驗(yàn)證碼部分的java代碼怎么寫

package com.bbs.servlet;

創(chuàng)新互聯(lián)-專業(yè)網(wǎng)站定制、快速模板網(wǎng)站建設(shè)、高性價(jià)比崇州網(wǎng)站開發(fā)、企業(yè)建站全套包干低至880元,成熟完善的模板庫(kù),直接使用。一站式崇州網(wǎng)站制作公司更省心,省錢,快速模板網(wǎng)站建設(shè)找我們，業(yè)務(wù)覆蓋崇州地區(qū)。費(fèi)用合理售后完善，十多年實(shí)體公司更值得信賴。

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.io.PrintWriter;

import java.util.Random;

import javax.imageio.ImageIO;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.sun.image.codec.jpeg.JPEGCodec;

import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class Image extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("image/jpeg");

OutputStream out = response.getOutputStream();

response.setHeader("Pragma","No-cache");

response.setHeader("Cache-Control","no-cache");

response.setDateHeader("Expires", 0);

int width = 60, height = 20;

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

Random random = new Random();

// 設(shè)定背景色

g.setColor(getRandColor(200, 250));

g.fillRect(0, 0, width, height);

// 設(shè)定字體

g.setFont(new Font("Times New Roman", Font.PLAIN, 18));

// 隨機(jī)產(chǎn)生155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(180, 200));

for (int i = 0; i 155; 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);

}

// 取隨機(jī)產(chǎn)生的認(rèn)證碼(4位數(shù)字)

String sRand =setRandValue(request);

if(sRand!=null)

for (int i = 0; i sRand.length(); i++) {

g.setColor(new Color(20 + random.nextInt(200), 20 + random

.nextInt(200), 20 + random.nextInt(200)));

// 調(diào)用函數(shù)出來的顏色相同，可能是因?yàn)榉N子太接近，所以只能直接生成

g.drawString(sRand.charAt(i) + "", 13 * i + 6, 16);

}

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

encoder.encode(image);

// 圖象生效

g.dispose();

// 輸出圖象到頁(yè)面

// ImageIO.write(image, "JPG", response.getOutputStream());

out.flush();

out.close();

}

Color getRandColor(int fc, int bc) {// 給定范圍獲得隨機(jī)顏色

Random random = new Random();

if (fc 255)

fc = 255;

if (bc 255)

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);

}

//48-57對(duì)應(yīng)0-9;65-90對(duì)應(yīng)A-Z;97-122對(duì)應(yīng)a-z;

String setRandValue(HttpServletRequest request) {

Random random = new Random();

String sRand = "";

//這里是生成驗(yàn)證碼的位數(shù)

for (int i = 0; i 4; i++) {

char c = 0;

int k = random.nextInt(3);

switch (k) {

case 0:

c = (char) (random.nextInt(10) + 48);

break;

case 1:

c = (char) (random.nextInt(26) + 65);

break;

case 2:

c = (char) (random.nextInt(26) + 97);

}

sRand += c;

}

request.getSession().setAttribute("rands", sRand);

return sRand;

}

}

如何用Java代碼段生成四位數(shù)字加字母的驗(yàn)證碼？

不知道你問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();

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，不過這個(gè)得多實(shí)踐，不然的話，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

怎樣用java實(shí)現(xiàn)驗(yàn)證碼

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

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

當(dāng)前標(biāo)題：java中驗(yàn)證碼源代碼 java編寫驗(yàn)證碼
分享網(wǎng)址：http://chinadenli.net/article48/dojiiep.html

成都網(wǎng)站建設(shè)公司_創(chuàng)新互聯(lián)，為您提供用戶體驗(yàn)、外貿(mào)網(wǎng)站建設(shè)、網(wǎng)站營(yíng)銷、全網(wǎng)營(yíng)銷推廣、軟件開發(fā)、企業(yè)網(wǎng)站制作

廣告

聲明：本網(wǎng)站發(fā)布的內(nèi)容（圖片、視頻和文字）以用戶投稿、用戶轉(zhuǎn)載內(nèi)容為主，如果涉及侵權(quán)請(qǐng)盡快告知，我們將會(huì)在第一時(shí)間刪除。文章觀點(diǎn)不代表本網(wǎng)站立場(chǎng)，如需處理請(qǐng)聯(lián)系客服。電話：028-86922220；郵箱：631063699@qq.com。內(nèi)容未經(jīng)允許不得轉(zhuǎn)載，或轉(zhuǎn)載時(shí)需注明來源： 創(chuàng)新互聯(lián)