Java Web笔记：Servlet取得httpSession以及servletContext

取得Session

使用Servlet还可以取得session对象，通过HttpServletRequest接口即可完成。

使用的方法是：getSession()。

取得Session对象：

package com.zzh.Servlet;

import java.io.IOException;
import java.rmi.ServerException;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class SessionServlet extends HttpServlet {
	public void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServerException, IOException {
		HttpSession session = req.getSession();
		System.out.println("Session ID:" + session.getId());
		session.setAttribute("name", "lunatictwo");
		System.out.println("name属性内容:" + session.getAttribute("name"));
	}

	public void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServerException, IOException {
		doGet(req, resp);
	}
}

配置web.xml文件：

<servlet>
		<servlet-name>session</servlet-name>
		<servlet-class>com.zzh.Servlet.SessionServlet</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>session</servlet-name>
		<url-pattern>/SessionServlet</url-pattern>
	</servlet-mapping>

tomcat后台显示：

取得ServletContext

package org.lxh.servletdemo ;
import java.io.* ;
import javax.servlet.* ;
import javax.servlet.http.* ;
public class ServletContextDemoServlet extends HttpServlet {
	public void doGet(HttpServletRequest req,HttpServletResponse resp) throws ServletException,IOException{
		ServletContext app = super.getServletContext() ;
		System.out.println("真实路径：" + app.getRealPath("/")) ;
	}
	public void doPost(HttpServletRequest req,HttpServletResponse resp) throws ServletException,IOException{
		this.doGet(req,resp) ;
	}
}

配置web.xml

<pre name="code" class="html"><span style="white-space:pre">	</span><servlet>
		<servlet-name>applicationdemo</servlet-name>
		<servlet-class>
			com.zzh.Servlet.ServletContextDemoServlet
		</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>applicationdemo</servlet-name>
		<url-pattern>/ServletContextDemoServlet</url-pattern>
	</servlet-mapping>