The UploadedFile is null , Primefaces [duplicate] - jsf

Question

This question already has answers here:
How to use PrimeFaces p:fileUpload? Listener method is never invoked or UploadedFile is null / throws an error / not usable
(11 answers)
Closed 6 years ago.
The UploadedFile is null when I clicked the commandButton. What's Wrong?
in the form tag i insert the code : enctype="multipart/form-data"
<h:form enctype="multipart/form-data">
<p:fileUpload mode="simple" value="#{b_cargar_tbl.file}" />
<p:commandButton actionListener="#{b_cargar_tbl.upload()}" value="Send" ajax="false" />
</h:form>
The code of bean is:
private UploadedFile file;
public UploadedFile getFile() {
return file;
}
public void setFile(UploadedFile file) {
this.file = file;
}
public void upload() {
if(file != null) {
FacesMessage message = new FacesMessage("Succesful", file.getFileName() + " is uploaded.");
FacesContext.getCurrentInstance().addMessage(null, message);
}
}
The web.xlm
<context-param>
<param-name>primefaces.UPLOADER</param-name>
<param-value>auto|native|commons</param-value>
</context-param>
<filter>
<filter-name>PrimeFaces FileUpload Filter</filter-name>
<filter-class>org.primefaces.webapp.filter.FileUploadFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>PrimeFaces FileUpload Filter</filter-name>
<servlet-name>Faces Servlet</servlet-name>
</filter-mapping>

Answer 1

this solution:
add atribute fileUploadListener into p:fileUpload and create in your managedbean class method with one parametr listener FileUploadEvent
example:
<p:commandButton actionListener="#{b_cargar_tbl.upload()}" value="Send"
fileUploadListener="#{b_cargar_tbl.upload}" ajax="false" />
in your managed bean add method:
public void upload(FileUploadEvent event) {
System.err.println("event.getFile().getFileName() = " + event.getFile().getFileName());
try {
copyFile(event.getFile().getFileName(), event.getFile().getInputstream());
} catch (Exception ex) {
ex.printStackTrace();
}
}