~~~ package com.servlet; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; public class ServletDemo extends HttpServlet { //屬性賦值，在單例上會有線程安全問題 private Integer id=0; protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("haha"); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { id +=1; Integer num = 0; num+=1; System.out.println(id); System.out.println(num); /** * 1.獲得客戶機信息 */ String requestUrl = request.getRequestURL().toString();//得到請求的URL地址 String requestUri = request.getRequestURI();//得到請求的資源 String queryString = request.getQueryString();//得到請求的URL地址中附帶的參數 String remoteAddr = request.getRemoteAddr();//得到來訪者的IP地址 String remoteHost = request.getRemoteHost(); int remotePort = request.getRemotePort(); String remoteUser = request.getRemoteUser(); String method = request.getMethod();//得到請求URL地址時使用的方法 String pathInfo = request.getPathInfo(); String localAddr = request.getLocalAddr();//獲取WEB服務器的IP地址 String localName = request.getLocalName();//獲取WEB服務器的主機名 response.setCharacterEncoding("UTF-8");//設置將字符以"UTF-8"編碼輸出到客戶端瀏覽器 //通過設置響應頭控制瀏覽器以UTF-8的編碼顯示數據，如果不加這句話，那么瀏覽器顯示的將是亂碼 response.setHeader("content-type", "text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); out.write("獲取到的客戶機信息如下："); out.write("<hr/>"); out.write("請求的URL地址："+requestUrl); out.write("<br/>"); out.write("請求的資源："+requestUri); out.write("<br/>"); out.write("請求的URL地址中附帶的參數："+queryString); out.write("<br/>"); out.write("來訪者的IP地址："+remoteAddr); out.write("<br/>"); out.write("來訪者的主機名："+remoteHost); out.write("<br/>"); out.write("使用的端口號："+remotePort); out.write("<br/>"); out.write("remoteUser："+remoteUser); out.write("<br/>"); out.write("請求使用的方法："+method); out.write("<br/>"); out.write("pathInfo："+pathInfo); out.write("<br/>"); out.write("localAddr："+localAddr); out.write("<br/>"); out.write("localName："+localName); } } ~~~ 注：在單例的類上，不用屬性作用域，轉用局部方法作用域