//web中 <init-param> <param-name>listings</param-name> <param-value>true</param-value> </init-param>
public void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { //1.获取servletconfig对象 // 表示servlet的配置信息 servletconfig config = this.getservletconfig(); //2.使用config读取初始化参数 string value = config.getinitparameter("listings"); system.out.println(value); //获取servletname system.out.println(config.getservletname()); } }
/*@override public void init(servletconfig config) throws servletexception { string value = config.getinitparameter("listings"); system.out.println(value); }*/
//web中 <context-param> <param-name>aaa</param-name> <param-value>bbb</param-value> </context-param>
public void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { //1.获取servletcontext:servlet的全局对象,整个项目就一个servletcontext对象 servletcontext sc1 = this.getservletcontext(); servletcontext sc2 = request.getservletcontext(); servletcontext sc3 = this.getservletconfig().getservletcontext(); //2.使用该对象 //读取全局配置信息 string val = sc1.getinitparameter("aaa"); system.out.println(val); //* 获取上下文路径 string contextpath = sc1.getcontextpath(); system.out.println(contextpath); //* 获取文件的绝对路径:从webroot下开始定位文件 string realpath = sc1.getrealpath("/image/1.jpg"); system.out.println(realpath); //获取资源,将资源作为流返回 inputstream in = sc1.getresourceasstream("/web-inf/car.properties"); //显示目录下的资源 set<string> paths = sc1.getresourcepaths("/aaa"); for (string string : paths) { system.out.println(string); } }
public void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { //1.request对象 request.setattribute("name", "zhangsan"); //request.getrequestdispatcher("scope2").forward(request, response); //2.session对象 先向浏览器输入,在用下面输出 httpsession session = request.getsession(); session.setattribute("age", 18); //3.application对象 先向浏览器输入,所有浏览器都可以输出 servletcontext sc = request.getservletcontext(); sc.setattribute("gender", "男"); }
public void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { //1.获取request对象中数据 /*string name = (string) request.getattribute("name"); system.out.println(name); //2.获取session对象中的数据 int age = (int) request.getsession().getattribute("age"); system.out.println(age);*/ //3.获取application对象中的数据 string gender = (string) request.getservletcontext().getattribute("gender"); system.out.println(gender); }
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