zkfileitemfactory.java

非常接近C/S操作方式的Java Ajax框架－ZK 用ZK框架使你的B/S应用程序更漂亮更易操作。 官网：www.zkoss.org

/* ZkFileItemFactory.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Mon Aug 14 19:21:26     2006, Created by tomyeh
}}IS_NOTE

Copyright (C) 2006 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
	This program is distributed under GPL Version 2.0 in the hope that
	it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zk.au.http;

import java.io.File;
import java.io.OutputStream;
import java.io.IOException;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;

import org.zkoss.util.logging.Log;
import org.zkoss.zk.ui.Desktop;
import org.zkoss.zk.ui.impl.Attributes;

/**
 * The file item factory that monitors the progress of uploading.
 *
 * @author tomyeh
 */
/*package*/ class ZkFileItemFactory extends DiskFileItemFactory {
	private static final Log log = Log.lookup(ZkFileItemFactory.class);

	private final Desktop _desktop;
	/** The total length (content length). */
	private final long _cbtotal;
	/** # of bytes being received x 100. */
	private long _cbrcv;

	/*package*/ ZkFileItemFactory(Desktop desktop, HttpServletRequest request) {
    	setSizeThreshold(1024*128);	// maximum size that will be stored in memory

		_desktop = desktop;

		long cbtotal = 0;
		String ctlen = request.getHeader("content-length");
		if (ctlen != null)
			try {
				cbtotal = Long.parseLong(ctlen.trim());
				//if (log.debugable()) log.debug("content-length="+cbtotal);
			} catch (Throwable ex) {
				log.warning(ex);
			}
		_cbtotal = cbtotal;

		_desktop.setAttribute(Attributes.UPLOAD_PERCENT, new Integer(0));
		_desktop.setAttribute(Attributes.UPLOAD_SIZE, new Long(_cbtotal));
	}

	/*packageg*/ void onProgress(int diff) {
		int percent = 0;
		if (_cbtotal > 0) {
			_cbrcv += diff * 100;
			percent = (int)(_cbrcv / _cbtotal);
		}

		_desktop.setAttribute(Attributes.UPLOAD_PERCENT, new Integer(percent));
	}

	//-- FileItemFactory --//
    public FileItem createItem(String fieldName, String contentType,
	boolean isFormField, String fileName) {
		return new ZkFileItem(fieldName, contentType, isFormField, fileName,
			getSizeThreshold(), getRepository());

	}

	//-- helper classes --//
	/** FileItem created by {@link ZkFileItemFactory}.
	 */
	/*package*/ class ZkFileItem extends DiskFileItem {
		/*package*/ ZkFileItem(String fieldName, String contentType,
		boolean isFormField, String fileName, int sizeThreshold,
		File repository) {
			super(fieldName, contentType, isFormField,
				fileName, sizeThreshold, repository);
		}

		/** Returns the charset by parsing the content type.
		 * If none is defined, UTF-8 is assumed.
		 */
	    public String getCharSet() {
			final String charset = super.getCharSet();
			return charset != null ? charset: "UTF-8";
		}
		public OutputStream getOutputStream() throws IOException {
			final OutputStream out = super.getOutputStream();
			if(isFormField()) return out;
			return new ZkOutputStream(out);
		}
	}

	/** The output stream.
	 */
	/*package*/ class ZkOutputStream extends OutputStream {
		private final OutputStream _out;
		/*package*/ ZkOutputStream(OutputStream out) {
			_out = out;
		}

		public void close() throws IOException {
			_out.close();
		}
		public void flush() throws IOException {
			_out.flush();
		}

		public void write(byte[] bytes, int offset, int len) throws IOException {
			_out.write(bytes, offset, len);
			onProgress(len);
		}

		public void write(byte[] bytes) throws IOException {
			_out.write(bytes);
			onProgress(bytes.length);
		}

		public void write(int b) throws IOException {
			_out.write(b);
			onProgress(1);
		}
	}	
}