package com.zdsoft.serverlet.test01;

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

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;

/**
* servletcontext的使用（建立的servlet檔案）
*/
@SuppressWarnings(“serial”)
@WebServlet(“/VisitServlet”)
public class VisitServlet extends HttpServlet {

/**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 */
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    //解決中文輸入輸出亂碼問題
    request.setCharacterEncoding("utf-8");
    response.setCharacterEncoding("utf-8");
    response.setContentType("text/html charset=utf-8");
 

頁面訪問次數的解決程式碼

    PrintWriter pw=response.getWriter();
    //獲得servlet物件
    ServletContext sc=this.getServletContext();
    //通過屬性名來獲取屬性值（累計數量）
    Integer i=(Integer)sc.getAttribute("numble");
    int a=1;//計數器
    if(i!=null){
        a=i+1;  
    }
    //給ServletContext物件設定共享屬性和屬性值（該屬性和對應的屬性值不會因為重新整理就消失，依然會存在並儲存資料）
    sc.setAttribute("numble", a);
    pw.print("<font color='red'>你是第"+a+"個訪問者</font>");
    pw.flush();//重新整理流
    pw.close();//關流（但是列印的資訊不會消失，下次使用前有開啟流）  
 

    String ss=sc.getContextPath();//返回/工程名


}

/**
 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 */
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    doGet(request,response);
}

}