一、使用DI注入的方式

DI注入的方式

controller

package com.controller.servletobj;import java.io.PrintWriter;import javax.servlet.ServletContext;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.servlet.ModelAndView;@Controllerpublic class ServletObj_1 {    @Autowired    private HttpServletRequest request;    @Autowired    private HttpServletResponse response;    @Autowired    private HttpSession session;    @Autowired    private ServletContext servletContext;    @RequestMapping(value = "/servletObj_1")    public ModelAndView exuecte() throws Exception {        response.setContentType("text/html");        String contextPath = request.getContextPath();        String sessionID = session.getId();        String indexPath = servletContext.getRealPath("/index.jsp");        PrintWriter out = response.getWriter();        out.println("contextPath = " + contextPath+"
");        out.println("sessionID = " + sessionID+"
");        out.println("indexPath = " + indexPath+"
");        out.flush();        out.close();        return null;    }}

 

二、形参传入的方式：ServletContext不能通过形参的方式注入，

形参传入的方式

controller

package com.controller.servletobj;import java.io.PrintWriter;import javax.servlet.ServletContext;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.servlet.ModelAndView;@Controllerpublic class ServletObj_2 {    @RequestMapping(value = "/servletObj_2")    public ModelAndView exuecte(HttpServletRequest request,            HttpServletResponse response, HttpSession session) throws Exception {        response.setContentType("text/html");        /**         * ServletContext不能通过形参的方式注入，         *          * 通过其他对象来进行获取。         */        ServletContext servletContext = request.getServletContext();        String contextPath = request.getContextPath();        String sessionID = session.getId();        String indexPath = servletContext.getRealPath("/index.jsp");        PrintWriter out = response.getWriter();        out.println("contextPath = " + contextPath + "
");        out.println("sessionID = " + sessionID + "
");        out.println("indexPath = " + indexPath + "
");        out.flush();        out.close();        return null;    }}

• ServletContext不能通过形参的方式注入，

 

三、拦截器的方式：只能注入ServletContextAware和ServletConfigAware接口

拦截器的方式

controller

package com.controller.servletobj;import java.io.PrintWriter;import javax.servlet.ServletConfig;import javax.servlet.ServletContext;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.context.ServletConfigAware;import org.springframework.web.context.ServletContextAware;import org.springframework.web.servlet.ModelAndView;/** * 通过拦截器来注入,只能注入ServletContextAware和ServletConfigAware接口 * */@Controllerpublic class ServletObj_3 implements ServletContextAware, ServletConfigAware {    private ServletContext servletContext;    private ServletConfig servletConfig;    @Override    public void setServletContext(ServletContext servletContext) {        this.servletContext = servletContext;    }    @Override    public void setServletConfig(ServletConfig servletConfig) {        this.servletConfig = servletConfig;    }    @RequestMapping(value = "/servletObj_3")    public ModelAndView exuecte(HttpServletRequest request,            HttpServletResponse response, HttpSession session) throws Exception {        response.setContentType("text/html");        String contextPath = request.getContextPath();        String sessionID = session.getId();        String indexPath = this.servletContext.getRealPath("/index.jsp");        PrintWriter out = response.getWriter();        out.println("contextPath = " + contextPath + "
");        out.println("sessionID = " + sessionID + "
");        out.println("indexPath = " + indexPath + "
");        out.flush();        out.close();        return null;    }}