原理:
創(chuàng)新互聯(lián)是一家朝氣蓬勃的網(wǎng)站建設公司。公司專注于為企業(yè)提供信息化建設解決方案。從事網(wǎng)站開發(fā)，網(wǎng)站制作，網(wǎng)站設計，網(wǎng)站模板，微信公眾號開發(fā)，軟件開發(fā)，小程序開發(fā)，10余年建站對PE包裝袋等多個行業(yè)，擁有豐富的網(wǎng)站制作經(jīng)驗。
1.隨機生成4個數(shù)字 用到了Random類
2.對這4個數(shù)字設置字體格式 用 setFont方法
3.改變字體顏色用setColor 然后隨機生成顏色
代碼如下
package s1;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.jms.Session;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class GetImage extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 發(fā)送圖片不能夠添加這2行代碼
// response.setContentType("text/html;charset=UTF-8");
// request.setCharacterEncoding("UTF-8");
int width=100;
int height=50;
//獲得一張圖片
BufferedImage image=new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g=image.getGraphics();
g.setColor(Color.WHITE);
g.fillRect(1, 1, width-2, height-2);
g.setFont(new Font("宋體",Font.BOLD,30));
Random random=new Random();
// 填充的字符串
String str="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
//緩存生成的驗證碼
StringBuffer stringbuffer=new StringBuffer();
//隨機生成驗證碼的顏色和字符
for(int i=0;i4;i++)
{ //設置隨機顏色
g.setColor(new Color(random.nextInt(256), random.nextInt(256), random.nextInt(256)));
int index=random.nextInt(62);//這里的62就是從填充字符段中隨意選取一個位置
String str1=str.substring(index,index+1);
g.drawString(str1, 20*i, 30);//x,y數(shù)值設置太小會顯示不出來
stringbuffer.append(str1);
}
//將生成的驗證碼存到服務器
request.getSession().setAttribute("checkcode", stringbuffer.toString());//key和value
//將圖片發(fā)送給瀏覽器
ImageIO.write(image, "jpg", response.getOutputStream());
}
}
用戶登錄界面代碼
package s1;
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 javax.servlet.http.HttpSession;
public class Login extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");// 設置服務器發(fā)送給瀏覽器的編碼方式
request.setCharacterEncoding("UTF-8"); // 客戶端向服務器提交的數(shù)據(jù)的解碼方式
// 獲得用戶提交的數(shù)據(jù)
String checkcode = request.getParameter("checkcode");
System.out.println(checkcode);
// 判斷輸入的驗證碼是不是符合
HttpSession session = request.getSession();// session是存放數(shù)據(jù)的地方
String str = (String) session.getAttribute("checkcode");
if (str != null) {
if (checkcode.compareToIgnoreCase(str) == 0) // 驗證碼忽略大小寫
response.getWriter().println("驗證碼輸入正確");
else
response.getWriter().println("驗證碼輸入錯誤");
}
else response.getWriter().println("驗證碼失效");
// 使用完的驗證碼信息要刪除,返回原頁面再輸一次,驗證碼就失效了
session.removeAttribute("checkcode");
}
}
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?{
//?驗證碼字符集
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'};
//?字符數(shù)量
private?static?final?int?SIZE?=?4;
//?干擾線數(shù)量
private?static?final?int?LINES?=?5;
//?寬度
private?static?final?int?WIDTH?=?80;
//?高度
private?static?final?int?HEIGHT?=?40;
//?字體大小
private?static?final?int?FONT_SIZE?=?30;
/**
*?生成隨機驗證碼及圖片
*?返回的數(shù)組中，第1個值是驗證碼，第2個值是圖片
*/
public?static?Object[]?createImage()?{
StringBuffer?sb?=?new?StringBuffer();
//?1.創(chuàng)建空白圖片
BufferedImage?image?=?new?BufferedImage(
WIDTH,?HEIGHT,?BufferedImage.TYPE_INT_RGB);
//?2.獲取圖片畫筆
Graphics?graphic?=?image.getGraphics();
//?3.設置畫筆顏色
graphic.setColor(Color.LIGHT_GRAY);
//?4.繪制矩形背景
graphic.fillRect(0,?0,?WIDTH,?HEIGHT);
//?5.畫隨機字符
Random?ran?=?new?Random();
for?(int?i?=?0;?i?SIZE;?i++)?{
//?取隨機字符索引
int?n?=?ran.nextInt(chars.length);
//?設置隨機顏色
graphic.setColor(getRandomColor());
//?設置字體大小
graphic.setFont(new?Font(
null,?Font.BOLD?+?Font.ITALIC,?FONT_SIZE));
//?畫字符
graphic.drawString(
chars[n]?+?"",?i?*?WIDTH?/?SIZE,?HEIGHT?/?2);
//?記錄字符
sb.append(chars[n]);
}
//?6.畫干擾線
for?(int?i?=?0;?i??LINES;?i++)?{
//?設置隨機顏色
graphic.setColor(getRandomColor());
//?隨機畫線
graphic.drawLine(ran.nextInt(WIDTH),?ran.nextInt(HEIGHT),
ran.nextInt(WIDTH),?ran.nextInt(HEIGHT));
}
//?7.返回驗證碼和圖片
return?new?Object[]{sb.toString(),?image};
}
/**
*?隨機取色
*/
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();
}
}
不知道你問的是不是生成這種圖片驗證碼？如果只要一個隨機四位數(shù) 那這行代碼就夠了(new Random().nextInt(9000) + 1000;),如果是生成頁面圖片驗證碼就是下面的了: //設定 響應模式 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();
下面簡單的介紹他們的功能和用途，執(zhí)行效率等。每個都有各自的優(yōu)缺點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，但是這個語言編程都有統(tǒng)一思路，很好掌握。窒息那個效率不是很高；php 支持跨平臺，很容易學會，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。但是比.net好學。jsp 是網(wǎng)頁編程，這個學習大約一周就能搞定，不過這個得多實踐，不然的話，時間長了，就容易忘記。
我自己做的系統(tǒng)里面用作驗證碼的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("當前驗證碼為:"+session.getAttribute("randNum")); os.flush(); os.close(); os=null; response.flushBuffer(); out.clear(); out = pageContext.pushBody(); % /body/html
package com.bbs.servlet;
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();
// 生成隨機類
Random random = new Random();
// 設定背景色
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
// 設定字體
g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
// 隨機產(chǎn)生155條干擾線，使圖象中的認證碼不易被其它程序探測到
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);
}
// 取隨機產(chǎn)生的認證碼(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，可能是因為種子太接近，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對應0-9;65-90對應A-Z;97-122對應a-z;
String setRandValue(HttpServletRequest request) {
Random random = new Random();
String sRand = "";
//這里是生成驗證碼的位數(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;
}
}
這個首先你要確定一下短信平臺，他們會給你提供短信實現(xiàn)的接口文檔。
比如:
public static String doPost(String reqUrl, Map parameters, String recvEncoding)
{
HttpURLConnection url_con = null;
String responseContent = null;
try
{
StringBuffer params = new StringBuffer();
Iterator iter = parameters.entrySet().iterator();
while (iter
.hasNext())
{
Map.Entry element = (Map.Entry)iter.next();
params.append(element.getKey().toString());
params.append("=");
params.append(URLEncoder.encode(element.getValue().toString(),
requestEncoding));
params.append("");
}
if (params.length() 0)
{
params = params.deleteCharAt(params.length() - 1);
}
URL url = new URL(reqUrl);
url_con = (HttpURLConnection)url.openConnection();
url_con.setRequestMethod("POST");
System.setProperty("sun.net.client.defaultConnectTimeout",
String.valueOf(connectTimeOut));
System.setProperty("sun.net.client.defaultReadTimeout",
String.valueOf(readTimeOut));
url_con.setDoOutput(true);
byte[] b = params.toString().getBytes();
url_con.getOutputStream().write(b, 0, b.length);
url_con.getOutputStream().flush();
url_con.getOutputStream().close();
InputStream in = url_con.getInputStream();
BufferedReader rd = new BufferedReader(
new InputStreamReader(in,
recvEncoding));
String tempLine = rd.readLine();
StringBuffer tempStr = new StringBuffer();
String crlf = System.getProperty("line.separator");
while (tempLine != null)
{
tempStr.append(tempLine);
tempStr.append(crlf);
tempLine = rd.readLine();
}
responseContent = tempStr.toString();
rd.close();
in.close();
}
catch (IOException localIOException)
{
}
finally
{
if (url_con != null)
{
url_con.disconnect();
}
}
return responseContent;
}
public static String sendTelCode(String mobile,String telcode){
MapString ,String map = new HashMapString ,String();
map.put("account", "Babo");
map.put("mobile", mobile);
map.put("pswd", "D3dddD");
try {
map.put("msg", java.net.URLEncoder.encode("您的驗證碼是"+telcode+",若非本人操作請忽略","utf-8"));
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String getValue = doPost("", map, "UTF-8");
System.out.println(getValue);
return getValue;
}
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