「java图片验证码生成」图片验证码的实现
本篇文章给大家谈谈java图片验证码生成，以及图片验证码的实现对应的知识点，希望对各位有所帮助，不要忘了收藏本站喔。
本文目录一览：
- 1、java验证码怎么做
- 2、java 登陆时的验证码怎么做？
- 3、Java如何实现验证码验证功能
- 4、如何用Java代码段生成四位数字加字母的验证码？
- 5、怎么用Java代码实现一个验证码，求具体实现方法
- 6、求一个Java语言编写的gif动态验证码 就是百度注册用户的那种
java验证码怎么做
下面是实现验证码中，最难的一块----画图片，我这个支持中文验证码，我把代码贴上，如果要整个项目的话，我发给你。
package SMART.JRSOFT.IDENTTIFYINGCODE;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.*;
import java.awt.*;
import java.awt.image.*;
import javax.imageio.*;
import javax.servlet.http.*;
import org.apache.commons.lang.RandomStringUtils;
public class getimg extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
/**
* Constructor of the object.
*/
public getimg() {
super();
}
/**
* Destruction of the servlet. br
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. br
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
// 定义图片长度和宽度
int width=176, height=30;
// 创建内存图像
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
Random random = new Random();
// 验证码图形显示为数字和英文字母
g.setColor(getRandColor(200,250));
g.fillRect(0, 0, width, height);
g.setFont(new Font("Times New Roman",Font.BOLD,18));
g.setColor(new Color(255,255,255));
g.drawRect(0,0,width-1,height-1);
g.setColor(getRandColor(160,200));
for (int i=0;i155;i++)
{
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x,y,x+xl,y+yl);
}
// 随机获取四位字母或数字型字符
String s = RandomStringUtils.random(4,false,true);
g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
// 将字符画到图片上
g.drawString(s,6,20);
/* 显示汉字验证码
// 设置备选汉字，剔除一些不雅的汉字
String base = "\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db\u5df2\u6240\u654c\u4e4b\u6700\u5149\u4ea7\u60c5\u8def\u5206\u603b\u6761\u767d\u8bdd\u4e1c\u5e2d\u6b21\u4eb2\u5982\u88ab\u82b1\u53e3\u653e\u513f\u5e38\u6c14\u4e94\u7b2c\u4f7f\u5199\u519b\u5427\u6587\u8fd0\u518d\u679c\u600e\u5b9a\u8bb8\u5feb\u660e\u884c\u56e0\u522b\u98de\u5916\u6811\u7269\u6d3b\u90e8\u95e8\u65e0\u5f80\u8239\u671b\u65b0\u5e26\u961f\u5148\u529b\u5b8c\u5374\u7ad9\u4ee3\u5458\u673a\u66f4\u4e5d\u60a8\u6bcf\u98ce\u7ea7\u8ddf\u7b11\u554a\u5b69\u4e07\u5c11\u76f4\u610f\u591c\u6bd4\u9636\u8fde\u8f66\u91cd\u4fbf\u6597\u9a6c\u54ea\u5316\u592a\u6307\u53d8\u793e\u4f3c\u58eb\u8005\u5e72\u77f3\u6ee1\u65e5\u51b3\u767e\u539f\u62ff\u7fa4\u7a76\u5404\u516d\u672c\u601d\u89e3\u7acb\u6cb3\u6751\u516b\u96be\u65e9\u8bba\u5417\u6839\u5171\u8ba9\u76f8\u7814\u4eca\u5176\u4e66\u5750\u63a5\u5e94\u5173\u4fe1\u89c9\u6b65\u53cd\u5904\u8bb0\u5c06\u5343\u627e\u4e89\u9886\u6216\u5e08\u7ed3\u5757\u8dd1\u8c01\u8349\u8d8a\u5b57\u52a0\u811a\u7d27\u7231\u7b49\u4e60\u9635\u6015\u6708\u9752\u534a\u706b\u6cd5\u9898\u5efa\u8d76\u4f4d\u5531\u6d77\u4e03\u5973\u4efb\u4ef6\u611f\u51c6\u5f20\u56e2\u5c4b\u79bb\u8272\u8138\u7247\u79d1\u5012\u775b\u5229\u4e16\u521a\u4e14\u7531\u9001\u5207\u661f\u5bfc\u665a\u8868\u591f\u6574\u8ba4\u54cd\u96ea\u6d41\u672a\u573a\u8be5\u5e76\u5e95\u6df1\u523b\u5e73\u4f1f\u5fd9\u63d0\u786e\u8fd1\u4eae\u8f7b\u8bb2\u519c\u53e4\u9ed1\u544a\u754c\u62c9\u540d\u5440\u571f\u6e05\u9633\u7167\u529e\u53f2\u6539\u5386\u8f6c\u753b\u9020\u5634\u6b64\u6cbb\u5317\u5fc5\u670d\u96e8\u7a7f\u5185\u8bc6\u9a8c\u4f20\u4e1a\u83dc\u722c\u7761\u5174\u5f62\u91cf\u54b1\u89c2\u82e6\u4f53\u4f17\u901a\u51b2\u5408\u7834\u53cb\u5ea6\u672f\u996d\u516c\u65c1\u623f\u6781\u5357\u67aa\u8bfb\u6c99\u5c81\u7ebf\u91ce\u575a\u7a7a\u6536\u7b97\u81f3\u653f\u57ce\u52b3\u843d\u94b1\u7279\u56f4\u5f1f\u80dc\u6559\u70ed\u5c55\u5305\u6b4c\u7c7b\u6e10\u5f3a\u6570\u4e61\u547c\u6027\u97f3\u7b54\u54e5\u9645\u65e7\u795e\u5ea7\u7ae0\u5e2e\u5566\u53d7\u7cfb\u4ee4\u8df3\u975e\u4f55\u725b\u53d6\u5165\u5cb8\u6562\u6389\u5ffd\u79cd\u88c5\u9876\u6025\u6797\u505c\u606f\u53e5\u533a\u8863\u822c\u62a5\u53f6\u538b\u6162\u53d4\u80cc\u7ec6";
// 备选汉字的长度
int length = base.length();
// 设定图像背景色(因为是做背景，所以偏淡)
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
// 备选字体
String[] fontTypes = {"\u5b8b\u4f53", "\u65b0\u5b8b\u4f53", "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66"};
int fontTypesLength = fontTypes.length;
// 在图片背景上增加噪点
g.setColor(getRandColor(160, 200));
g.setFont(new Font("Times New Roman", Font.PLAIN, 14));
for (int i = 0; i 6; i++) {
g.drawString("*********************************************", 0, 5 * (i + 2));
}
String s = "";
for (int i = 0; i 6; i++) {
int start = random.nextInt(length);
String rand = base.substring(start, start + 1);
s += rand;
//设置字体的颜色
g.setColor(getRandColor(10, 150));
//设置字体
g.setFont(new Font(fontTypes[random.nextInt(fontTypesLength)], Font.BOLD, 18 + random.nextInt(6)));
//将此汉字画到图片上
g.drawString(rand, 24 * i + 10 + random.nextInt(8), 24);
}
*/
HttpSession session=request.getSession();
session.setAttribute("rand",s);
g.dispose();
ImageIO.write(image, "JPEG", response.getOutputStream());
}
Color getRandColor(int fc,int bc){
Random random = new Random();
if(fc255) fc=255;
if(bc255) bc=255;
int r=fc+random.nextInt(bc-fc);
int g=fc+random.nextInt(bc-fc);
int b=fc+random.nextInt(bc-fc);
return new Color(r,g,b);
}
/**
* The doPost method of the servlet. br
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\"");
out.println("HTML");
out.println(" HEADTITLEA Servlet/TITLE/HEAD");
out.println(" BODY");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the POST method");
out.println(" /BODY");
out.println("/HTML");
out.flush();
out.close();
}
/**
* Initialization of the servlet. br
*
* @throws ServletException if an error occure
*/
public void init() throws ServletException {
// Put your code here
}
}
java 登陆时的验证码怎么做？
后台写一个生成图片随机的代码，生成图片给前台。切换图片的时候，使用ajax获取图片数据就行。
附上生成图片的代码
public class ValidateCode {
private int width=180;
private int height=60;
private int codeCount = 4;
private int x = 0;
private int codeY;
private String Code;
private BufferedImage buffImg;
static char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
'X', 'Y', 'Z','a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
'x', 'y', 'z', 'o', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
private int fontHeight;
public ValidateCode() {
x = width / (codeCount + 2);
fontHeight = height - 2;
codeY = height - 4;
CreateCode();
}
public void CreateCode(){
// 定义图像buffer
BufferedImage buffImg = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
Graphics2D g = buffImg.createGraphics();
// 创建一个随机数生成器类
Random random = new Random();
// 将图像填充为白色
g.setColor(Color.WHITE);
g.fillRect(0, 0, width, height);
// 创建字体，字体的大小应该根据图片的高度来定。
Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);
// 设置字体。
g.setFont(font);
// 画边框。
g.setColor(Color.BLACK);
g.drawRect(0, 0, width - 1, height - 1);
// randomCode用于保存随机产生的验证码，以便用户登录后进行验证。
StringBuffer randomCode = new StringBuffer();
int red = 0, green = 0, blue = 0;
// 随机产生codeCount数字的验证码。
for (int i = 0; i codeCount; i++) {
// 得到随机产生的验证码数字。
String strRand = String.valueOf(codeSequence[random.nextInt(62)]);
// 产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同。
red = random.nextInt(255);
green = random.nextInt(255);
blue = random.nextInt(255);
// 用随机产生的颜色将验证码绘制到图像中。
g.setColor(new Color(red, green, blue));
g.drawString(strRand, (i ) * x+20, codeY);
// 将产生的四个随机数组合在一起。
randomCode.append(strRand);
}
this.Code=randomCode.toString().toUpperCase();
this.buffImg=buffImg;
}
public String getCode() {
return Code;
}
public void setCode(String code) {
Code = code;
}
public BufferedImage getBuffImg() {
return buffImg;
}
public void setBuffImg(BufferedImage buffImg) {
this.buffImg = buffImg;
}
}
Java如何实现验证码验证功能
Java如何实现验证码验证功能呢？日常生活中，验证码随处可见，他可以在一定程度上保护账号安全，那么他是怎么实现的呢？
Java实现验证码验证功能其实非常简单：用到了一个Graphics类在画板上绘制字母，随机选取一定数量的字母随机生成，然后在画板上随机生成几条干扰线。
首先，写一个验证码生成帮助类，用来绘制随机字母：
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
public final class GraphicHelper {
/**
* 以字符串形式返回生成的验证码，同时输出一个图片
*
* @param width
* 图片的宽度
* @param height
* 图片的高度
* @param imgType
* 图片的类型
* @param output
* 图片的输出流(图片将输出到这个流中)
* @return 返回所生成的验证码(字符串)
*/
public static String create(final int width, final int height, final String imgType, OutputStream output) {
StringBuffer sb = new StringBuffer();
Random random = new Random();
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics graphic = image.getGraphics();
graphic.setColor(Color.getColor("F8F8F8"));
graphic.fillRect(0, 0, width, height);
Color[] colors = new Color[] { Color.BLUE, Color.GRAY, Color.GREEN, Color.RED, Color.BLACK, Color.ORANGE,
Color.CYAN };
// 在 "画板"上生成干扰线条 ( 50 是线条个数)
for (int i = 0; i 50; i++) {
graphic.setColor(colors[random.nextInt(colors.length)]);
final int x = random.nextInt(width);
final int y = random.nextInt(height);
final int w = random.nextInt(20);
final int h = random.nextInt(20);
final int signA = random.nextBoolean() ? 1 : -1;
final int signB = random.nextBoolean() ? 1 : -1;
graphic.drawLine(x, y, x + w * signA, y + h * signB);
}
// 在 "画板"上绘制字母
graphic.setFont(new Font("Comic Sans MS", Font.BOLD, 30));
for (int i = 0; i 6; i++) {
final int temp = random.nextInt(26) + 97;
String s = String.valueOf((char) temp);
sb.append(s);
graphic.setColor(colors[random.nextInt(colors.length)]);
graphic.drawString(s, i * (width / 6), height - (height / 3));
}
graphic.dispose();
try {
ImageIO.write(image, imgType, output);
} catch (IOException e) {
e.printStackTrace();
}
return sb.toString();
}
}
接着，创建一个servlet，用来固定图片大小，以及处理验证码的使用场景，以及捕获页面生成的验证码（捕获到的二维码与用户输入的验证码一致才能通过）。
import java.io.OutputStream;
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 javax.servlet.http.HttpSession;
@WebServlet(urlPatterns = "/verify/regist.do" )
public class VerifyCodeServlet extends HttpServlet {
private static final long serialVersionUID = 3398560501558431737L;
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 获得 当前请求 对应的 会话对象
HttpSession session = request.getSession();
// 从请求中获得 URI ( 统一资源标识符 )
String uri = request.getRequestURI();
System.out.println("hello : " + uri);
final int width = 180; // 图片宽度
final int height = 40; // 图片高度
final String imgType = "jpeg"; // 指定图片格式 (不是指MIME类型)
final OutputStream output = response.getOutputStream(); // 获得可以向客户端返回图片的输出流
// (字节流)
// 创建验证码图片并返回图片上的字符串
String code = GraphicHelper.create(width, height, imgType, output);
System.out.println("验证码内容: " + code);
// 建立 uri 和 相应的 验证码 的关联 ( 存储到当前会话对象的属性中 )
session.setAttribute(uri, code);
System.out.println(session.getAttribute(uri));
}
}
接着写一个HTML注册页面用来检验一下：
html
head
meta charset="UTF-8"
title注册/title
link rel="stylesheet" href="styles/general.css"
link rel="stylesheet" href="styles/cell.css"
link rel="stylesheet" href="styles/form.css"
script type="text/javascript" src="js/ref.js"/script
style type="text/css"
.logo-container {
margin-top: 50px ;
}
.logo-container img {
width: 100px ;
}
.message-container {
height: 80px ;
}
.link-container {
height: 40px ;
line-height: 40px ;
}
.link-container a {
text-decoration: none ;
}
/style
/head
body
div class="container form-container"
form action="/wendao/regist.do" method="post"
div class="form" !-- 注册表单开始 --
div class="form-row"
span class="cell-1"
i class="fa fa-user"/i
/span
span class="cell-11" style="text-align: left;"
input type="text" name="username" placeholder="请输入用户名"
/span
/div
div class="form-row"
span class="cell-1"
i class="fa fa-key"/i
/span
span class="cell-11" style="text-align: left;"
input type="password" name="password" placeholder="请输入密码"
/span
/div
div class="form-row"
span class="cell-1"
i class="fa fa-keyboard-o"/i
/span
span class="cell-11" style="text-align: left;"
input type="password" name="confirm" placeholder="请确认密码"
/span
/div
div class="form-row"
span class="cell-7"
input type="text" name="verifyCode" placeholder="请输入验证码"
/span
span class="cell-5" style="text-align: center;"
img src="/demo/verify/regist.do" onclick="myRefersh(this)"
/span
/div
div class="form-row" style="border: none;"
span class="cell-6" style="text-align: left"
input type="reset" value="重置"
/span
span class="cell-6" style="text-align:right;"
input type="submit" value="注册"
/span
/div
/div !-- 注册表单结束 --
/form
/div
/body
/html
效果如下图：
在控制台接收到的图片中验证码的变化如下：
当点击刷新页面的时候，验证码也会随着变化，但我们看不清验证码时，只要点击验证码就会刷新，这样局部的刷新可以用JavaScript来实现。
在img
src="/demo/verify/regist.do"中，添加一个问号和一串后缀数字，当刷新时让后缀数字不断改变，那么形成的验证码也会不断变化，我们可以采用的一种办法是后缀数字用date代替，date获取本机时间，时间是随时变的，这样就保证了刷新验证码可以随时变化。
代码如下：
function myRefersh( e ) {
const source = e.src ; // 获得原来的 src 中的内容
//console.log( "source : " + source ) ;
var index = source.indexOf( "?" ) ; // 从 source 中寻找 ? 第一次出现的位置 (如果不存在则返回 -1 )
//console.log( "index : " + index ) ;
if( index -1 ) { // 如果找到了 ? 就进入内部
var s = source.substring( 0 , index ) ; // 从 source 中截取 index 之前的内容 ( index 以及 index 之后的内容都被舍弃 )
//console.log( "s : " + s ) ;
var date = new Date(); // 创建一个 Date 对象的 一个 实例
var time = date.getTime() ; // 从 新创建的 Date 对象的实例中获得该时间对应毫秒值
e.src = s + "?time=" + time ; // 将 加了 尾巴 的 地址 重新放入到 src 上
//console.log( e.src ) ;
} else {
var date = new Date();
e.src = source + "?time=" + date.getTime();
}
}
如回答不详细可追问
如何用Java代码段生成四位数字加字母的验证码？
不知道你问的是不是生成这种图片验证码？如果只要一个随机四位数 那这行代码就够了(new Random().nextInt(9000) + 1000;),如果是生成页面图片验证码就是下面的了: //设定 响应模式 resp.setContentType("image/jpeg"); // 生成令牌环数据; Integer token = new Random().nextInt(9000) + 1000; // 保存令牌环数据到session中 req.getSession().setAttribute(IMAGE_TOKEN_NAME, token); // 生成令牌环图片 ServletOutputStream out = resp.getOutputStream(); BufferedImage img = new BufferedImage(60, 20, BufferedImage.TYPE_INT_RGB); Graphics g = img.getGraphics(); g.setColor(Color.YELLOW); g.fillRect(0, 0, img.getWidth(), img.getHeight()); g.setColor(Color.BLUE); g.setFont(new Font("", Font.BOLD, 18)); g.drawString(String.valueOf(token), 10, 16); ImageIO.write(img, "jpg", out); out.close();
下面简单的介绍他们的功能和用途，执行效率等。每个都有各自的优缺点看你是做甚什么方面的研究开发用。.net，是网站编程，现在很多都用这个，但是这个语言编程都有统一思路，很好掌握。窒息那个效率不是很高；php 支持跨平台，很容易学会，执行的效率很高；asp是ASP.net的前身，它比较稳定，比.net要弱一点。但是比.net好学。jsp 是网页编程，这个学习大约一周就能搞定，不过这个得多实践，不然的话，时间长了，就容易忘记。
我自己做的系统里面用作验证码的JSP的%@page contentType="image/jpeg;charset=utf-8"%%@page import="java.util.*,java.awt.*,java.awt.image.*,javax.imageio.*" %%@ page import="java.io.OutputStream" %html body %! Color getRandColor(int fc,int bc) { Random rd=new Random(); if(fc255) fc=255; if(bc255) bc=255; int red=fc+rd.nextInt(bc-fc); int green=fc+rd.nextInt(bc-fc); int blue=fc+rd.nextInt(bc-fc); return new Color(red,green,blue); } % % Random r=new Random(); response.addHeader("Pragma","No-cache"); response.addHeader("Cache-Control","no-cache"); response.addDateHeader("expires",0); int width=90; int height=23; BufferedImage pic=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); Graphics gc=pic.getGraphics(); gc.setColor(getRandColor(200,250)); gc.fillRect(0,0,width,height); String[] rNum ={"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f", "g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w", "x","y","z","A","B","C","D","E","F","G","H","I","J","K","L","M","N", "O","P","Q","R","S","T","U","V","W","X","Y","Z"}; int[] style = {Font.PLAIN,Font.BOLD,Font.ITALIC,Font.PLAIN+Font.BOLD, Font.BOLD+Font.ITALIC,Font.PLAIN+Font.ITALIC,Font.PLAIN+Font.BOLD+Font.ITALIC}; gc.setColor(Color.WHITE); gc.drawLine(0,30,90,10); gc.setColor(getRandColor(160,200)); for (int i=0;i50;i++) { int x = r.nextInt(width); int y = r.nextInt(height); int xl = r.nextInt(10); int yl = r.nextInt(10); gc.drawLine(x,y,x+xl,y+yl); } gc.setColor(getRandColor(60,150)); String rt = ""; for(int i=0;i4;i++){ String temp = rNum[r.nextInt(62)]; rt = rt+temp; gc.setFont(new Font("Times New Roman",style[r.nextInt(7)],15)); gc.drawString(temp,5+i*15+r.nextInt(10),10+r.nextInt(10)); } gc.dispose(); session.setAttribute("randNum",rt); OutputStream os=response.getOutputStream(); ImageIO.write(pic,"JPEG",os); System.out.println("当前验证码为:"+session.getAttribute("randNum")); os.flush(); os.close(); os=null; response.flushBuffer(); out.clear(); out = pageContext.pushBody(); % /body/html
怎么用Java代码实现一个验证码，求具体实现方法
package util;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
public final class ImageUtil {
// 验证码字符集
private static final char[] chars = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
// 字符数量
private static final int SIZE = 4;
// 干扰线数量
private static final int LINES = 5;
// 宽度
private static final int WIDTH = 80;
// 高度
private static final int HEIGHT = 40;
// 字体大小
private static final int FONT_SIZE = 30;
/**
* 生成随机验证码及图片
* 返回的数组中，第1个值是验证码，第2个值是图片
*/
public static Object[] createImage() {
StringBuffer sb = new StringBuffer();
// 1.创建空白图片
BufferedImage image = new BufferedImage(
WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
// 2.获取图片画笔
Graphics graphic = image.getGraphics();
// 3.设置画笔颜色
graphic.setColor(Color.LIGHT_GRAY);
// 4.绘制矩形背景
graphic.fillRect(0, 0, WIDTH, HEIGHT);
// 5.画随机字符
Random ran = new Random();
for (int i = 0; i SIZE; i++) {
// 取随机字符索引
int n = ran.nextInt(chars.length);
// 设置随机颜色
graphic.setColor(getRandomColor());
// 设置字体大小
graphic.setFont(new Font(
null, Font.BOLD + Font.ITALIC, FONT_SIZE));
// 画字符
graphic.drawString(
chars[n] + "", i * WIDTH / SIZE, HEIGHT / 2);
// 记录字符
sb.append(chars[n]);
}
// 6.画干扰线
for (int i = 0; i LINES; i++) {
// 设置随机颜色
graphic.setColor(getRandomColor());
// 随机画线
graphic.drawLine(ran.nextInt(WIDTH), ran.nextInt(HEIGHT),
ran.nextInt(WIDTH), ran.nextInt(HEIGHT));
}
// 7.返回验证码和图片
return new Object[]{sb.toString(), image};
}
/**
* 随机取色
*/
public static Color getRandomColor() {
Random ran = new Random();
Color color = new Color(ran.nextInt(256),
ran.nextInt(256), ran.nextInt(256));
return color;
}
public static void main(String[] args) throws IOException {
Object[] objs = createImage();
BufferedImage image = (BufferedImage) objs[1];
OutputStream os = new FileOutputStream("d:/1.png");
ImageIO.write(image, "jpeg", os);
os.close();
}
}
求一个Java语言编写的gif动态验证码 就是百度注册用户的那种
你好，
Servlet类：
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ImageServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("image/gif");//设置相应类型,告诉浏览器输出的内容为图片
response.setHeader("Pragma", "No-cache");//设置响应头信息，告诉浏览器不要缓存此内容
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expire", 0);
RandomValidateCode randomValidateCode = new RandomValidateCode();
try {
randomValidateCode.getRandcode(request, response);//输出图片方法
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
生成图片的类：
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class RandomValidateCode {
public static final String RANDOMCODEKEY = "RANDOMVALIDATECODEKEY";//放到session中的key
private Random random = new Random();
private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生的字符串
private int width = 80;//图片宽
private int height = 26;//图片高
private int lineSize = 25;//干扰线数量
private int stringNum = 4;//随机产生字符数量
/**
* 生成随机图片
*/
public void getRandcode(HttpServletRequest request,
HttpServletResponse response) {
HttpSession session = request.getSession();
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_BGR);
Graphics g = image.getGraphics();
g.fillRect(0, 0, width, height);
g.setFont(new Font("Times New Roman",Font.ROMAN_BASELINE,18));
g.setColor(getRandColor(180, 233));
//绘制干扰线
for(int i=0;i=lineSize;i++){
drowLine(g);
}
//绘制随机字符
String randomString = "";
for(int i=1;i=stringNum;i++){
randomString=drowString(g,randomString,i);
}
session.removeAttribute(RANDOMCODEKEY);
session.setAttribute(RANDOMCODEKEY, randomString);
g.dispose();
try {
ImageIO.write(image, "JPEG", response.getOutputStream());
} catch (Exception e) {
e.printStackTrace();
}
}
// ------------- private methods -------------
/*
* 获得字体
*/
private Font getFont(){
return new Font("Fixedsys",Font.CENTER_BASELINE,18);
}
/*
* 获得颜色
*/
private Color getRandColor(int fc,int bc){
if(fc 255)
fc = 255;
if(bc 255)
bc = 255;
int r = fc + random.nextInt(bc-fc-16);
int g = fc + random.nextInt(bc-fc-14);
int b = fc + random.nextInt(bc-fc-18);
return new Color(r,g,b);
}
/*
* 绘制字符串
*/
private String drowString(Graphics g,String randomString,int i){
g.setFont(getFont());
g.setColor(new Color(random.nextInt(101),random.nextInt(111),random.nextInt(121)));
String rand = String.valueOf(getRandomString(random.nextInt(randString.length())));
randomString +=rand;
g.translate(random.nextInt(3), random.nextInt(3));
g.drawString(rand, 13*i, 16);
return randomString;
}
/*
* 绘制干扰线
*/
private void drowLine(Graphics g){
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(13);
int yl = random.nextInt(15);
g.drawLine(x, y, x+xl, y+yl);
}
/*
* 获取随机的字符
*/
private String getRandomString(int num){
return String.valueOf(randString.charAt(num));
}
}
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发布于：2022-12-06，除非注明，否则均为原创文章，转载请注明出处。