WEB專案-通過ServletContext物件來統計網站的訪問次數
阿新 • • 發佈:2019-01-10
package com.servlet; import java.io.IOException; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /* * 從ServletContext物件中獲取值,然後再存入值 */ @WebServlet("/CountServlet") public class CountServlet extends HttpServlet { private static final long serialVersionUID = 1L; public void init() throws ServletException { ServletContext context = this.getServletContext(); //向ServletContext物件中存入變數,初始值為0 //設定一個變數 context.setAttribute("count",0); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ServletContext context = this.getServletContext(); //從context中獲取count,並且自增加一 //取出變數 Integer count = (Integer) context.getAttribute("count"); //讓count自加1 count++; //覆蓋之前count的值 context.setAttribute("count", count); //將count的值顯示到頁面上 response.setContentType("text/html;charset=UTF-8"); response.getWriter().write("訪問次數:"+count); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }