FreeMarker模板错误！ 在struts2中

我在我的课堂上使用sturts 2注释validation，而在显示操作错误时，我得到了这个奇怪的“FreeMarker模板错误！” 这是我的实体类。

@Entity public class User implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long userid; private String userPhoneNumber; private String userName; private String password; private String full_name; private String useremail; @OneToOne private userType usertypeid; public Long getUserid() { return userid; } public void setUserid(Long userid) { this.userid = userid; } public String getUserPhoneNumber() { return userPhoneNumber; } @RequiredStringValidator(message = "Enter Phone Number",type = ValidatorType.FIELD) public void setUserPhoneNumber(String userPhoneNumber) { this.userPhoneNumber = userPhoneNumber; } public String getUserName() { return userName; } @RequiredStringValidator(message = "Enter User Name",type = ValidatorType.FIELD) public void setUserName(String userName) { this.userName = userName; } public String getPassword() { return password; } @RequiredStringValidator(message = "Enter Password",type = ValidatorType.FIELD) public void setPassword(String password) { this.password = password; } public String getFull_name() { return full_name; } @RequiredStringValidator(message = "Enter Full Name",type = ValidatorType.FIELD) public void setFull_name(String full_name) { this.full_name = full_name; } public String getUseremail() { return useremail; } @RequiredStringValidator(message = "Enter Email Id",type = ValidatorType.FIELD) @EmailValidator(message = "Enter Valid Email Id",type = ValidatorType.FIELD) public void setUseremail(String useremail) { this.useremail = useremail; } public userType getUsertypeid() { return usertypeid; } public void setUsertypeid(userType usertypeid) { this.usertypeid = usertypeid; } } 

这是我的Struts.xml文件操作代码

   /AddUser.jsp userlist  

这是我的jsp页面

    
 
User
 
 User Name 
  
  
 
 
 Full Name 
  
  
 
 
 Contact No 
  
  
 
 
 Email Id 
  
  
 
 
 Password 
  
  
 
 
 User Type 
  
 
 
 
   
 Save  Reset Cancel  
 
 
   

提交表单后，它显示此错误，尽管我提供了有效的详细信息

  org.apache.jasper.JasperException: Expression eKey is undefined on line 32, column 23 in template/simple/fielderror.ftl. - Class: freemarker.core.TemplateObject File: TemplateObject.java Method: assertNonNull Line: 125 - freemarker/core/TemplateObject.java:125:-1 at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:570) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:457) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391) 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.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:164) at org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186) at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:371) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:275) at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265) at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept (AnnotationValidationInterceptor.java:68) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:249) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:249) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept (ScopedModelDrivenInterceptor.java:141) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:139) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.googlecode.s2hibernate.struts2.plugin.interceptors.SessionTransactionInjectorInterceptor.intercept (SessionTransactionInjectorInterceptor.java:157) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54) at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:562) at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter (StrutsPrepareAndExecuteFilter.java:99) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.displaytag.filter.ResponseOverrideFilter.doFilter(ResponseOverrideFilter.java:125) 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:312) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) 

Answer 1

例外是告诉您确切地查找错误的位置：

org.apache.jasper.JasperException：表达式eKey未定义在template / simple / fielderror.ftl的第32行第23行。 – 类：freemarker.core.TemplateObject

罪魁祸首是具有不匹配fieldName的fieldError 。 在测试之后（在评论中）它结果是full_name ，显然下划线没有通过整个链正确处理 ：

  ...  

然后应该使用变量及其Getter和Setter将full_name更改为fullName以便工作：

还要确保拥有所有最新且对齐的struts库和插件，以及正确版本的外部依赖项（Hibernatevalidation器等）

---

那就是说，我想给你一些关于变量命名的建议：

1. 始终将camelCase用于具有多个单词的变量： password是password （单个单词，尽管是复合词），但username和useremail应该是userName和userEmail 。 您已经为单个类的6个变量使用了3种不同的约定…

2. 由于这些是User类的变量，因此请避免变量名称中的冗余user ：userid = id，username = name，userPhoneNumber = phoneNumber等…如果为了更加可读性而在JSP中执行此操作，那么请避免使用标签可能会造成混淆。

如果您正在开始，更改数据库列名称应该不会很痛苦…否则，请为下一个项目保留此建议。

PS：请注意，使用JPA和Hibernate，您可以使用persistence.xml中的此设置自动使用camelCase变量和下划线列名（实体中的phoneNumber ，数据库中的phone_number ）：