HTTP Status 500 – Internal Server Error


Type Exception Report

Message An exception occurred processing [itemDetailView.jsp] at line [17]

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.apache.jasper.JasperException: An exception occurred processing [itemDetailView.jsp] at line [17]

14: User user = (User) request.getAttribute("user");
15: String msg = (String) request.getAttribute("msg");
16: int totalItems = 0;
17: for (CartItem cartItem : cartList) {
18: 	totalItems += cartItem.getAmount();
19: }
20: String username = "";


Stacktrace:
	org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:610)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:499)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:379)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:327)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
	aiwa.controller.ItemDetailController.doGet(ItemDetailController.java:49)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:529)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)

Root Cause

java.lang.NullPointerException: Cannot invoke "java.util.List.iterator()" because "cartList" is null
	org.apache.jsp.itemDetailView_jsp._jspService(itemDetailView_jsp.java:142)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:466)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:379)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:327)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
	aiwa.controller.ItemDetailController.doGet(ItemDetailController.java:49)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:529)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)

Note The full stack trace of the root cause is available in the server logs.


Apache Tomcat/9.0.80