atributos etiqueta p:fileUpload

<p:fileUpload 
   id="registryUpload"
   value="#{bean.zipFile}"
   allowTypes="/(\.|\/)(zip)$/i" 
   sizeLimit="524288000" 
   mode="simple"
   skinSimple="true" 
   invalidFileMessage="Invalid file type"
   messageTemplate="Can't upload file {name}. It must be a .zip file"
   required="true" 
   requiredMessage="You must select the ZIP file to upload"
   update="registryUploadMessage" 
/>
<p:message id="registryUploadMessage" for="registryUpload" />