Session對象的創建和獲取 SessionServlet.java ~~~ package zyw.session; 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 javax.servlet.http.HttpSession; import java.io.IOException; @WebServlet(name = "SessionServlet",urlPatterns = "/session") public class SessionServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //第一次訪問時沒有session，服務器會自動創建一個session對象 //之后再次訪問的時候已經存在了session對象，這個直接獲取這個對象 HttpSession session=request.getSession(); String sessionId=session.getId(); response.getWriter().write("JESSIONID"+sessionId); } } ~~~