FileUpload

<h:form enctype="multipart/form-data">
    <p:growl showDetail="true"/>
    <p:fileUpload value="#{fileUploadView.file}" mode="simple" disabled="true"/>
    <p:commandButton value="Upload" icon="ui-icon-arrow-u" ajax="false" actionListener="#{fileUploadView.upload}" disabled="true"/>
</h:form>
                    

package org.primefaces.showcase.view.file;

import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.context.FacesContext;

import org.primefaces.model.UploadedFile;

@ManagedBean
public class FileUploadView {
    
    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);
        }
    }
}