                        課程
                    
                        /后端開發
                        
                            /Java
                        
                        /JAVA遇見HTML——JSP篇

空指針異常？？

java.lang.NullPointerException

type?Exception report

message?An exception occurred processing JSP page /request.jsp at line 30

description?The server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: An exception occurred processing JSP page /request.jsp at line 30

27: ? ? ?”¨??·??????<%=request.getParameter("username") %><br>
28: ? ? ??±?￥????<%
29: ? ? String[] favorites = request.getParameterValues("favorite");
30: ? ? for(int i=0;i<favorites.length;i++)
31: ? ? {
32: ? ? out.println(favorites[i]+"  ");
33: ? ? }

代碼如下

? <body>

? ? <h1>request內置對象</h1>

? ? 用戶名：<%=request.getParameter("username") %><br>

? ? 愛好：<%

? ? String[] favorites = request.getParameterValues("favorite");

? ? for(int i=0;i<favorites.length;i++)

? ? {

? ? out.println(favorites[i]+"  ");

? ? }

? ? %>