filemanager.java

MyDownloader 是一款使用 http 协议(RFC 1867)用于下载一个或多个文件到本地的简单易用的收费 Java 程序.使用托拽操作,你可以在一个页面内下载多个文件.在下载文件的过程当中

/*
 * Copyright 2007 JavaAtWork All rights reserved.
 * Use is subject to license terms.
 */
package com.javaatwork.mydownloader;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.StringTokenizer;
import java.util.Vector;

import com.javaatwork.mydownloader.utils.Logger;
import com.javaatwork.mydownloader.utils.Parameters;
import com.javaatwork.mydownloader.utils.Version;

/**
 * Class for retrieving the download files out of the
 * the applet parameter 'files'.
 * 
 * @author Johannes Postma
 */
public class FileManager {

	/**
	 * Returns the initial files to download.
	 * 
	 * @param codeBase The codebase of the applet.
	 * @return The initial files to download.
	 */
	public static DownloadFile [] getFilesToDownload(URL codeBase) {
		
		String list = Parameters.getParameter(Parameters.FILES, null);
		Vector fileList = new Vector();
		
		// check if demo version
		if (Version.DEMO_EDITION) {
			
			try {
				fileList.addElement(new DownloadFile(new URL("http://www.javaatwork.com/java-download-applet/files/mydownloader.doc")));
				fileList.addElement(new DownloadFile(new URL("http://www.javaatwork.com/java-download-applet/files/mydownloader.xls")));
				fileList.addElement(new DownloadFile(new URL("http://www.javaatwork.com/java-download-applet/files/castle.jpg")));
				fileList.addElement(new DownloadFile(new URL("http://www.javaatwork.com/java-download-applet/files/kid.jpg")));
			} catch (MalformedURLException e) {
				
				// do nothing
				DownloadFile [] files = new DownloadFile[0];
				return files;
			}
			
		} else {
		
			if (list == null) {
				DownloadFile [] files = new DownloadFile[0];
				return files;
			} else {
				
				StringTokenizer tokens = new StringTokenizer(list, ";");
			
				while (tokens.hasMoreTokens()) {
					String file = tokens.nextToken();
					
					String part [] = file.split("#:#");
									
					URL url = null;
					
					try {
						
						if (!part[0].startsWith("http")) {
							url = new URL(codeBase, part[0]);
						} else {
							url = new URL(part[0]);
						}
						
						if (part.length == 2) {
							fileList.addElement(new DownloadFile(url, part[1]));
						} else {
							fileList.addElement(new DownloadFile(url));
						}
					} catch (MalformedURLException e) {
						
						Logger.log("FileManager", "getFilesToDownload", part[0] + " is not a valid url.");
					}
				}
			}
		}
		
		return (DownloadFile[])fileList.toArray(new DownloadFile[fileList.size()]);
	}
}