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package org.lsf.action;
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.HttpServletResponse;
import org.apache.struts2.ServletActionContext;
public class CheckAction {
public String exec() throws Exception {
HttpServletResponse response = ServletActionContext.getResponse();
int codeLength = 4;// 验证码长度
int mixTimes = 1;// 模糊程度参数
Color bgColor = getRandColor(200, 250);// 背景颜色
Color bfColor = new Color(0, 0, 0);// 字体颜色
boolean ifRandomColor = true;// 单个字符是否颜色随机
boolean ifMixColor = false;// 模糊线是否颜色随机
// 设置页面不缓存
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
// 在内存中创建图象
int width = 13 * codeLength + 6, height = 20;
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
// 获取图形上下文
Graphics g = image.getGraphics();
// 设定背景色
g.setColor(bgColor);
g.fillRect(0, 0, width, height);
// 设定字体
g.setFont(new Font("Arail", Font.BOLD, 18));
// 画边框
g.setColor(new Color(33, 66, 99));
g.drawRect(0, 0, width - 1, height - 1);
// 随机产生干扰线,使图象中的认证码不易被其它程序探测到
g.setColor(getRandColor(160, 200));
for (int i = 0; i < mixTimes * codeLength / 10; i++) {
if (ifMixColor) {
g.setColor(getRandColor(160, 200));
}
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);
}
// 取随机产生的认证码(4位数字)
// 向图片中输出数字和字母
Random r=new Random();
StringBuffer sb = new StringBuffer();
char[] ch = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();
int index, len = ch.length;
String sRand = "";
for (int i = 0; i < codeLength; i ++) {
index = r.nextInt(len);
String rand =String.valueOf(ch[index]);
sRand += rand;
// 将认证码显示到图象中
if (ifRandomColor)
g.setColor(getRandColor(20, 110, 0));
else
g.setColor(bfColor);
// 调用函数出来的颜色相同,可能是因为种子太接近,所以只能直接生成
g.drawString(rand, 13 * i + 6, 16);
}
// 将认证码存入SESSION
// 图象生效
ServletActionContext.getRequest().getSession().setAttribute("rand",
sRand);
g.dispose();
// 输出图象到页面
ImageIO.write(image, "PNG", response.getOutputStream());
return "success";
}
private static Random random = new Random();
private Color getRandColor(int fc, int bc) {
return getRandColor(fc, bc, fc);
}
private Color getRandColor(int fc, int bc, int interval) {
if (fc > 255) {
fc = 255;
}
if (bc > 255) {
bc = 255;
}
int r = fc + random.nextInt(bc - interval);
int g = fc + random.nextInt(bc - interval);
int b = fc + random.nextInt(bc - interval);
return new Color(r, g, b);
}
}
//jsp页面代码
<INPUT id="yanzhen" class=regtxt style="width:60px;" title=请输入验证码 maxLength=5 size=16
name="yanzhen" > <a href="javascript:reloadVerifyCode()"><img src="<%=request.getContextPath()%>/checks_exec" id="safecode" /></a>
//点击换图片js代码
function reloadVerifyCode(){
var timenow = new Date().getTime();
document.getElementById("safecode").src="<%=request.getContextPath()%>/checks_exec?d="+timenow;
}
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