > -1) {
        url = url + "&timestamp=" + getTimestamp
    } else {
        url = url + "?timestamp=" + getTimestamp
    }
    return url;
};

java代碼：

model層

//驗證碼
public class VerifyCode {
    private String code;
    private byte[] imgBytes;
    private long expireTime;
    public String getCode() {
        return code;
    }
    public void setCode(String code) {
        this.code = code;
    }
    public byte[] getImgBytes() {
        return imgBytes;
    }
    public void setImgBytes(byte[] imgBytes) {
        this.imgBytes = imgBytes;
    }
    public long getExpireTime() {
        return expireTime;
    }
    public void setExpireTime(long expireTime) {
        this.expireTime = expireTime;
    }
}

service層

import java.io.IOException;
import java.io.OutputStream;

import com.hongyang.webglasses.model.VerifyCode;

//驗證碼生成接口
public interface IVerifyCodeGen {
    /**
     * 生成驗證碼並返回code，將圖片寫的os中
     *
     * @param width
     * @param height
     * @param os
     * @return
     * @throws IOException
     */
    String generate(int width, int height, OutputStream os) throws IOException;
 
    /**
     * 生成驗證碼對象
     *
     * @param width
     * @param height
     * @return
     * @throws IOException
     */
    VerifyCode generate(int width, int height) throws IOException;
}

serviceimpl實現

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

import javax.imageio.ImageIO;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;

import com.hongyang.webglasses.model.VerifyCode;
import com.hongyang.webglasses.service.IVerifyCodeGen;
import com.hongyang.webglasses.util.RandomUtils;

@Service
public class SimpleCharVerifyCodeGenImpl implements IVerifyCodeGen {
    private static final Logger logger = LoggerFactory.getLogger(SimpleCharVerifyCodeGenImpl.class);
    private static final String[] FONT_TYPES = { "\u5b8b\u4f53", "\u65b0\u5b8b\u4f53", "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66" };
    private static final int VALICATE_CODE_LENGTH = 4;
    
    /**
     * 生成隨機字符
     *
     * @param width
     * @param height
     * @param os
     * @return
     * @throws IOException
     */
    @Override
    public String generate(int width, int height, OutputStream os) throws IOException {
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics graphics = image.getGraphics();
        fillBackground(graphics, width, height);
        String randomStr = RandomUtils.randomString(VALICATE_CODE_LENGTH);
        createCharacter(graphics, randomStr);
        graphics.dispose();
        //設置JPEG格式
        ImageIO.write(image, "JPEG", os);
        return randomStr;
    }

    /**
     * 驗證碼生成
     *
     * @param width
     * @param height
     * @return
     */
    @Override
    public VerifyCode generate(int width, int height) {
        VerifyCode verifyCode = null;
        try (
                //將流的初始化放到這里就不需要手動關閉流
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ) {
            String code = generate(width, height, baos);
            verifyCode = new VerifyCode();
            verifyCode.setCode(code);
            verifyCode.setImgBytes(baos.toByteArray());
        } catch (IOException e) {
            logger.error(e.getMessage(), e);
            verifyCode = null;
        }
        return verifyCode;
    }

    /**
     * 設置字符顏色大小
     *
     * @param g
     * @param randomStr
     */
    private void createCharacter(Graphics g, String randomStr) {
        char[] charArray = randomStr.toCharArray();
        for (int i = 0; i < charArray.length; i++) {
            //設置RGB顏色算法參數
            g.setColor(new Color(50 + RandomUtils.nextInt(100),
                    50 + RandomUtils.nextInt(100), 50 + RandomUtils.nextInt(100)));
            //設置字體大小，類型
            g.setFont(new Font(FONT_TYPES[RandomUtils.nextInt(FONT_TYPES.length)], Font.BOLD, 26));
            //設置x y 坐標
            g.drawString(String.valueOf(charArray[i]), 15 * i + 5, 19 + RandomUtils.nextInt(8));
        }
    }
    
    /**
     * 設置背景顏色及大小，干擾線
     *
     * @param graphics
     * @param width
     * @param height
     */
    private static void fillBackground(Graphics graphics, int width, int height) {
        // 填充背景
        System.setProperty("myColor", "#BBDAEE");
        graphics.setColor(Color.getColor("myColor"));
        //設置矩形坐標x y 為0
        graphics.fillRect(0, 0, width, height);

        // 加入干擾線條
        for (int i = 0; i < 8; i++) {
            //設置隨機顏色算法參數
            graphics.setColor(RandomUtils.randomColor(40, 150));
            Random random = new Random();
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            graphics.drawLine(x, y, x1, y1);
        }
    }
}

Controller層

@GetMapping("/verifyCode")
    public void verifyCode(HttpServletRequest request, HttpServletResponse response) {
        IVerifyCodeGen iVerifyCodeGen = new SimpleCharVerifyCodeGenImpl();
        try {
            //設置長寬
            VerifyCode verifyCode = iVerifyCodeGen.generate(80, 28);
            String code = verifyCode.getCode();
            //將VerifyCode綁定session，登錄控制器可從session中取出從而判斷用戶填的驗證碼是否正確
            request.getSession().setAttribute("VerifyCode", code);
            //設置響應頭
            response.setHeader("Pragma", "no-cache");
            //設置響應頭
            response.setHeader("Cache-Control", "no-cache");
            //在代理服務器端防止緩沖
            response.setDateHeader("Expires", 0);
            //設置響應內容類型
            response.setContentType("image/jpeg");
            response.getOutputStream().write(verifyCode.getImgBytes());
            response.getOutputStream().flush();
        } catch (IOException e) {
        }
    }

工具類

import java.awt.Color;
import java.util.Random;

//生成驗證碼隨機字符
public class RandomUtils extends org.apache.commons.lang3.RandomUtils{
    private static final char[] CODE_SEQ = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J',
            'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
            'X', 'Y', 'Z', '2', '3', '4', '5', '6', '7', '8', '9' };
 
    private static final char[] NUMBER_ARRAY = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
 
    private static Random random = new Random();
 
    public static String randomString(int length) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < length; i++) {
            sb.append(String.valueOf(CODE_SEQ[random.nextInt(CODE_SEQ.length)]));
        }
        return sb.toString();
    }
 
    public static String randomNumberString(int length) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < length; i++) {
            sb.append(String.valueOf(NUMBER_ARRAY[random.nextInt(NUMBER_ARRAY.length)]));
        }
        return sb.toString();
    }
 
    public static Color randomColor(int fc, int bc) {
        int f = fc;
        int b = bc;
        Random random = new Random();
        if (f > 255) {
            f = 255;
        }
        if (b > 255) {
            b = 255;
        }
        return new Color(f + random.nextInt(b - f), f + random.nextInt(b - f), f + random.nextInt(b - f));
    }
 
    public static int nextInt(int bound) {
        return random.nextInt(bound);
    }
}

效果圖：

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