我不太确定它出了什么问题。它会一直显示这些错误消息。似乎有一些空值,但我似乎无法识别和纠正这些问题。有谁能帮忙看一眼吗?
更新:我认为问题应该出现在managedbean或post构造方法中,但我似乎找不到原因。
汇总错误消息
System exception occurred during an invocation on EJB RequestController,
method: public entity.Request ejb.session.stateless.RequestController.retrieveRequestByRequestId(java.lang.Long) throws exception.RequestNotFoundException
Caused by: java.lang.IllegalArgumentException: An instance of a null PK has been incorrectly provided for this find operation.
DeleteRequestManagedBean中的后期构造
@PostConstruct
public void postConstruct() {
requestId = (Long)FacesContext.getCurrentInstance().getExternalContext().getFlash().get("request");
try {
request = requestControllerLocal.retrieveRequestByRequestId(requestId);
}
//Removed some irrelevant codes
DeleteRequestManagedBean中的删除请求方法
public void deleteRequest() {
requestControllerLocal.deleteRequest(requestId);
FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_INFO, "Request has been successfully deleted: ", null));
}
用于删除xhtml中的请求的按钮
<p:commandButton value="Remove" icon ="fa fa-fw fa-remove" styleClass="p-btnDelete" actionListener="#{deleteRequestManagedBean.deleteRequest}"/>
RequestController (无状态会话Delete)中的删除请求方法
@Override
public void deleteRequest(Long requestId) throws RequestNotFoundException, DeleteRequestException {
//Removed some irrelevant codes
Request requestToDelete = retrieveRequestByRequestId(requestId);
requestToDelete.getCategory().getRequests().remove(requestToDelete);
em.remove(requestToDelete);
}
如果您还需要任何其他信息,请随时告诉我。谢谢!
发布于 2019-04-16 09:09:11
事实证明,我的managedbean和xhtml页面都有问题。
我必须使用getAttribute(),并从xhtml页面获取属性"postRToDelete“。在没有检索到它的情况下,它一直给我空指针,非法参数异常。
这里是为了那些和我犯了同样错误的人的利益。
DeleteRequestManagedbean
Request request = (Request) event.getComponent().getAttributes().get("postRToDelete");
xhtml页面
<p:commandButton value="Delete" icon ="fa fa-fw fa-remove" styleClass="p-btnDelete" actionListener="#{profileManagedBean.deletePostedRequest}" update="@form">
<!--attribute from here-->
<f:attribute name="postRToDelete" value="#{postedReq}"/>
</p:commandButton>
https://stackoverflow.com/questions/55690255
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