java.lang.IllegalStateException: 试图在没有模型的组件上设置模型对象!将 IModel 传递给构造函数或

java.lang.IllegalStateException: Attempt to set a model object on a component without a model! Either pass an IModel to the constructor or

在 wicket 8.x 版本中点击 IndicatingAjaxButton 时出现以下错误。

ERROR | Exception occured: java.lang.IllegalStateException: Attempt to set a model object on a component without a model! Either pass an IModel to the constructor or use #setDefaultModel(new SomeModel(object)). Component: form:savedQuery at org.apache.wicket.Component.setDefaultModelObject(Component.java:2999) at org.apache.wicket.IGenericComponent.setModelObject(IGenericComponent.java:81) at org.apache.wicket.markup.html.form.FormComponent.updateModel(FormComponent.java:1100) at org.apache.wicket.markup.html.form.Form$FormModelUpdateVisitor.component(Form.java:223) at org.apache.wicket.markup.html.form.Form$FormModelUpdateVisitor.component(Form.java:193) at org.apache.wicket.util.visit.Visits.visitPostOrderHelper(Visits.java:274) at org.apache.wicket.util.visit.Visits.visitPostOrderHelper(Visits.java:262) at org.apache.wicket.util.visit.Visits.visitPostOrder(Visits.java:245) at org.apache.wicket.markup.html.form.FormComponent.visitComponentsPostOrder(FormComponent.java:426) at org.apache.wicket.markup.html.form.Form.internalUpdateFormComponentModels(Form.java:1873) at org.apache.wicket.markup.html.form.Form.updateFormComponentModels(Form.java:1838) at org.apache.wicket.markup.html.form.Form.process(Form.java:990) at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:825) at org.apache.wicket.ajax.form.AjaxFormSubmitBehavior.onEvent(AjaxFormSubmitBehavior.java:176) at org.apache.wicket.ajax.AjaxEventBehavior.respond(AjaxEventBehavior.java:127) at org.apache.wicket.ajax.AbstractDefaultAjaxBehavior.onRequest(AbstractDefaultAjaxBehavior.java:598) at org.apache.wicket.core.request.handler.ListenerRequestHandler.internalInvoke(ListenerRequestHandler.java:306) at org.apache.wicket.core.request.handler.ListenerRequestHandler.invoke(ListenerRequestHandler.java:280) at org.apache.wicket.core.request.handler.ListenerRequestHandler.invokeListener(ListenerRequestHandler.java:222) at org.apache.wicket.core.request.handler.ListenerRequestHandler.respond(ListenerRequestHandler.java:208) at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:914) at org.apache.wicket.request.RequestHandlerExecutor.execute(RequestHandlerExecutor.java:65) at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:282) at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:253) at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:221) at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:275) at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:206) at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:299) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:118) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:158) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:158) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilterInternal(BasicAuthenticationFilter.java:204) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:92) at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:77) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215) at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:543) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:688) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:615) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:818) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1623) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748)

final DropDownChoice<String> listSites = (DropDownChoice<String>) new DropDownChoice<String>("savedQueries", new PropertyModel<String>(TestPage.this.getModel(), "selectedValue"), savedQueries).add(new FormComponentUpdatingBehavior() {
private static final long serialVersionUID = 1L;

protected void onUpdate() {
    // Update logic
}


    protected void onError(RuntimeException ex) {
        super.onError(ex);
    }
});
    
listSites.setOutputMarkupId(true);
add(listSites); 


            
TextField savedQuery = new TextField<>("savedQuery"); // CHECK LATER 
savedQuery.setOutputMarkupId(true);
add(savedQuery);

final IndicatingAjaxButton deleteMcb = new IndicatingAjaxButton("delete") {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    
    @Override
    protected void onSubmit(AjaxRequestTarget target) {
        String message=null;
        List<String> savedQueries = null;
        try{
            //on submit process logic
        }catch(Exception e){
            e.printStackTrace();
        }
        
     
        listSites.setChoices(savedQueries);
        listSites.setModelObject(null);
        target.add(listSites);
        savedQuery.setModelObject(null);
        target.add(savedQuery);
        target.add(feedback);
        error(message);
    }
    
};

我在为 TextField 对象添加下面这行代码后解决了这个异常。

savedQuery.setDefaultModel(Model.of(queryName));

queryName 在这里是一个字符串值参数。