在JSP中使用request.getParameter会导致NullPointerException [英] Use of request.getParameter in JSP results in NullPointerException
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问题描述
试图获取查询字符串参数并在JSP页面中采取适当的措施.
Trying to get a query string parameter and take an appropriate action in a JSP page.
这是一个代码段:
<%@ page import="com.companyx.portal.model.LDAPAttributes" %>
<%@ page import="com.companyx.portal.service.LDAPAttributesLocalServiceUtil" %>
<%@ page import="com.liferay.portal.model.User" %>
<%@ page import="com.liferay.portal.util.PortalUtil" %>
<%@ page import="javax.servlet.http.HttpServletRequest" %>
<%
User user = PortalUtil.getUser(request);
String screenName = user.getScreenName();
LDAPAttributes attr = LDAPAttributesLocalServiceUtil.getLDAPAttributes(screenName);
String store = attr.getLegacyStoreNo();
String org = request.getParameter("org");
%>
...more code here...
<html>
...html code here...
<form name="LoginForm" action="check_login.php">
<input type="hidden" name="LOGIN_NAME" size="20" value="<%= store %>" />
<input type="hidden" name="LOGIN_PASSWORD" size="20" value="<%= store %>" />
<input type="hidden" name="ORGANIZATION" value="<%= org %>" />
</form>
缺少以下几行时:
String org = request.getParameter("org");
...
<input type="hidden" name="ORGANIZATION" value="<%= org %>" />
该脚本可以正常工作，但是我需要从查询字符串中捕获一个'org'参数，将其写入生成的表单中并提交.但是，当这些行出现时，我会收到500错误.
The script works just fine, but I need to capture an 'org' parameter from the query string, write it into the generated form and submit it. When those lines are present, though, I get a 500 error.
有什么想法吗?
推荐答案
可能是您正在使用PortletRequest而不是HttpServletRequest.
Chances are you're working with the PortletRequest and not the HttpServletRequest.
HttpServletRequest realRequest = PortalUtil.getHttpServletRequest(request);
String organization = realRequest.getParameter("org");
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