网页计数器servlet实现代码

最新推荐文章于 2023-01-11 22:54:13 发布

原创最新推荐文章于 2023-01-11 22:54:13 发布 · 1.8k 阅读

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#servlet #import #properties #string #exception #null

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本文介绍了一个基于Java Servlet的网站访问计数器实现方法，该计数器能够记录并显示特定网页的访问次数，使用了文件存储来保存计数信息，并通过JPEG图片形式展示计数结果。

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package testcount;

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;
import java.awt.*;
import java.awt.image.*;
import javax.imageio.*;

public class TestCount extends HttpServlet {

private final int WIDTH = 100;
private final int HEIGHT = 30;
private final int LEN = 7;

public void service(HttpServletRequest request, HttpServletResponse response)
   throws IOException, ServletException {
  response.setContentType("image/jpeg;charset=GB2312");
  response.setHeader("pragma", "No-cache");
  response.setHeader("Cache-Control", "no-cache");
  response.setDateHeader("Expires", 0);

  ServletOutputStream sos = response.getOutputStream();
  BufferedImage bufImage = new BufferedImage(WIDTH, HEIGHT,
    BufferedImage.TYPE_3BYTE_BGR);
  Graphics g = bufImage.getGraphics();
  // g.fillRect(0,0,WIDTH,HEIGHT);
  g.setFont(new Font("宋体", Font.BOLD, 20));
  g.setColor(Color.red);
  String strInt = getNumber(request);
  String tmp = "0";
  if (strInt.length() > 7) {
   strInt = "9999999";
  } else {
   for (int i = 0; i < LEN - strInt.length(); i++) {
    tmp = tmp + "0";

   }
   strInt = tmp + strInt;
  }
  g.drawString(strInt, 6, 23);
  ImageIO.write(bufImage, "JPEG", sos);
  sos.close();

}
public String getNumber(HttpServletRequest request) {
  String webNote = request.getHeader("Referer");// 获取请求头当浏览器URL发出请求的连接地址而获取次数值
  if (webNote == null) {
   return "0";
  }
  Properties pro = new Properties();
  String values = null;
  try {

   pro.load(new FileInputStream(this.getServletContext().getRealPath(
     "/properties//WebVisitCode.txt")));
   // pro.load(new
   // FileInputStream(getServletContext().getRealPath("/")+"properties//WebVisitCode.txt"));
   values = pro.getProperty(webNote);
   if (values == null) {
    values = "0";
   }
   int webCount = Integer.parseInt(values) + 1;
   values = Integer.toString(webCount);
   pro.setProperty(webNote, values);
   pro.store(new FileOutputStream(this.getServletContext()
     .getRealPath("/")
     + "properties//WebVisitCode.txt"), "file outputstream");

  } catch (Exception e) {
   e.printStackTrace();
  }
  return values;
}
}