package web.servlet;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.awt.*;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;@WebServlet("/checkCodeServlet")public class CheckCodeServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { int width = 100; int height = 50; //1.创建对象，在内存中制作图片（验证码图片对象） BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); //2.美化图片 //2.1填充背景色 Graphics g = image.getGraphics();//画笔对象 g.setColor(Color.PINK);//设置画笔颜色 g.fillRect(0,0,width,height); //2.2画边框 g.setColor(Color.BLUE); g.drawRect(0,0,width-1,height-1); String str ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; //生成随机角标 Random ran = new Random(); for (int i = 1; i <=4 ; i++) { int index = ran.nextInt(str.length()); //获取字符 char c = str.charAt(index);//随机字符 //2.3写验证码 g.drawString(c+"",width/5*i,height/2); } //2.4画干扰线 for (int i = 0; i < 10; i++) { int x1 = ran.nextInt(width); int x2 = ran.nextInt(width); int y1 = ran.nextInt(height); int y2 = ran.nextInt(height); g.drawLine(x1,x2,y1,y2); } //3.将图片输出到页面展示 ImageIO.write(image,"jpg",response.getOutputStream()); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request,response); }}
Title window.onload = function (){ //1.获取图片对象 var img = document.getElementById("checkCode"); //2.绑定单击事件 img.onclick = function (){ //加时间戳 var date = new Date().getTime(); img.src = "/day15/checkCodeServlet?"+ date; } //1.获取图片对象 var g = document.getElementById("change"); //2.绑定单击事件 g.onclick = function (){ //加时间戳 var date = new Date().getTime(); g.src = "/day15/checkCodeServlet?"+ date; } } 
看不清，换一张
局座张召忠
