我正在按照教程使用<s:checkboxlist>
标记创建多个复选框。
我的项目和教程之间的区别在于它使用List<String>
生成复选框列表,而我有List<KMCountry>
(并且需要从文本值生成复选框列表KMCountry
对象的属性。
动作
List<KMCountry> kmCountryListAll;
public List<KMCountry> getKmCountryListAll() {
return kmCountryListAll;
}
模型
@Entity
@Table(name = "KM_COUNTRY")
public class KMCountry implements Serializable {
@Id
@GeneratedValue
private Long idCountry;
@Column(name = "country")
private String name;
@Column(name = "workingHours")
private String workingHours;
// Getters and setters
}
JSP
<s:checkboxlist label="Select Countries"
list="kmCountryListAll"
listKey="idCountry"
listValue="name"
value="defaultCountry" />
但这种方式不起作用。
使用调试器我看到它进入getKmCountryListAll()
方法并返回kmCountryListAll
列表,但在视图中我收到以下错误:
Expression parameters.name is undefined on line 38, column 32 in template/simple/checkboxlist.ftl.
The problematic instruction:
----------
==> ${parameters.name?html} [on line 38, column 30 in template/simple/checkboxlist.ftl]
in user-directive s.iterator [on line 25, column 5 in template/simple/checkboxlist.ftl]
in include "/${parameters.templateDir}/simple/checkboxlist.ftl" [on line 25, column 1 in template/css_xhtml/checkboxlist.ftl]
----------
Java backtrace for programmers:
----------
freemarker.core.InvalidReferenceException: Expression parameters.name is undefined on line 38, column 32 in template/simple/checkboxlist.ftl.
at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:124)
at freemarker.core.Expression.getStringValue(Expression.java:118)
at freemarker.core.Expression.getStringValue(Expression.java:93)
at freemarker.core.StringBuiltins$StringBuiltIn._getAsTemplateModel(StringBuiltins.java:71)
at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
at freemarker.core.Expression.getStringValue(Expression.java:93)
at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
at freemarker.core.Environment.visit(Environment.java:210)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:210)
at freemarker.core.Environment.visit(Environment.java:299)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:130)
at freemarker.core.Environment.visit(Environment.java:210)
at freemarker.core.IfBlock.accept(IfBlock.java:82)
at freemarker.core.Environment.visit(Environment.java:210)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:210)
at freemarker.core.Environment.include(Environment.java:1483)
at freemarker.core.Include.accept(Include.java:169)
at freemarker.core.Environment.visit(Environment.java:210)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:210)
at freemarker.core.Environment.process(Environment.java:190)
at freemarker.template.Template.process(Template.java:237)
at org.apache.struts2.components.template.FreemarkerTemplateEngine.renderTemplate(FreemarkerTemplateEngine.java:157)
at org.apache.struts2.components.UIBean.mergeTemplate(UIBean.java:559)
at org.apache.struts2.components.UIBean.end(UIBean.java:513)
at org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:42)
at jsp_servlet._countryarea.__showmultiselectcountry._jsp__tag0(__showmultiselectcountry.java:107)
at jsp_servlet._countryarea.__showmultiselectcountry._jspService(__showmultiselectcountry.java:70)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:34)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:300)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:183)
at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:526)
at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:253)
at org.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:157)
at org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186)
at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:373)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:277)
at egp.prc.km.utils.interceptors.LiferayAjaxInterceptor.intercept(LiferayAjaxInterceptor.java:28)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:263)
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:248)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:133)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:270)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
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:248)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:190)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:498)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
at org.apache.struts2.dispatcher.ng.servlet.StrutsServlet.service(StrutsServlet.java:76)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:300)
at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56)
at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:27)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3715)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3681)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2277)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2183)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1454)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:178)
<17-mar-2015 14.57.09 CET> <Error> <HTTP> <BEA-101020> <[ServletContext@771696009[app:KM_Web_war_exploded module:KM-Web-1.0.0 path:/KMPortlets spec-version:2.5]] Servlet failed with Exception
java.lang.NullPointerException
at weblogic.servlet.internal.ServletResponseImpl.sendContentError(ServletResponseImpl.java:611)
at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:655)
at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:819)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:519)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
Truncated. see log file for complete stacktrace
>
为什么呢?我错过了什么?我该如何解决这个问题?
答案 0 :(得分:3)
您需要将name
属性添加到<s:checkboxlist>
代码
答案 1 :(得分:1)
由于&#34;表达式parameters.name在第38行,template / simple / checkboxlist.ftl中的第32列未定义。&#34;说,你应该为参数bean添加一个NAME属性,或者参数是什么。