Android下载封装类

public class Download implements Serializable {      private static final int START = 1;                 // 开始下载      private static final int PUBLISH = 2;               // 更新进度      private static final int PAUSE = 3;                 // 暂停下载      private static final int CANCEL = 4;                // 取消下载      private static final int ERROR = 5;                 // 下载错误      private static final int SUCCESS = 6;               // 下载成功      private static final int GOON = 7;                  // 继续下载             private static ExecutorService mThreadPool;         // 线程池             static {          mThreadPool = Executors.newFixedThreadPool(5);  // 默认5个       }                 private int mDownloadId;                            // 下载id      private String mFileName;                           // 本地保存文件名      private String mUrl;                                // 下载地址      private String mLocalPath;                          // 本地存放目录         private boolean isPause = false;                    // 是否暂停      private boolean isCanceled = false;                 // 是否手动停止下载             private OnDownloadListener mListener;               // 监听器             /**       * 配置下载线程池的大小       * @param maxSize 同时下载的最大线程数       */      public static void configDownloadTheadPool(int maxSize) {          mThreadPool = Executors.newFixedThreadPool(maxSize);      }             /**       * 添加下载任务       * @param downloadId 下载任务的id       * @param url        下载地址       * @param localPath   本地存放地址       */      public Download(int downloadId, String url, String localPath) {          if (!new File(localPath).exists()) {              new File(localPath).mkdirs();          }                     Log.log("下载地址；" + url);                     mDownloadId = downloadId;          mUrl = url;          String[] tempArray = url.split("/");          mFileName = tempArray[tempArray.length-1];          mLocalPath = localPath;      }             /**       * 设置监听器       * @param listener 设置下载监听器       * @return this       */      public Download setOnDownloadListener(OnDownloadListener listener) {          mListener = listener;          return this;      }             /**       * 获取文件名       * @return 文件名       */      public String getFileName() {          return mFileName;      }         /**       * 开始下载       * params isGoon是否为继续下载       */      public void start(final boolean isGoon) {          // 处理消息          final Handler handler = new Handler() {              @Override              public void handleMessage(Message msg) {                  switch (msg.what) {                  case ERROR:                      mListener.onError(mDownloadId);                      break;                  case CANCEL:                      mListener.onCancel(mDownloadId);                      break;                  case PAUSE:                      mListener.onPause(mDownloadId);                      break;                  case PUBLISH:                      mListener.onPublish(mDownloadId, Long.parseLong(msg.obj.toString()));                      break;                  case SUCCESS:                      mListener.onSuccess(mDownloadId);                      break;                  case START:                      mListener.onStart(mDownloadId, Long.parseLong(msg.obj.toString()));                      break;                  case GOON:                      mListener.onGoon(mDownloadId, Long.parseLong(msg.obj.toString()));                      break;                  }              }          };                     // 真正开始下载          mThreadPool.execute(new Runnable() {              @Override              public void run() {                  download(isGoon,handler);              }          });      }             /**       * 下载方法       * @param handler 消息处理器       */      private void download(boolean isGoon, Handler handler) {          Message msg = null;          Log.log("开始下载。。。");          try {              RandomAccessFile localFile = new RandomAccessFile(new File(                      mLocalPath + File.separator + mFileName), "rwd");                 DefaultHttpClient client = new DefaultHttpClient();              client.setParams(getHttpParams());              HttpGet get = new HttpGet(mUrl);                 long localFileLength = getLocalFileLength();              final long remoteFileLength = getRemoteFileLength();              long downloadedLength = localFileLength;                             // 远程文件不存在              if (remoteFileLength == -1l) {                  Log.log("下载文件不存在...");                  localFile.close();                  handler.sendEmptyMessage(ERROR);                  return;              }                 // 本地文件存在              if (localFileLength > -1l && localFileLength < remoteFileLength) {                  Log.log("本地文件存在...");                  localFile.seek(localFileLength);                  get.addHeader("Range", "bytes=" + localFileLength + "-"                          + remoteFileLength);              }                             msg = Message.obtain();                             // 如果不是继续下载              if(!isGoon) {                  // 发送开始下载的消息并获取文件大小的消息                  msg.what = START;                  msg.obj = remoteFileLength;              }else {                  msg.what = GOON;                  msg.obj = localFileLength;              }                             handler.sendMessage(msg);                             HttpResponse response = client.execute(get);              int httpCode = response.getStatusLine().getStatusCode();              if (httpCode >= 200 && httpCode <= 300) {                  InputStream in = response.getEntity().getContent();                  byte[] bytes = new byte[1024];                  int len = -1;                  while (-1 != (len = in.read(bytes))) {                      localFile.write(bytes, 0, len);                      downloadedLength += len;  //                  Log.log((int)(downloadedLength/(float)remoteFileLength * 100));                      if ((int)(downloadedLength/(float)remoteFileLength * 100) % 10 == 0) {                          // 发送更新进度的消息                          msg = Message.obtain();                          msg.what = PUBLISH;                          msg.obj = downloadedLength;                          handler.sendMessage(msg);  //                      Log.log(mDownloadId + "已下载" + downloadedLength);                      }                                             // 暂停下载， 退出方法                      if (isPause) {                          // 发送暂停的消息                          handler.sendEmptyMessage(PAUSE);                          Log.log("下载暂停...");                          break;                      }                                             // 取消下载， 删除文件并退出方法                      if (isCanceled) {                          Log.log("手动关闭下载。。");                          localFile.close();                          client.getConnectionManager().shutdown();                          new File(mLocalPath + File.separator + mFileName)                                  .delete();                          // 发送取消下载的消息                          handler.sendEmptyMessage(CANCEL);                          return;                      }                  }                     localFile.close();                  client.getConnectionManager().shutdown();                  // 发送下载完毕的消息                  if(!isPause) handler.sendEmptyMessage(SUCCESS);              }             } catch (Exception e) {              // 发送下载错误的消息              handler.sendEmptyMessage(ERROR);          }      }         /**       * 暂停/继续下载       * param pause 是否暂停下载       * 暂停 return true       * 继续 return false       */      public synchronized boolean pause(boolean pause) {          if(!pause) {              Log.log("继续下载");              isPause = false;              start(true); // 开始下载          }else {              Log.log("暂停下载");              isPause = true;          }          return isPause;      }         /**       * 关闭下载， 会删除文件       */      public synchronized void cancel() {          isCanceled = true;          if(isPause) {              new File(mLocalPath + File.separator + mFileName)              .delete();          }      }         /**       * 获取本地文件大小       * @return 本地文件的大小 or 不存在返回-1       */      public synchronized long getLocalFileLength() {          long size = -1l;          File localFile = new File(mLocalPath + File.separator + mFileName);          if (localFile.exists()) {              size = localFile.length();          }          Log.log("本地文件大小" + size);          return size <= 0 ? -1l : size;      }         /**       * 获取远程文件打下 or 不存在返回-1       * @return       */      public synchronized long getRemoteFileLength() {          long size = -1l;          try {              DefaultHttpClient client = new DefaultHttpClient();              client.setParams(getHttpParams());              HttpGet get = new HttpGet(mUrl);                 HttpResponse response = client.execute(get);              int httpCode = response.getStatusLine().getStatusCode();              if (httpCode >= 200 && httpCode <= 300) {                  size = response.getEntity().getContentLength();              }                 client.getConnectionManager().shutdown();          } catch (Exception e) {              e.printStackTrace();          }             Log.log("远程文件大小" + size);          return size;      }         /**       * 设置http参数 不能设置soTimeout       * @return HttpParams http参数       */      private static HttpParams getHttpParams() {          HttpParams params = new BasicHttpParams();             HttpProtocolParams.setContentCharset(params, HTTP.UTF_8);          HttpProtocolParams.setUseExpectContinue(params, true);          HttpProtocolParams                  .setUserAgent(                          params,                          "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2041.4 Safari/537.36");          ConnManagerParams.setTimeout(params, 4000);          HttpConnectionParams.setConnectionTimeout(params, 4000);                     return params;      }             /**       * 关闭下载线程池       */      public static void closeDownloadThread() {          if(null != mThreadPool) {              mThreadPool.shutdownNow();          }      }         public interface OnDownloadListener {          public void onStart(int downloadId, long fileSize);  // 回调开始下载          public void onPublish(int downloadId, long size);    // 回调更新进度          public void onSuccess(int downloadId);               // 回调下载成功          public void onPause(int downloadId);                 // 回调暂停          public void onError(int downloadId);                 // 回调下载出错          public void onCancel(int downloadId);                // 回调取消下载          public void onGoon(int downloadId, long localSize);  // 回调继续下载      }  }

如何调用，如下：

            Download d = new Download(1, "http://baidu.com/test.zip","/sdcard/download/");              d.setOnDownloadListener(new Download.OnDownloadListener() {                  @Override                  public void onSuccess(int downloadId) {                      System.out.println(downloadId + "下载成功");                  }                         @Override                  public void onStart(int downloadId, long fileSize) {                      System.out.println(downloadId + "开始下载，文件大小：" + fileSize);                  }                         @Override                  public void onPublish(int downloadId, long size) {                      System.out.println("更新文件" + downloadId + "大小：" + size);                  }                         @Override                  public void onPause(int downloadId) {                      System.out.println("暂停下载" + downloadId);                  }                         @Override                  public void onGoon(int downloadId, long localSize) {                      System.out.println("继续下载" + downloadId);                  }                         @Override                  public void onError(int downloadId) {                      System.out.println("下载出错" + downloadId);                  }                         @Override                  public void onCancel(int downloadId) {                      System.out.println("取消下载" + downloadId);                  }              });                     d.start(false);