com.it.demo.VisitServlet

package com.it.demo;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 用於統計站點訪問次數
 * @author xie
 *
 */
public class VisitServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//1.獲取ServletContext物件
		ServletContext context = this.getServletContext();
		//2.直接取出訪問次數
		Integer count = (Integer) context.getAttribute("count");
		//3.判斷count是否為null，如果為null，則說明是第一次訪問
		if(count == null) {
			count = 1;
		}else {
			count += 1;
		}
		//4.將count重新儲存
		context.setAttribute("count", count);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}

}
 

com.it.demo.ShowServlet

package com.it.demo;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 用於顯示站點訪問次數
 * @author xie
 *
 */
public class ShowServlet extends HttpServlet {


	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("text/html;charset=utf-8");
		//1.得到ServletContext
		ServletContext context = this.getServletContext();
		//2.取出訪問次數
		Integer count = (Integer)context.getAttribute("count");
		//3.寫出到頁面
		response.getWriter().write("站點被訪問" + count + "次");
	}

	
	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}

}