我不太确定它有什么问题。它不断显示这些错误消息。似乎有一些空值,但我似乎无法识别和纠正这些问题。任何人都可以帮忙看看吗?
更新:我认为问题应该在managedbean或post构造方法中,但我似乎无法找出原因..
汇总的错误消息
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.
Postconstruct In Delete Request ManagedBean
@PostConstruct
public void postConstruct() {
requestId = (Long)FacesContext.getCurrentInstance().getExternalContext().getFlash().get("request");
try {
request = requestControllerLocal.retrieveRequestByRequestId(requestId);
}
//Removed some irrelevant codes
删除请求方法在DeleteRequestManagedBean中
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}"/>
删除请求控制器中的请求方法(无状态会话Bean)
@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);
}
如果您需要任何其他信息,请随时告诉我。谢谢!
事实证明我的managedbean和xhtml页面都存在问题。
我必须使用getAttribute(),并从xhtml页面获取属性“postRToDelete”。没有得到这个,它继续给我空指针,非法参数例外。
这对于那些犯了同样错误的人来说是有利的。
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>