未从jsp中的pageContext对象获取属性
未从jsp中的pageContext对象获取属性
提问于 2017-07-19 15:00:40
我没有从jsp代码中的pageContext对象获取属性：
<%
String username =request.getParameter("name");
if(username!=null){
//session.setAttribute("sessionUsername", username);
//application.setAttribute("appUsername", username);
pageContext.setAttribute( "requestParams",username );
pageContext.setAttribute("requestScope", username, PageContext.REQUEST_SCOPE);
pageContext.setAttribute("sessionScope", username, PageContext.SESSION_SCOPE);
pageContext.setAttribute("applicationScope", username, PageContext.APPLICATION_SCOPE);
}
/* String sessionName =(String)session.getAttribute("sessionUsername");
String applicaString = (String)application.getAttribute("appUsername");
*/
%>
<%-- <br>
the name is : <%=username%>
<br>
the session name is : <%=sessionName%>
<br>
the application name is : <%=applicaString%>
--%>
<br>
the request Scope name is : <%=pageContext.getAttribute("requestScope")%>
<br>
the sessionScope name is : <%=pageContext.getAttribute("sessionScope")%>
<br>
the appication Scope name is : <%=pageContext.getAttribute("applicationScope")%>
<br>
the page Scope name is : <%=pageContext.getAttribute("requestParams")%>我在应用程序作用域和请求作用域中得到了null，但是当我使用具有默认页面作用域的setAttribute方法时，它工作得很好。
回答 1
Stack Overflow用户
发布于 2017-07-19 22:44:50
尝试将您的代码更改为：
<%
String username =request.getParameter("name");
if(username!=null){
//session.setAttribute("sessionUsername", username);
//application.setAttribute("appUsername", username);
pageContext.setAttribute( "requestParams",username );
pageContext.setAttribute("requestScope", username, PageContext.REQUEST_SCOPE);
pageContext.setAttribute("sessionScope", username, PageContext.SESSION_SCOPE);
pageContext.setAttribute("applicationScope", username, PageContext.APPLICATION_SCOPE);
}
/* String sessionName =(String)session.getAttribute("sessionUsername");
String applicaString = (String)application.getAttribute("appUsername");
*/
%>
<%-- <br>
the name is : <%=username%>
<br>
the session name is : <%=sessionName%>
<br>
the application name is : <%=applicaString%>
--%>
<br>
the request Scope name is : <%=request.getAttribute("requestScope")%>
<br>
the sessionScope name is : <%=session.getAttribute("sessionScope")%>
<br>
the appication Scope name is : <%=application.getAttribute("applicationScope")%>
<br>
the page Scope name is : <%=pageContext.getAttribute("requestParams")%>我将以下三行代码从：
the request Scope name is : <%=pageContext.getAttribute("requestScope")%>
the sessionScope name is : <%=pageContext.getAttribute("sessionScope")%>
the appication Scope name is : <%=pageContext.getAttribute("applicationScope")%>至：
the request Scope name is : <%=request.getAttribute("requestScope")%>
the sessionScope name is : <%=session.getAttribute("sessionScope")%>
the appication Scope name is : <%=application.getAttribute("applicationScope")%>页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/45183112
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