                        课程
                    
                        /后端开发
                        
                            /Java
                        
                        /JAVA遇见HTML——JSP篇

空指针异常？？

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: ç”¨æˆ·å��ï¼š<%=request.getParameter("username") %><br>
28: çˆ±å¥½ï¼š<%
29: String[] favorites = request.getParameterValues("favorite");
30: for(int i=0;i<favorites.length;i++)
31: {
32: out.println(favorites[i]+"  ");
33: }

代码如下

<body>

<h1>request内置对象</h1>

用户名：<%=request.getParameter("username") %><br>

爱好：<%

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

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

{

out.println(favorites[i]+"  ");

}