8). Multidownloading __2

       6.FileDownload

package com.changcheng.net.download;

 

import java.io.File;

import java.io.RandomAccessFile;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.LinkedHashMap;

import java.util.Map;

import java.util.UUID;

import java.util.concurrent.ConcurrentHashMap;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import com.changcheng.download.service.FileService;

import android.content.Context;

import android.util.Log;

 

/**

 * 文件 下载器

 * @author [e-mail]

 *

 */

public class FileDownloader {

         private Context context;

         private FileService fileService;

        

         private static final String TAG = "FileDownloader";

         /* 已下载文件大小 */

         private int downloadSize = 0;

         /* 原始文件大小 */

         private int fileSize = 0;

         /* 线程数 */

         private DownloadThread[] threads;

         /* 下载路径  */

         private URL url;

         /* 本地保存文件 */

         private File saveFile;

         /* 下载记录文件 */

         private File logFile;

         /* 缓存各线程最后下载的位置*/

         private Map data = new ConcurrentHashMap();

         /* 每条线程下载的大小 */

         private int block;

         private String downloadUrl;//下载路径

         /**

          * 获取线程数

          */

         public int getThreadSize() {

                   return threads.length;

         }

         /**

          * 获取文件大小

          * @return

          */

         public int getFileSize() {

                   return fileSize;

         }

         /**

          * 累计已下载大小

          * @param size

          */

         protected synchronized void append(int size) {

                   downloadSize += size;

         }

         /**

          * 更新指定线程最后下载的位置

          * @param threadId 线程id

          * @param pos 最后 下载的位置

          */

         protected void update(int threadId, int pos) {

                   this.data.put(threadId, pos);

         }

         /**

          * 保存记录文件

          */

         protected synchronized void saveLogFile() {

                   this.fileService.update(this.downloadUrl, this.data);

         }

         /**

          * 构建文件下载器

          * @param downloadUrl 下载 路径

          * @param fileSaveDir 文件 保存目录

          * @param threadNum 下载 线程数

          */

         public FileDownloader(Context context, String downloadUrl, File fileSaveDir, int threadNum) {

                   try {

                            this.context = context;

                            this.downloadUrl = downloadUrl;

                            fileService = new FileService(context);

                            this.url = new URL(downloadUrl);

                            if(!fileSaveDir.exists()) fileSaveDir.mkdirs();

                            this.threads = new DownloadThread[threadNum];                                        

                            HttpURLConnection conn = (HttpURLConnection) url.openConnection();

                            conn.setConnectTimeout(6*1000);

                            conn.setRequestMethod("GET");

                            conn.setRequestProperty("Accept", "image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*");

                            conn.setRequestProperty("Accept-Language", "zh-CN");

                            conn.setRequestProperty("Referer", downloadUrl);

                            conn.setRequestProperty("Charset", "UTF-8");

                            conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");

                            conn.setRequestProperty("Connection", "Keep-Alive");

                            conn.connect();

                            printResponseHeader(conn);

                            if (conn.getResponseCode()==200) {

                                     this.fileSize = conn.getContentLength();//根据响应获取文件大小

                                     if (this.fileSize <= 0) throw new RuntimeException("无法获知文件大小 ");

                                                       

                                     String filename = getFileName(conn);

                                     this.saveFile = new File(fileSaveDir, filename);/* 保存 文件 */

                                     Map logdata = fileService.getData(downloadUrl);

                                     if(logdata.size()>0){

                                               data.putAll(logdata);

                                     }

                                     this.block = this.fileSize / this.threads.length + 1;

                                     if(this.data.size()==this.threads.length){

                                               for (int i = 0; i < this.threads.length; i++) {

                                                        this.downloadSize += this.data.get(i+1)-(this.block * i);

                                               }

                                               print("已经下 载的长度"+ this.downloadSize);

                                     }                                   

                            }else{

                                     throw new RuntimeException("服务器响应错误 ");

                            }

                   } catch (Exception e) {

                            print(e.toString());

                            throw new RuntimeException("连接不到下载路径 ");

                   }

         }

         /**

          * 获取文件名

          */

         private String getFileName(HttpURLConnection conn) {

                   String filename = this.url.toString().substring(this.url.toString().lastIndexOf('/') + 1);

                   if(filename==null || "".equals(filename.trim())){//如果获取不到文件名称

                            for (int i = 0;; i++) {

                                     String mine = conn.getHeaderField(i);

                                     if (mine == null) break;

                                     if("content-disposition".equals(conn.getHeaderFieldKey(i).toLowerCase())){

                                               Matcher m = Pattern.compile(".*filename=(.*)").matcher(mine.toLowerCase());

                                               if(m.find()) return m.group(1);

                                     }

                            }

                            filename = UUID.randomUUID()+ ".tmp";//默认取一个文件名

                   }

                   return filename;

         }

        

         /**

          *  开始 下载文件

          * @param listener 监听 下载数量的变化,如果不需要了解实时下载的数量,可以设置为null

          * @return 已下载文件大小

          * @throws Exception

          */

         public int download(DownloadProgressListener listener) throws Exception{

                   try {                    

                            if(this.data.size() != this.threads.length){

                                     this.data.clear();

                                     for (int i = 0; i < this.threads.length; i++) {

                                               this.data.put(i+1, this.block * i);

                                     }

                            }

                            for (int i = 0; i < this.threads.length; i++) {

                                     int downLength = this.data.get(i+1) - (this.block * i);

                                     if(downLength < this.block && this.data.get(i+1)<this.fileSize){ //该线程未完成下载时,继续下载

                                               RandomAccessFile randOut = new RandomAccessFile(this.saveFile, "rw");

                                               if(this.fileSize>0) randOut.setLength(this.fileSize);                               

                                               randOut.seek(this.data.get(i+1));

                                               this.threads[i] = new DownloadThread(this, this.url, randOut, this.block, this.data.get(i+1), i+1);

                                               this.threads[i].setPriority(7);

                                               this.threads[i].start();

                                     }else{

                                               this.threads[i] = null;

                                     }

                            }

                            this.fileService.save(this.downloadUrl, this.data);

                            boolean notFinish = true;//下载未完成

                            while (notFinish) {// 循环判断是否下载完毕

                                     Thread.sleep(900);

                                     notFinish = false;//假定下载完成

                                     for (int i = 0; i < this.threads.length; i++){

                                               if (this.threads[i] != null && !this.threads[i].isFinish()) {

                                                        notFinish = true;//下载没有完成

                                                        if(this.threads[i].getDownLength() == -1){//如果 下载失败,再重新下载

                                                                 RandomAccessFile randOut = new RandomAccessFile(this.saveFile, "rw");

                                                                 randOut.seek(this.data.get(i+1));

                                                                 this.threads[i] = new DownloadThread(this, this.url, randOut, this.block, this.data.get(i+1), i+1);

                                                                 this.threads[i].setPriority(7);

                                                                 this.threads[i].start();

                                                        }

                                               }

                                     }                                   

                                     if(listener!=null) listener.onDownloadSize(this.downloadSize);

                            }

                            fileService.delete(this.downloadUrl);

                   } catch (Exception e) {

                            print(e.toString());

                            throw new Exception("下载失败");

                   }

                   return this.downloadSize;

         }

         /**

          * 获取Http响 应头字段

          * @param http

          * @return

          */

         public static Map getHttpResponseHeader(HttpURLConnection http) {

                   Map header = new LinkedHashMap();

                   for (int i = 0;; i++) {

                            String mine = http.getHeaderField(i);

                            if (mine == null) break;

                            header.put(http.getHeaderFieldKey(i), mine);

                   }

                   return header;

         }

         /**

          * 打印Http头 字段

          * @param http

          */

         public static void printResponseHeader(HttpURLConnection http){

                   Map header = getHttpResponseHeader(http);

                   for(Map.Entry entry : header.entrySet()){

                            String key = entry.getKey()!=null ? entry.getKey()+ ":" : "";

                            print(key+ entry.getValue());

                   }

         }

 

         private static void print(String msg){

                   Log.i(TAG, msg);

         }

}

 

       7.DownloadProgressListener

package com.changcheng.net.download;

 

public interface DownloadProgressListener {

         public void onDownloadSize(int size);

}