java实现网页验证码功能

java实现网页验证码功能

本文实例为大家分享了java网页验证码的实现代码，供大家参考，具体内容如下

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, IOExceptiYkYorpCgVmon {

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();//相当于画笔

//画背景

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" %>

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