randomimg.java

基于struts+hibernate的电子商务网站。可运行。数据库mysql

package tarena.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.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@SuppressWarnings("serial")
public class RandomIMG extends HttpServlet {

	private int width=50;//图像宽度
	private int height=20;//图像高度
	
	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void service(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("image/jpeg");
		ServletOutputStream sos=response.getOutputStream();
		
		Random r=new Random();
		
		//在内存中创建图像,宽度为width,高度为height
		BufferedImage pic=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
		//获取图形上下文环境
		Graphics gc=pic.getGraphics();
		
		//设定背景色并进行填充
		gc.setColor(getRandColor(200, 250));
		gc.fillRect(0, 0, width, height);
		
		//设置图形上下文环境字体
		gc.setFont(new Font("Times New Roman",Font.PLAIN,18));
		
		//随机产生200条干扰线条，使图像中的认证码不易被其他分析程序探测到
		gc.setColor(getRandColor(160, 200));
		for(int i=0;i<200;i++){
			int x1=r.nextInt(width);
			int y1=r.nextInt(height);
			int x2=r.nextInt(15);
			int y2=r.nextInt(15);
			gc.drawLine(x1, y1, x1+x2, y1+y2);
		}
		
		//随机产生100个干扰点，使图像中的验证码不易被其他分析程序探测到
		gc.setColor(getRandColor(120, 240));
		for(int i=0;i<100;i++){
			int x=r.nextInt(width);
			int y=r.nextInt(height);
			gc.drawOval(x, y, 0, 0);
		}
		
		//随机产生4个数字的验证码
		String rs="";
		String rn="";
		for(int i=0;i<4;i++){
			rn=String.valueOf(r.nextInt(10));
			rs+=rn;
			gc.setColor(new Color(20+r.nextInt(110),20+r.nextInt(110),20+r.nextInt(110)));
			gc.drawString(rn, 13*i+1, 16);
		}
		//释放图形上下文环境
		gc.dispose();
		
//		if(request.getSession().getAttribute("hk_verify")!=null || request.getSession().getAttribute("hk_verify")!=""){
//			request.getSession().setAttribute("hk_verify", null);
//			request.getSession().removeAttribute("hk_verify");
//		}
		//将认证码rs存放到session中共享
		request.getSession().setAttribute("seccode", rs);		
		
		//输出生成后的验证码图像到页面
		ImageIO.write(pic, "JPEG", sos);
		sos.flush();
		sos.close();
	}
	
	private Color getRandColor(int fc,int bc){
		Random r=new Random();
		if(fc>255) fc=255;
		if(bc>255) bc=255;
		int red=fc+r.nextInt(bc-fc);//红
		int green=fc+r.nextInt(bc-fc);//绿
		int blue=fc+r.nextInt(bc-fc);//蓝
		return new Color(red,green,blue);
	}

}