javaweb简单二维码

来源：互联网发布：微商和淘宝哪个挣钱编辑：程序博客网时间：2024/05/20 03:07

webxml:

<servlet>
<servlet-name>AuthImageServlet</servlet-name>
<servlet-class>com.util.servlet.AuthImageServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AuthImageServlet</servlet-name>
<url-pattern>/servlet/AuthImageServlet</url-pattern>
</servlet-mapping>

JSP：

<body>

<form action="" method="post">
<label>输入验证码</label><br/>
<input type="text" name="randomCode"/><img id="vimg" title="点击更换" onclick="changeCode();" src="servlet/AuthImageServlet"><br/>

</form>
</body>

Servlet:

package com.util.servlet;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
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 javax.servlet.http.HttpSession;
public class AuthImageServlet extends HttpServlet {
private static final String CONTENT_TYPE = "text/html; charset=gb2312";
//设置字母的大小,大小
private Font mFont = new Font("Times New Roman", Font.PLAIN, 17);
public void init() throws ServletException
{
super.init();
}
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);
}

public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
//表明生成的响应是图片
response.setContentType("image/jpeg");

int width=100, height=18;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

Graphics g = image.getGraphics();
Random random = new Random();
g.setColor(getRandColor(200,250));
g.fillRect(1, 1, width-1, height-1);
g.setColor(new Color(102,102,102));
g.drawRect(0, 0, width-1, height-1);
g.setFont(mFont);

g.setColor(getRandColor(160,200));

//画随机线
for (int i=0;i<155;i++)
{
int x = random.nextInt(width - 1);
int y = random.nextInt(height - 1);
int xl = random.nextInt(6) + 1;
int yl = random.nextInt(12) + 1;
g.drawLine(x,y,x + xl,y + yl);
}

//从另一方向画随机线
for (int i = 0;i < 70;i++)
{
int x = random.nextInt(width - 1);
int y = random.nextInt(height - 1);
int xl = random.nextInt(12) + 1;
int yl = random.nextInt(6) + 1;
g.drawLine(x,y,x - xl,y - yl);
}

//生成随机数,并将随机数字转换为字母
String sRand="";
for (int i=0;i<6;i++)
{
int itmp = random.nextInt(26) + 65;
char ctmp = (char)itmp;
sRand += String.valueOf(ctmp);
g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
g.drawString(String.valueOf(ctmp),15*i+10,16);
}

HttpSession session = request.getSession(true);
session.setAttribute("rand",sRand); //注意转换为字母的二维码字母char存在Session中可调取用于判断输入框和二维码是否相等

g.dispose();
ImageIO.write(image, "JPEG", response.getOutputStream());
}

}

0 0