HTTP Status 500 - Internal Server Error Type Exception Report Message An exception occurred while processing [/WEB-INF/jsp/user/usermanager.jsp] at line [84] Description The server encountered an unexpected condition

HTTP Status 500 - Internal Server Error
Type Exception Report
Message processed at line [84] [/WEB-INF/jsp/user/ usermanager.jsp]
Description The server encountered an unexpected condition that prevented it from completing the request.
Exceptions
org.apache.jasper.JasperException: Occurred while processing [/WEB-INF/jsp/user/usermanager.jsp] at line [84] Exception
81:
82:
83:
84: <c:forEach items="$userList.list"var="user">85:<tr>86:<td>${user.id}
87: ${user.name}

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)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:171)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:316)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1373)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1118)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1057)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
javax.servlet.http.HttpServlet.service(HttpServlet.java:529)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
根本原因。
java.lang.NumberFormatException: For input string: “list”
java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
java.lang.Integer.parseInt(Integer.java:580)
java.lang.Integer.parseInt(Integer.java:615)
javax.el.ListELResolver.coerce(ListELResolver.java:144)
javax.el.ListELResolver.getValue(ListELResolver.java:64)
org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:125)
org.apache.el.parser.AstValue.getValue(AstValue.java:168)
org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:189)
org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:690)
org.apache.jsp.WEB_002dINF.jsp.user.usermanager_jsp._jspx_meth_c_005fforEach_005f0(usermanager_jsp.java:482)
org.apache.jsp.WEB_002dINF.jsp.user.usermanager_jsp._jspService(usermanager_jsp.java:212)
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)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:171)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:316)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1373)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1118)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1057)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
javax.servlet.http.HttpServlet.service(HttpServlet.java:529)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)

According to the log information, an internal server error with HTTP status 500 occurred. The error occurred on line 84 while processing the /WEB-INF/jsp/user/usermanager.jsp file. The root cause of the exception is a NumberFormatException, the input string "list" cannot be converted to an integer. This exception occurs when trying to parse the value of $userList.lis\; When\; the\; value\; oftis\; reached.\; The\; possible\; reason\; is\; that\; in\; theJSPfile,${userList.list } Expected an integer value as input, but was actually passed a string "list". You need to check your code and make sure ${userList.list} is an integer value, or change it to the correct value.