处理jsp传参中异常
测试目的：
当页面a.jsp向页面b.jsp提交
b.jsp通过request.getParameter( "属性名 ")获得相应提交值
当a.jsp没有提交相应属性值时，通过Exception_other类来处理该异常
问题：报异常
----------------- a.jsp ---------------
<%@ page language= "java " import= "java.util.* " pageEncoding= "UTF-8 "%>
<html>
<head> </head>
<body>
<form name= "form1 " method= "post " action= "b.jsp ">
请输入用户姓名： <input type= "text " name= "username ">
<input type= "submit " name= "Submit " value= "提交 ">
</form>
</body>
</html>
---------------- b.jsp -----------------
<%@ page language= "java " import= "java.util.*,com.cn.Exception_other " pageEncoding= "UTF-8 "%>
<html>
<body>
<%
String username =
Exception_other.operatGetMothod(request, "username ");
%>
<%=username%>
</body>
</html>
----------- com.cn.Exception_other ----------
package com.cn;
import javax.servlet.http.HttpServletRequest;
public class Exception_other {
private static String getStr = " ";
public static String operatGetMothod(HttpServletRequest request,String str){
try {
getStr = request.getParameter(str);
if(getStr.equals(str)){
getStr = str;
}else{
getStr = " ";
}
} catch (Exception e) {
getStr = " ";
}
return getStr;
}
}
========================所报错误========================
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: javax/servlet/http/HttpServletRequest
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:825)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:758)
org.apache.jsp.b_jsp._jspService(b_jsp.java:63)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause
新版论坛使用之体会,该怎么处理 