不知道你問(wèn)的是不是生成這種圖片驗(yàn)證碼?如果只要一個(gè)隨機(jī)四位數(shù) 那這行代碼就夠了(new Random().nextInt(9000) + 1000;),如果是生成頁(yè)面圖片驗(yàn)證碼就是下面的了: //設(shè)定 響應(yīng)模式 resp.setContentType("image/jpeg"); // 生成令牌環(huán)數(shù)據(jù); Integer token = new Random().nextInt(9000) + 1000; // 保存令牌環(huán)數(shù)據(jù)到session中 req.getSession().setAttribute(IMAGE_TOKEN_NAME, token); // 生成令牌環(huán)圖片 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();
網(wǎng)站制作、成都網(wǎng)站制作服務(wù)團(tuán)隊(duì)是一支充滿(mǎn)著熱情的團(tuán)隊(duì),執(zhí)著、敏銳、追求更好,是創(chuàng)新互聯(lián)的標(biāo)準(zhǔn)與要求,同時(shí)竭誠(chéng)為客戶(hù)提供服務(wù)是我們的理念。創(chuàng)新互聯(lián)把每個(gè)網(wǎng)站當(dāng)做一個(gè)產(chǎn)品來(lái)開(kāi)發(fā),精雕細(xì)琢,追求一名工匠心中的細(xì)致,我們更用心!
下面簡(jiǎn)單的介紹他們的功能和用途,執(zhí)行效率等。每個(gè)都有各自的優(yōu)缺點(diǎn)看你是做甚什么方面的研究開(kāi)發(fā)用。.net,是網(wǎng)站編程,現(xiàn)在很多都用這個(gè),但是這個(gè)語(yǔ)言編程都有統(tǒng)一思路,很好掌握。窒息那個(gè)效率不是很高;php 支持跨平臺(tái),很容易學(xué)會(huì),執(zhí)行的效率很高;asp是ASP.net的前身,它比較穩(wěn)定,比.net要弱一點(diǎn)。但是比.net好學(xué)。jsp 是網(wǎng)頁(yè)編程,這個(gè)學(xué)習(xí)大約一周就能搞定,不過(guò)這個(gè)得多實(shí)踐,不然的話(huà),時(shí)間長(zhǎng)了,就容易忘記。
我自己做的系統(tǒng)里面用作驗(yàn)證碼的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("當(dāng)前驗(yàn)證碼為:"+session.getAttribute("randNum")); os.flush(); os.close(); os=null; response.flushBuffer(); out.clear(); out = pageContext.pushBody(); % /body/html
Java如何實(shí)現(xiàn)驗(yàn)證碼驗(yàn)證功能呢?日常生活中,驗(yàn)證碼隨處可見(jiàn),他可以在一定程度上保護(hù)賬號(hào)安全,那么他是怎么實(shí)現(xiàn)的呢?
Java實(shí)現(xiàn)驗(yàn)證碼驗(yàn)證功能其實(shí)非常簡(jiǎn)單:用到了一個(gè)Graphics類(lèi)在畫(huà)板上繪制字母,隨機(jī)選取一定數(shù)量的字母隨機(jī)生成,然后在畫(huà)板上隨機(jī)生成幾條干擾線。
首先,寫(xiě)一個(gè)驗(yàn)證碼生成幫助類(lèi),用來(lái)繪制隨機(jī)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驗(yàn)證碼,同時(shí)輸出一個(gè)圖片
*
*?@param?width
*????????????圖片的寬度
*?@param?height
*????????????圖片的高度
*?@param?imgType
*????????????圖片的類(lèi)型
*?@param?output
*????????????圖片的輸出流(圖片將輸出到這個(gè)流中)
*?@return?返回所生成的驗(yàn)證碼(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?"畫(huà)板"上生成干擾線條?(?50?是線條個(gè)數(shù))
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?"畫(huà)板"上繪制字母
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();
}
}?
接著,創(chuàng)建一個(gè)servlet,用來(lái)固定圖片大小,以及處理驗(yàn)證碼的使用場(chǎng)景,以及捕獲頁(yè)面生成的驗(yàn)證碼(捕獲到的二維碼與用戶(hù)輸入的驗(yàn)證碼一致才能通過(guò))。
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?{
//?獲得?當(dāng)前請(qǐng)求?對(duì)應(yīng)的?會(huì)話(huà)對(duì)象
HttpSession?session?=?request.getSession();
//?從請(qǐng)求中獲得?URI?(?統(tǒng)一資源標(biāo)識(shí)符?)
String?uri?=?request.getRequestURI();
System.out.println("hello?:?"?+?uri);
final?int?width?=?180;?//?圖片寬度
final?int?height?=?40;?//?圖片高度
final?String?imgType?=?"jpeg";?//?指定圖片格式?(不是指MIME類(lèi)型)
final?OutputStream?output?=?response.getOutputStream();?//?獲得可以向客戶(hù)端返回圖片的輸出流
//?(字節(jié)流)
//?創(chuàng)建驗(yàn)證碼圖片并返回圖片上的字符串
String?code?=?GraphicHelper.create(width,?height,?imgType,?output);
System.out.println("驗(yàn)證碼內(nèi)容:?"?+?code);
//?建立?uri?和?相應(yīng)的?驗(yàn)證碼?的關(guān)聯(lián)?(?存儲(chǔ)到當(dāng)前會(huì)話(huà)對(duì)象的屬性中?)
session.setAttribute(uri,?code);
System.out.println(session.getAttribute(uri));
}
}?
接著寫(xiě)一個(gè)HTML注冊(cè)頁(yè)面用來(lái)檢驗(yàn)一下:
html
head
meta?charset="UTF-8"
title注冊(cè)/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"?!--?注冊(cè)表單開(kāi)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="請(qǐng)輸入用戶(hù)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="請(qǐng)輸入密碼"
/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="請(qǐng)確認(rèn)密碼"
/span
/div
div?class="form-row"
span?class="cell-7"
input?type="text"?name="verifyCode"?placeholder="請(qǐng)輸入驗(yàn)證碼"
/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="注冊(cè)"
/span
/div
/div?!--?注冊(cè)表單結(jié)束?--
/form
/div
/body
/html
效果如下圖:
在控制臺(tái)接收到的圖片中驗(yàn)證碼的變化如下:
當(dāng)點(diǎn)擊刷新頁(yè)面的時(shí)候,驗(yàn)證碼也會(huì)隨著變化,但我們看不清驗(yàn)證碼時(shí),只要點(diǎn)擊驗(yàn)證碼就會(huì)刷新,這樣局部的刷新可以用JavaScript來(lái)實(shí)現(xiàn)。
在img
src="/demo/verify/regist.do"中,添加一個(gè)問(wèn)號(hào)和一串后綴數(shù)字,當(dāng)刷新時(shí)讓后綴數(shù)字不斷改變,那么形成的驗(yàn)證碼也會(huì)不斷變化,我們可以采用的一種辦法是后綴數(shù)字用date代替,date獲取本機(jī)時(shí)間,時(shí)間是隨時(shí)變的,這樣就保證了刷新驗(yàn)證碼可以隨時(shí)變化。
代碼如下:
function?myRefersh(?e?)?{
const?source?=?e.src?;?//?獲得原來(lái)的?src?中的內(nèi)容
//console.log(?"source?:?"?+?source??)?;
var?index?=?source.indexOf(?"?"?)?;??//?從?source?中尋找???第一次出現(xiàn)的位置?(如果不存在則返回?-1?)
//console.log(?"index?:?"?+?index??)?;
if(?index??-1?)?{?//?如果找到了????就進(jìn)入內(nèi)部
var?s?=?source.substring(?0?,?index?)?;?//?從?source?中截取?index?之前的內(nèi)容?(?index?以及?index?之后的內(nèi)容都被舍棄?)
//console.log(?"s?:?"?+?s??)?;
var?date?=?new?Date();?//?創(chuàng)建一個(gè)?Date?對(duì)象的?一個(gè)?實(shí)例
var?time?=?date.getTime()?;?//?從?新創(chuàng)建的?Date?對(duì)象的實(shí)例中獲得該時(shí)間對(duì)應(yīng)毫秒值
e.src?=?s?+?"?time="?+?time?;?//?將?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();
}
}
如回答不詳細(xì)可追問(wèn)
現(xiàn)在許多系統(tǒng)的注冊(cè) 登錄或者發(fā)布信息模塊都添加的隨機(jī)驗(yàn)證碼功能 就是為了避免自動(dòng)注冊(cè)程序或者自動(dòng)發(fā)布程序的使用
驗(yàn)證碼實(shí)際上就是隨機(jī)選擇一些字符以圖片的形式展現(xiàn)在頁(yè)面上 如果進(jìn)行提交操作的同時(shí)需要將圖片上的字符同時(shí)提交 如果提交的字符與服務(wù)器session保存的不同 則認(rèn)為提交信息無(wú)效 為了避免自動(dòng)程序分析解析圖片 通常會(huì)在圖片上隨機(jī)生成一些干擾線或者將字符進(jìn)行扭曲 增加自動(dòng)識(shí)別驗(yàn)證碼的難度
在這里 我們使用java實(shí)現(xiàn)驗(yàn)證碼
%@ page contentType= image/jpeg import= java awt * java awt image * java util * javax imageio * %
%!
Color getRandColor(int fc int bc){//給定范圍獲得隨機(jī)顏色
Random random = new Random();
if(fc ) fc= ;
if(bc ) bc= ;
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);
}
%
%
//設(shè)置頁(yè)面不緩存
response setHeader( Pragma No cache );
response setHeader( Cache Control no cache );
response setDateHeader( Expires );
// 在內(nèi)存中創(chuàng)建圖象
int width= height= ;
BufferedImage image = new BufferedImage(width height BufferedImage TYPE_INT_RGB);
// 獲取圖形上下文
Graphics g = image getGraphics();
//生成隨機(jī)類(lèi)
Random random = new Random();
// 設(shè)定背景色
g setColor(getRandColor( ));
g fillRect( width height);
//設(shè)定字體
g setFont(new Font( Times New Roman Font PLAIN ));
// 隨機(jī)產(chǎn)生 條干擾線 使圖象中的認(rèn)證碼不易被其它程序探測(cè)到
g setColor(getRandColor( ));
for (int i= ;i ;i++)
{
int x = random nextInt(width);
int y = random nextInt(height);
int xl = random nextInt( );
int yl = random nextInt( );
g drawLine(x y x+xl y+yl);
}
// 取隨機(jī)產(chǎn)生的認(rèn)證碼( 位數(shù)字)
String codeList = ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz ;
String sRand= ;
for (int i= ;i ;i++){
int a=random nextInt(codeList length() );
String rand=codeList substring(a a+ );
sRand+=rand;
// 將認(rèn)證碼顯示到圖象中
g setColor(new Color( +random nextInt( ) +random nextInt( ) +random nextInt( )));//調(diào)用函數(shù)出來(lái)的顏色相同 可能是因?yàn)榉N子太接近 所以只能直接生成
g drawString(rand *i+ );
}
// 將認(rèn)證碼存入SESSION
session setAttribute( rand sRand);
// 圖象生效
g dispose();
// 輸出圖象到頁(yè)面
ImageIO write(image JPEG response getOutputStream());
out clear();
out = pageContext pushBody();
lishixinzhi/Article/program/Java/hx/201311/25536
本文標(biāo)題:java輸入驗(yàn)證碼代碼 java編寫(xiě)驗(yàn)證碼登錄頁(yè)面
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