Servlet学习的两个案例之网站访问次数的统计

一、统计次数的Servlet源码

package com.shanrengo;



import java.io.IOException;



import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;



/**

 * 用戶訪問countServlet，訪問次數+1

 * 1.在countServlet初始化的時候，向ServletContext中保存一個訪問次數0

 * @author Administrator

 *

 */

public class CountServlet extends HttpServlet {



	@Override

	public void init() throws ServletException {

		// TODO Auto-generated method stub

		//向ServletContext保存訪問次數0

		//ServletContext 中setAttribute方法

		//1.獲得servletContext對象

		ServletContext context = getServletContext();

		//2.保存數據

		context.setAttribute("visitTimes", 0);

		

	}

	

	public void doGet(HttpServletRequest request, HttpServletResponse response)

			throws ServletException, IOException {

		//每次訪問都會執行doGet

		//1.從servletContext中獲得visitTimes

		ServletContext context = getServletContext();

		int times = (Integer) context.getAttribute("visitTimes");

		//2.將visitTimes++

		times++;

		//3.更新

		context.setAttribute("visitTimes", times);

		System.out.println("網站被訪問了一次！");

	}



	public void doPost(HttpServletRequest request, HttpServletResponse response)

			throws ServletException, IOException {

		doGet(request, response);

	}



}

 

二、显示统计次数的servlet源码

package com.shanrengo;



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;



public class CountShowServlet extends HttpServlet {





	public void doGet(HttpServletRequest request, HttpServletResponse response)

			throws ServletException, IOException {



		ServletContext context = getServletContext();

		int times = (Integer) context.getAttribute("visitTimes");

		

		response.getWriter().println(times);

	}





	public void doPost(HttpServletRequest request, HttpServletResponse response)

			throws ServletException, IOException {

		doGet(request, response);

	}



}

　　

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