有两个JSP,其中login.jsp用来登录,另一个user.jsp是登录后跳转到的页面,现在发现在login.jsp中为session赋值后在user.jsp中无法读取。
login.jsp代码片段session.setAttribute("uid",user.getUid());user.jsp代码片段uid = Integer.parseInt(session.getAttribute("uid").toString());Tomcat错误提示
description The server encountered an internal error () that prevented it from fulfilling this request.
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:451)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
filter.EncodingFilter.doFilter(EncodingFilter.java:30)
root causejava.lang.NullPointerException
org.apache.jsp.user_jsp._jspService(user_jsp.java:53)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
filter.EncodingFilter.doFilter(EncodingFilter.java:30)这段程序在Tomcat5.5.25上正常运行,这个错误提示是5.5.27上出来的~
请大牛指教!
login.jsp代码片段session.setAttribute("uid",user.getUid());user.jsp代码片段uid = Integer.parseInt(session.getAttribute("uid").toString());Tomcat错误提示
description The server encountered an internal error () that prevented it from fulfilling this request.
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:451)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
filter.EncodingFilter.doFilter(EncodingFilter.java:30)
root causejava.lang.NullPointerException
org.apache.jsp.user_jsp._jspService(user_jsp.java:53)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
filter.EncodingFilter.doFilter(EncodingFilter.java:30)这段程序在Tomcat5.5.25上正常运行,这个错误提示是5.5.27上出来的~
请大牛指教!
在这里楼主并没有把值传进去,所以会报空指针错误
<c:set value="要放的值" var="userId" scope="session">
取值
${userId}
根据你写的代码。只能是这有可能出现空指针的了
这句的 user.getUid()=null 了
所以出错。
在这里楼主并没有把值传进去,所以会报空指针错误
是吧你想要的数据发送的下个请求地址上,而不是放到session里去.
requset.getSession.setAttribute(....)才是把你要的数据仍到Session里去.在所有页面都能取到值