java實現網頁驗證碼

標籤：fun   title   set   next   graphics   ini   template   image   val   

Servlet:

package cn.bdqn.servlet;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;import java.awt.*;import java.awt.font.ImageGraphicAttribute;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;@WebServlet(name = "Servlet",urlPatterns = "/yanCode")public class Servlet extends HttpServlet {    public void doPost(javax.servlet.http.HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        this.doGet(request,response);    }    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        String s="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";        Random random = new Random();        int width=500;        int height=50;        BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);        Graphics graphics = image.getGraphics();//相當於畫筆        //畫背景        graphics.setColor(Color.gray);        graphics.fillRect(0,0,width,height);        graphics.setColor(Color.black);        for (int i = 0; i <4 ; i++) {            int index = random.nextInt(s.length());            String c = s.substring(index, index + 1);            graphics.drawString(c,width/5*(i+1),15);        }        ImageIO.write(image,"jpg",response.getOutputStream());    }}

　　jsp:

<%--  Created by IntelliJ IDEA.  User: Administrator  Date: 2017/10/10  Time: 13:04  To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><html>  <head>    <title>驗證碼</title>  </head>  <body>  <img src="yanCode" alt="驗證碼"  style="width: 500px;height:50px">  <input type="button" value="看不清,更換驗證碼" id="btn" onclick="changeCode();">  <script type="text/javascript" src="js/jquery.min.js">  </script>  <script type="text/javascript" >      function changeCode() {          $("img").attr(‘src‘, ‘yanCode?ts=‘ + new Date().getTime());      }  </script>  </body></html>

　　

java實現網頁驗證碼