jsp頁面上：
<META HTTP-EQUIV="pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache, must-revalidate">
<meta http-equiv="expires" content="0">
<img id="vials" src="createPicture" style="height: 30px; width: 100px;">
//createPicture是control中的方法
function createPicture() {
var bigimg = document.getElementById("vials");
var url = "createPicture?m="+new Date();//new Date();防止ie緩存
bigimg.url;< /p>
};
java類產生數字與英文的驗證碼
package com.chinasofti.ljzs.cigaretteauthenticityquery.util;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.p_w_picpath.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Random;
import javax.p_w_picpathio.ImageIO;
import javax.p_w_picpathio.stream.ImageOutputStream;
public class VerificationCodeUtil {
private ByteArrayInputStream p_w_picpath;// 圖像
private String str;// 驗證碼
private static final int WIDTH = 80;
private static final int HEIGHT = 20;
BufferedImage p_w_picpaths;
public BufferedImage getImages() {
return p_w_picpaths;
}
public void setImages(BufferedImage p_w_picpaths) {
this.p_w_picpaths = p_w_picpaths;
}
public static void main(String[] arg) {
VerificationCodeUtil vcu = VerificationCodeUtil.Instance();
System.err.println(vcu.getVerificationCodeValue());
}
public static VerificationCodeUtil Instance() {
return new VerificationCodeUtil();
}
private VerificationCodeUtil() {
p_w_picpaths = new BufferedImage(WIDTH, HEIGHT,
BufferedImage.TYPE_INT_RGB);
//int randomNum = new Random().nextInt(1);
//if (randomNum == 1) {
initLetterAndNumVerificationCode(p_w_picpaths);
//}
}
public void initLetterAndNumVerificationCode(BufferedImage p_w_picpath) {
Random random = new Random(); // 生成隨機類
Graphics g = initImage(p_w_picpath, random);
String[] letter = { "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" };
String sRand = "";
for (int i = 0; i < 4; i++) {
String tempRand = "";
if (random.nextBoolean()) {
tempRand = String.valueOf(random.nextInt(10));
} else {
tempRand = letter[random.nextInt(25)];
if (random.nextBoolean()) {// 隨機將該字母變成小寫
tempRand = tempRand.toLowerCase();
}
}
sRand += tempRand;
g.setColor(new Color(20 + random.nextInt(10), 20 + random
.nextInt(110), 20 + random.nextInt(110)));
g.drawString(tempRand, 13 * i + 6, 16);
}
this.setStr(sRand);/* 賦值驗證碼 */
g.dispose(); // 圖象生效
this.setImage(drawImage(p_w_picpath));
}
public Graphics initImage(BufferedImage p_w_picpath, Random random) {
Graphics g = p_w_picpath.getGraphics(); // 獲取圖形上下文
g.setColor(getRandColor(200, 250));// 設定背景色
g.fillRect(0, 0, WIDTH, HEIGHT);
g.setFont(new Font("Times New Roman", Font.PLAIN, 20));// 設定字體
g.setColor(getRandColor(160, 200)); // 隨機產生165條幹擾線，使圖象中的認證碼不易被其它程序探測到
for (int i = 0; i < 165; 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);
}
return g;
}
public ByteArrayInputStream drawImage(BufferedImage p_w_picpath) {
ByteArrayInputStream input = null;
ByteArrayOutputStream output = new ByteArrayOutputStream();
try {
ImageOutputStream p_w_picpathOut = ImageIO
.createImageOutputStream(output);
ImageIO.write(p_w_picpath, "JPEG", p_w_picpathOut);
p_w_picpathOut.close();
input = new ByteArrayInputStream(output.toByteArray());
} catch (Exception e) {
System.out.println("驗證碼圖片產生出現錯誤：" + e.toString());
}
return input;
}
/*
* 功能：給定範圍獲得隨機顏色
*/
private Color getRandColor(int fc, int bc) {
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);
}
/**
* 功能：獲取驗證碼的字符串值
*
* @return
*/
public String getVerificationCodeValue() {
return this.getStr();
}
/**
* 功能：取得驗證碼圖片
*
* @return
*/
public ByteArrayInputStream getImage() {
return this.p_w_picpath;
}
public String getStr() {
return str;
}
public void setStr(String str) {
this.str = str;
}
public void setImage(ByteArrayInputStream p_w_picpath) {
this.p_w_picpath = p_w_picpath;
}
}
control層中
ImageIO.write(vcu.getImages(), "jpeg",response().getOutputStream());