File Upload and Download

File Upload

You could associate the upload feature to a component, such as Button, Toolbarbutton or Menuitem. In other words, you could make a button or a menu item to upload a file when the user clicks on it.

The implementation is straightaway:

1. Assign the upload attribute to true for the component used to upload a file
2. Assign an event listener to the component for the onUpload event

For example,

<zk>
	<zscript>
	void upload(UploadEvent event) {
		org.zkoss.util.media.Media media = event.getMedia();
		if (media instanceof org.zkoss.image.Image) {
			org.zkoss.zul.Image image = new org.zkoss.zul.Image();
			image.setContent( (org.zkoss.image.Image) media);
			image.setParent(pics);
		} else {
			Messagebox.show("Not an image: "+media, "Error", Messagebox.OK, Messagebox.ERROR);
		}
	}
	</zscript>
	<button label="Upload" upload="true" onUpload="upload(event)"/>
	<vlayout id="pics" />
</zk>

You could control the maximal allowed number of files, the maximal allowed size and other information by use of Button.setUpload(String).

<menupopup>
    <menuitem label="Upload" upload="true,maxsize=-1,native"/>
</menupopup>

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File Download

Filedownload provides a set of utilities to prompt a user for downloading a file from the server to a local folder. For example,

<button label="Download a file" onClick='Filedownload.save("~./zklogo.png", null);'/>

The file could be a static resource, an input stream, a file, a URL and others. Please refer to ZK Component Reference and Filedownload for more information.

Version History

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