/*******************************sping mvc controller***********************************/
//獲取驗證碼
@Path("identifying")
@GET
public void getIdentifying(@Context HttpServletRequest request,@Context HttpServletResponse response){
response.setContentType("image/jpeg");//設定相應型別,告訴瀏覽器輸出的內容為圖片
response.setHeader("Pragma", "No-cache");//設定響應頭資訊，告訴瀏覽器不要快取此內容
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expire", 0);
RandomValidateCode randomValidateCode = new RandomValidateCode();
try {
randomValidateCode.getRandcode(request, response);//輸出圖片方法
} catch (Exception e) {
e.printStackTrace();
}
}
/*******************************util返回動態驗證碼圖片***********************************/
package com.netutel.web.util;
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 = "rand";// 放到session中的key
private Random random = new Random();
private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";// 隨機產生的字串
private int width = 80;// 圖片寬
private int height = 26;// 圖片高
private int lineSize = 40;// 干擾線數量
private int stringNum = 4;// 隨機產生字元數量
/*
* 獲得字型
*/
private Font getFont() {
return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
}
/*
* 獲得顏色
*/
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);
}
/**
* 生成隨機圖片
*/
public void getRandcode(HttpServletRequest request,
HttpServletResponse response) {
HttpSession session = request.getSession();
// BufferedImage類是具有緩衝區的Image類,Image類是用於描述影像資訊的類
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_BGR);
Graphics g = image.getGraphics();// 產生Image物件的Graphics物件,改物件可以在影像上進行各種繪製操作
g.fillRect(0, 0, width, height);
g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
g.setColor(getRandColor(110, 133));
// 繪製干擾線
for (int i = 0; i <= lineSize; i++) {
drowLine(g);
}
// 繪製隨機字元
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());// 將記憶體中的圖片通過流動形式輸出到客戶端
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* 繪製字串
*/
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;
}
/*
* 繪製干擾線
*/
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);
}
/*
* 獲取隨機的字元
*/
public String getRandomString(int num) {
return String.valueOf(randString.charAt(num));
}
}
/*******************************jsp發起呼叫***********************************/
<li><img title="點選更換" onclick="javascript:refresh(this);" src="ws/user/identifying"></li>
/*******************************js***********************************/
function refresh(obj) {
obj.src = "ws/user/identifying?"+Math.random();
}