Java web图片验证功能实现二

来源：互联网发布：软件测试搭建环境编辑：程序博客网时间：2024/05/24 02:12

上一篇实现的是最简单的图片验证，本文要实现复杂一点的：图片是旋转的，并通过一个注册实例把图片验证嵌套在网页中

实现图片旋转功能的代码为：

//写字母String content = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcedfghijklmnopqrstuvwxyz1234567890";Random random = new Random();Graphics2D graphics2D = (Graphics2D)graphics;//设置字体颜色graphics2D.setColor(Color.red);//设置字体及大小graphics2D.setFont(new Font("宋体", Font.BOLD, 20));int x=20;int y=20;for(int i = 0; i < 4; i++){int index = random.nextInt(content.length());char letter = content.charAt(index);double jiaodu = random.nextInt(60)-30;double theta = jiaodu/360*2*Math.PI;graphics2D.rotate(theta, x, y);graphics2D.drawString(letter+" ", x, y);graphics2D.rotate(-theta, x, y);x = x+20;}

实现带旋转图片验证功能的servlet代码为：

package com.lsgjzhuwei.servlet.response;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class VerificationCode */@WebServlet(asyncSupported = true, urlPatterns = { "/VerificationCode" })public class VerificationCode extends HttpServlet {private static final long serialVersionUID = 1L;           /**     * @see HttpServlet#HttpServlet()     */    public VerificationCode() {        super();        // TODO Auto-generated constructor stub    }/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// TODO Auto-generated method stubint width = 120;int height = 30;//创建一张内存中的缓存图片BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);///背景色//通过graphics绘制图像Graphics graphics = bufferedImage.getGraphics();//设置颜色graphics.setColor(Color.yellow);//填充graphics.fillRect(0, 0, width, height);///画边框graphics.setColor(Color.blue);graphics.drawRect(0, 0, width-1, height-1);//写字母String content = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcedfghijklmnopqrstuvwxyz1234567890";Random random = new Random();Graphics2D graphics2D = (Graphics2D)graphics;//设置字体颜色graphics2D.setColor(Color.red);//设置字体及大小graphics2D.setFont(new Font("宋体", Font.BOLD, 20));int x=20;int y=20;for(int i = 0; i < 4; i++){int index = random.nextInt(content.length());char letter = content.charAt(index);double jiaodu = random.nextInt(60)-30;double theta = jiaodu/360*2*Math.PI;graphics2D.rotate(theta, x, y);graphics2D.drawString(letter+" ", x, y);graphics2D.rotate(-theta, x, y);x = x+20;}//绘制干扰线int x1;int x2;int y1;int y2;graphics.setColor(Color.LIGHT_GRAY);for(int i = 0;i <50;i++){x1=random.nextInt(width);x2=random.nextInt(width);y1=random.nextInt(height);y2=random.nextInt(height);graphics.drawLine(x1, y1, x2, y2);}//将图片输出到浏览器//将内存的图片通过浏览器输出流输出成jpg图片ImageIO.write(bufferedImage, "jpg", response.getOutputStream());}/** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// TODO Auto-generated method stub}}

下面是新建HTML页面，并添加简单的注册按钮，源码如下：

<!DOCTYPE html><html><head><meta charset="UTF-8"><title>Insert title here</title></head><body><form>输入用户名<input type="text"/><br/>请输入密码<input type="password"/><br/>请输入验证码<input type="text" name ="checkcode"><img src="/day06/VerificationCode"/> <br/><input type="submit" value="注册"/></form></body></html>

系统运行界面如下：

下面实现复杂点的功能：单击图片验证码的时候验证码刷新

修改HTML页面代码如下：

<!DOCTYPE html><html><head><meta charset="UTF-8"><script type="text/javascript">function change(){//alert("1");//重新加载生成图片document.getElementById("myimg").src="/day06/VerificationCode?"+new Date().getTime();//alert(document.getElementById("myimg").src);}</script><title>Insert title here</title></head><body><form>输入用户名<input type="text"/><br/>请输入密码<input type="password"/><br/>请输入验证码<input type="text" name ="checkcode"><img src="/day06/VerificationCode" onclick="change()" id="myimg" style="cursor:pointer"/> <br/><input type="submit" value="注册"/></form></body></html>

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