文件下载

DownloadService

//使用Service实现文件下载
public class NewDownloadService extends IntentService {

	public static final int UPDATE_PROGRESS = 8344;
	public static final String DOWNLOAD_DIR=Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getAbsolutePath()+"/";
	public NewDownloadService() {
		super("NewDownloadService");
	}

	@Override
	protected void onHandleIntent(Intent intent) {
		String urlToDownload = intent.getStringExtra("url");
		String fileName=intent.getStringExtra("file_name");
		ResultReceiver receiver = (ResultReceiver) intent
				.getParcelableExtra("receiver");
		try {
			URL url = new URL(urlToDownload);
			URLConnection connection = url.openConnection();
			connection.connect();
			// this will be useful so that you can show a typical 0-100%
			// progress bar
			int fileLength = connection.getContentLength();

			// download the file
			InputStream input = new BufferedInputStream(url.openStream());
			OutputStream output = new FileOutputStream(
					DOWNLOAD_DIR+fileName);

			byte data[] = new byte[1024];
			long total = 0;
			int count;
			while ((count = input.read(data)) != -1) {
				total += count;
				// publishing the progress....
				Bundle resultData = new Bundle();
				resultData.putInt("progress", (int) (total * 100 / fileLength));
				receiver.send(UPDATE_PROGRESS, resultData);
				output.write(data, 0, count);
			}

			output.flush();
			output.close();
			input.close();
		} catch (IOException e) {
			e.printStackTrace();
			Toast.makeText(getApplicationContext(), "下载失败", Toast.LENGTH_SHORT).show();
		}

		Bundle resultData = new Bundle();
		resultData.putInt("progress", 100);
		receiver.send(UPDATE_PROGRESS, resultData);
	}

}



//下载用的Activity
public class DownloadActivity extends QMBaseActivity{

	private ImageView mIvFileImg;
	private TextView mTvFileName;
	private ProgressBar mProgressBar;
	private Button mBtnOperaio;
	private String mFileName;
	private String mFileUrl;
	
	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		
	}

	@Override
	protected int setLayoutId() {
		return R.layout.activity_download;
	}

	@Override
	protected void fillData() {
		mTvFileName.setText(mFileName);
		
	}

	@Override
	protected void initTitleBarContent() {
		mTitleHelper.centerStr="附件下载";
		mTitleHelper.rightPic=0;
		
	}

	@Override
	protected void initView() {
		mIvFileImg=(ImageView) findViewById(R.id.download_iv_file_img);
		mTvFileName=(TextView) findViewById(R.id.download_tv_file_name);
		mProgressBar=(ProgressBar) findViewById(R.id.download_pb_status);
		mBtnOperaio=(Button) findViewById(R.id.download_btn_opreation);
		
		mFileName=getIntent().getStringExtra("file_name");
		mFileUrl=getIntent().getStringExtra("url");
	}

	@Override
	protected void regListener() {
		mBtnOperaio.setOnClickListener(this);
		Intent intent = new Intent(this, NewDownloadService.class);
		intent.putExtra("url", mFileUrl);
		intent.putExtra("file_name", mFileName);
		intent.putExtra("receiver", new DownloadReceiver(new Handler()));
		startService(intent);
	}

	//回调的广播
	private class DownloadReceiver extends ResultReceiver{
	    public DownloadReceiver(Handler handler) {
	        super(handler);
	    }

	    @Override
	    protected void onReceiveResult(int resultCode, Bundle resultData) {
	        super.onReceiveResult(resultCode, resultData);
	        if (resultCode == NewDownloadService.UPDATE_PROGRESS) {
	            int progress = resultData.getInt("progress");
	            mProgressBar.setProgress(progress);
	            if (progress == 100) {
	                mProgressBar.setVisibility(View.GONE);
	                mBtnOperaio.setVisibility(View.VISIBLE);
	                mBtnOperaio.setText("打开文件");
	            }
	        }
	    }
	}
}

DownloadTask

//使用AsyncTask实现文件下载
private class DownloadTask extends AsyncTask<String, Integer, String> {

		private Context context;
		private PowerManager.WakeLock mWakeLock;
		private ProgressBar progressBar;
		private Button btnOpreation;
		private GridItem item;
		private String filePath;

		public DownloadTask(Context context, GridItem item,
				ProgressBar progressBar, Button btn) {
			this.context = context;
			this.item = item;
			this.progressBar = progressBar;
			this.btnOpreation = btn;
		}

		@Override
		protected String doInBackground(String... sUrl) {
			InputStream input = null;
			OutputStream output = null;
			HttpURLConnection connection = null;
			try {
				URL url = new URL(sUrl[0]);
				connection = (HttpURLConnection) url.openConnection();
				connection.connect();

				// expect HTTP 200 OK, so we don't mistakenly save error report
				// instead of the file
				if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
					return "Server returned HTTP "
							+ connection.getResponseCode() + " "
							+ connection.getResponseMessage();
				}

				// this will be useful to display download percentage
				// might be -1: server did not report the length
				int fileLength = connection.getContentLength();

				// download the file
				input = connection.getInputStream();
				filePath = IMG_DOWNLOAD_DIR + MD5Util.getMD5(sUrl[0])
						+ IMG_EXTENSION;
				output = new FileOutputStream(filePath);
				byte data[] = new byte[4096];
				long total = 0;
				int count;
				while ((count = input.read(data)) != -1) {
					// allow canceling with back button
					if (isCancelled()) {
						input.close();
						return null;
					}
					total += count;
					// publishing the progress....
					if (fileLength > 0) // only if total length is known
						publishProgress((int) (total * 100 / fileLength));
					output.write(data, 0, count);
				}
			} catch (Exception e) {
				return e.toString();
			} finally {
				try {
					if (output != null)
						output.close();
					if (input != null)
						input.close();
				} catch (IOException ignored) {
				}

				if (connection != null)
					connection.disconnect();
			}
			return null;
		}

		@Override
		protected void onPreExecute() {
			super.onPreExecute();
			// take CPU lock to prevent CPU from going off if the user
			// presses the power button during download
			PowerManager pm = (PowerManager) context
					.getSystemService(Context.POWER_SERVICE);
			mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
					getClass().getName());
			mWakeLock.acquire();
			progressBar.setVisibility(View.VISIBLE);
		}

		@Override
		protected void onProgressUpdate(Integer... progress) {
			super.onProgressUpdate(progress);
			// if we get here, length is known, now set indeterminate to false
			progressBar.setIndeterminate(false);
			progressBar.setMax(100);
			progressBar.setProgress(progress[0]);
		}

		@Override
		protected void onPostExecute(String result) {
			mWakeLock.release();
			progressBar.setVisibility(View.GONE);
			progressBar.setProgress(0);
			if (result != null || isCancelled()) {
				Toast.makeText(context, "主题下载失败: " + result, Toast.LENGTH_LONG)
						.show();
			} else {
				Toast.makeText(context, "主题下载成功", Toast.LENGTH_SHORT).show();
				SharePerferenceControlor.setString(context, item.getTitle(),
						filePath);
				btnOpreation.setVisibility(View.INVISIBLE);
			}
		}
	}