Java spring 应用程序找不到对象的属性
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时间：2020-08-13 09:40:44 来源:igfitidea点击:
spring app not finding property on object
提问by CodeMed
I have an object calendarof type AppointmentCalendar. In a jsp called calendar.jsp, I call one of calendar's properties as calendar.day. But I am getting an error saying:
我有一个calendar类型的对象AppointmentCalendar。在称为 .jsp 的 jsp 中calendar.jsp，我将其中一个calendar属性称为calendar.day. 但我收到一条错误消息：
org.springframework.expression.spel.SpelEvaluationException: EL1008E:(pos 9): Field or property 'day' cannot be found on object of type
Can anyone show me how to resolve this?
谁能告诉我如何解决这个问题？
Here is the part of calendar.jspwhich refers to the dayproperty:
以下是calendar.jsp其中涉及该day属性的部分：
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://www.springframework.org/tags" prefix="spring" %>
<%@ taglib prefix="joda" uri="http://www.joda.org/joda/time/tags" %>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<div id="appointmentDay" class="prepend-6 span-4 alt">
<spring:eval expression="calendar.day" />
</div>
<div id="appointmentNavigation" class="span-3 append-11 last alt">
<c:url var="previousLink" value="/calendar">
<c:param name="day" value="${calendar.previousDay}" />
</c:url>
<a href="${previousLink}">Previous</a>
<c:url var="nextLink" value="/calendar">
<c:param name="day" value="${calendar.nextDay}" />
</c:url>
<a href="${nextLink}">Next</a>
</div>
<div id="dayPicker" class="span-6"></div>
... other irrelevant code
</body>
</html>
Here is the part of EncounterControllerwhich manages the /calendarurl pattern:
这是EncounterController管理/calendarurl 模式的部分：
@RequestMapping("/calendar")
public String showCalendar(Model model) {
LocalDate today = new LocalDate();
System.out.println("------------------------ in controller, day of month is: "+today.getDayOfMonth());
AppointmentCalendar calendar = new AppointmentCalendar(today); // Or whatever you do to create it
model.addAttribute("calendar", calendar);
return "appointments/calendar";
}
Here is AppointmentCalendar :
这是 AppointmentCalendar ：
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.joda.time.LocalDate;
import org.joda.time.LocalTime;
import org.springframework.format.annotation.DateTimeFormat;
public class AppointmentCalendar {
@DateTimeFormat(style="F-")
private LocalDate day;
private List<Provider> providers;
private List<Encounter> encounters;
public AppointmentCalendar(LocalDate day) {
this.day = day;
System.out.println(":::::::::::::::::::::::::: in AppointmentCalendar constructor, dayOfMonth is: "+day.getDayOfMonth());
}
public void setProviders(List<Provider> doctors) {
this.providers = doctors;
encounters = new ArrayList<Encounter>();
for (int i = 0; i < 9; i++) {encounters.add(null);}
}
public void addEncounter(Encounter appointment) {
int blockIndex = appointment.getDateTime().getHourOfDay() - 8;
encounters.add(appointment);
}
public Long getDayMillis() {
return day.toDateTimeAtStartOfDay().getMillis();
}
public List<LocalTime> getBlocks() {
List<LocalTime> blocks = new ArrayList<LocalTime>(9);
LocalTime time = new LocalTime(8, 0);
for (int i = 0; i < 9; i++) {
blocks.add(time);
time = time.plusMinutes(60);
}
return blocks;
}
public Long getBlockMillis(LocalTime block) {return day.toDateTime(block).getMillis();}
public Date getStartOfDay() {return day.toDateTime(getBlocks().get(0)).toDate();}
public Date getEndOfDay() {return day.toDateTime(getBlocks().get(8)).plusMillis(60).toDate();}
// resource links
public LocalDate getPreviousDay() {return day.minusDays(1);}
public LocalDate getNextDay() {return day.plusDays(1);}
// internal
private List<Encounter> createEncounterList(int size) {
List<Encounter> appointments = new ArrayList<Encounter>(size);
for (int i = 0; i < size; i++) {appointments.add(null);}
return appointments;
}
}
And here is the complete stack trace. Notice that they system.out.println()output at the start shows that the methods are firing in the correct order, and that there is a value for the dayproperty:
这是完整的堆栈跟踪。请注意，它们system.out.println()在开始时的输出表明方法以正确的顺序触发，并且该day属性有一个值：
------------------------ in controller, day of month is: 6
:::::::::::::::::::::::::: in AppointmentCalendar constructor, dayOfMonth is: 6
Feb 6, 2014 1:34:21 PM org.apache.jasper.compiler.TldLocationsCache tldScanJar
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Feb 6, 2014 1:34:22 PM org.apache.catalina.core.ApplicationDispatcher invoke
SEVERE: Servlet.service() for servlet jsp threw exception
org.springframework.expression.spel.SpelEvaluationException: EL1008E:(pos 9): Field or property 'day' cannot be found on object of type 'org.springframework.samples.knowledgemanager.model.AppointmentCalendar'
at org.springframework.expression.spel.ast.PropertyOrFieldReference.readProperty(PropertyOrFieldReference.java:216)
at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:85)
at org.springframework.expression.spel.ast.PropertyOrFieldReference.access##代码##0(PropertyOrFieldReference.java:43)
at org.springframework.expression.spel.ast.PropertyOrFieldReference$AccessorLValue.getValue(PropertyOrFieldReference.java:346)
at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:82)
at org.springframework.expression.spel.ast.SpelNodeImpl.getTypedValue(SpelNodeImpl.java:102)
at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:98)
at org.springframework.web.servlet.tags.EvalTag.doEndTag(EvalTag.java:126)
at org.apache.jsp.WEB_002dINF.jsp.appointments.calendar_jsp._jspx_meth_spring_005feval_005f0(calendar_jsp.java:217)
at org.apache.jsp.WEB_002dINF.jsp.appointments.calendar_jsp._jspService(calendar_jsp.java:114)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:487)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339)
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:263)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1208)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:992)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:939)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.github.dandelion.datatables.core.web.filter.DatatablesFilter.doFilter(DatatablesFilter.java:73)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.github.dandelion.datatables.extras.servlet2.filter.DatatablesFilter.doFilter(DatatablesFilter.java:71)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Feb 6, 2014 1:34:22 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [KnowledgeManager] in context with path [/KnowledgeManager] threw exception [org.springframework.expression.spel.SpelEvaluationException: EL1008E:(pos 9): Field or property 'day' cannot be found on object of type 'org.springframework.samples.knowledgemanager.model.AppointmentCalendar'] with root cause
org.springframework.expression.spel.SpelEvaluationException: EL1008E:(pos 9): Field or property 'day' cannot be found on object of type 'org.springframework.samples.knowledgemanager.model.AppointmentCalendar'
at org.springframework.expression.spel.ast.PropertyOrFieldReference.readProperty(PropertyOrFieldReference.java:216)
at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:85)
at org.springframework.expression.spel.ast.PropertyOrFieldReference.access##代码##0(PropertyOrFieldReference.java:43)
at org.springframework.expression.spel.ast.PropertyOrFieldReference$AccessorLValue.getValue(PropertyOrFieldReference.java:346)
at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:82)
at org.springframework.expression.spel.ast.SpelNodeImpl.getTypedValue(SpelNodeImpl.java:102)
at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:98)
at org.springframework.web.servlet.tags.EvalTag.doEndTag(EvalTag.java:126)
at org.apache.jsp.WEB_002dINF.jsp.appointments.calendar_jsp._jspx_meth_spring_005feval_005f0(calendar_jsp.java:217)
at org.apache.jsp.WEB_002dINF.jsp.appointments.calendar_jsp._jspService(calendar_jsp.java:114)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:487)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339)
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:263)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1208)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:992)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:939)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.github.dandelion.datatables.core.web.filter.DatatablesFilter.doFilter(DatatablesFilter.java:73)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.github.dandelion.datatables.extras.servlet2.filter.DatatablesFilter.doFilter(DatatablesFilter.java:71)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
采纳答案by peter.petrov
You should add a public getDay()method to AppointmentCalendar.
Spring needs this getter to get the value of day.
您应该将公共getDay()方法添加到AppointmentCalendar.
Spring 需要这个 getter 来获取day.
In general when using Spring managed beans/classes
always add the respective getter and setter methods.
一般来说，当使用 Spring 管理的 bean/classes 时，
总是添加各自的 getter 和 setter 方法。
