多线程下载的例子很好的

package org.atomic.iptv.download; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.net.ConnectException; import java.net.URL; import java.util.List; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import org.atomic.iptv.Constants; public class Menuloader implements Runnable { private String filePath = null; private List<String> fileList = null; private int threadNum = 1; private static int threadID = 1; private boolean speaker = false; private String url; private String encode; public Menuloader(List<String> fileList) { Constants constants = Constants.getInstance(); this.filePath = constants.getFilePath(); this.fileList = fileList; this.speaker = constants.isSpeaker(); this.url = constants.getUrl(); this.threadNum = constants.getThreadNum(); encode = getEncode(url); filePath = preOP(preOP(filePath,"\\") + encode,"\\"); } public Menuloader(Constants constants, List<String> fileList) { this.filePath = constants.getFilePath(); this.fileList = fileList; this.speaker = constants.isSpeaker(); this.url = constants.getUrl(); this.threadNum = constants.getThreadNum(); encode = getEncode(url); filePath = preOP(preOP(filePath,"\\") + encode,"\\"); } public void run() { if (fileList != null) { try { downloadFiles(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public void downloadFiles() throws IOException { int id = threadID++; if (speaker) System.out.println("Thread " + id + " is starting!"); createFile(filePath); try { for (String name : fileList) { downloadFile(name); } } catch (ConnectException e) { System.out.println("Connection time out"); return; } if (speaker) System.out.println("Thread " + id + " has finished!"); } public void mutiDownLoad(int threadNum) { this.threadNum = threadNum; if (fileList != null) { mutiDownLoad(fileList); } } public void mutiDownLoad() { if (fileList != null) { mutiDownLoad(fileList); } } private void createFile(String fileFath) throws IOException { File file = new File(fileFath); if (!file.exists()) { file.mkdir(); } } /** * @param name * @throws IOException */ private void downloadFile(String name) throws IOException { url = preOP(url,"/"); String urlAddress = url + name + ".xml"; URL url = new URL(urlAddress); BufferedReader in = null; try { in = new BufferedReader(new InputStreamReader(url.openStream(), encode)); } catch (FileNotFoundException e) { if (speaker) System.out.println("The file:" + name + ".xml is not existed!"); return; } File file = new File(filePath + name + ".xml"); if (!file.exists()) file.createNewFile(); BufferedWriter out = new BufferedWriter(new OutputStreamWriter( new FileOutputStream(file), encode)); StringBuilder str = new StringBuilder(); String temp = null; while ((temp = in.readLine()) != null) { str.append(temp); } out.write(str.toString()); in.close(); out.close(); if (speaker) System.out.println(filePath + name + " succeed!"); } private void mutiDownLoad(List<String> fileList) { int averListSize = 0; int fromIndex = 0; int toIndex = 0; if (fileList.size() / threadNum < 5) { threadNum = fileList.size() / 5; averListSize = 5; } else { averListSize = fileList.size() / threadNum; } ExecutorService exec = Executors.newCachedThreadPool(); for (int i = 0; i < threadNum; i++) { toIndex = fromIndex + averListSize; exec.execute(new Menuloader(fileList.subList(fromIndex, toIndex))); fromIndex = toIndex; } if (fromIndex < fileList.size()) exec.execute(new Menuloader(fileList.subList(fromIndex, fileList .size()))); exec.shutdown(); } private String getEncode(String url) { if (url.endsWith("/")) { url = url.substring(0, url.length() - 1); } int index = url.lastIndexOf("/"); return url.substring(index + 1, url.length()); } private String preOP(String url, String part) { if (!url.endsWith(part)) { url += part; } return url; } }