- HTTP Status 500 求大神帮忙
-
按照书上写的代码 不是知道为啥总是出现 HTTP Status 500 错误
代码如下：cookie.jsp
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
String str="12";
int number=Integer.parseInt(str);
%>
该数的平方为：<%=number*number %>
<%
Cookie cookie=new Cookie("number",str);
cookie.setMaxAge(600);
response.addCookie(cookie);
%>
到达cookie1cookie1.jsp
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
String str=null;
Cookie[] cookies=request.getCookies();
for(int i=0;i {
if(cookies[i].getName().equals("number"))
{
str=cookies[i].getValue();
break;
}
}
int number=Integer.parseInt(str);
%>
该数的立方为：<%=number*number*number %>错误显示为：
HTTP Status 500 -type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:541)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:435)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)root cause
java.lang.NullPointerException
org.apache.jsp.cookie1_jsp._jspService(cookie1_jsp.java:61)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)note The full stack trace of the root cause is available in the Apache Tomcat/6.0.13 logs.
Apache Tomcat/6.0.13
求大神帮忙啊
这句改一下
.equals("number")
"number".equals(cookies[i].getName())
这句加个判断
if(str!= null){
int number=Integer.parseInt(str);
}
这两个地方可能会有空指针
