【No2.】下载文件工具类

public class FileDownloadHelper {private static final String TAG = "FileDownloadHelper";/** 线程池 */private ThreadPool mPool = new ThreadPool();/** 开始下载 */public static final int MESSAGE_START = 0;/** 更新进度 */public static final int MESSAGE_PROGRESS = 1;/** 下载结束 */public static final int MESSAGE_STOP = 2;/** 下载出错 */public static final int MESSAGE_ERROR = 3;/** 中途终止 */private volatile boolean mIsStop = false;private Handler mHandler;public volatile HashMap<String, String> mDownloadUrls = new HashMap<String, String>();public FileDownloadHelper(Handler handler) {if (handler == null)throw new IllegalArgumentException("handler不能为空!");this.mHandler = handler;}public void stopALl() {mIsStop = true;mPool.stop();}/** * 下载一个新的文件 *  * @param url * @param savePath */public void newDownloadFile(final String url, final String savePath) {if (mDownloadUrls.containsKey(url))return;elsemDownloadUrls.put(url, savePath);mPool.start(new Runnable() {@Overridepublic void run() {mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_START, url));HttpClient client = new DefaultHttpClient();HttpGet get = new HttpGet(url);InputStream inputStream = null;FileOutputStream outputStream = null;try {HttpResponse response = client.execute(get);HttpEntity entity = response.getEntity();final int size = (int) entity.getContentLength();inputStream = entity.getContent();if (size > 0 && inputStream != null) {outputStream = new FileOutputStream(savePath);int ch = -1;byte[] buf = new byte[1024];// 每秒更新一次进度new Timer().schedule(new TimerTask() {@Overridepublic void run() {try {FileInputStream fis = new FileInputStream(new File(savePath));int downloadedSize = fis.available();if (downloadedSize >= size)cancel();mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_PROGRESS, downloadedSize, size, url));} catch (Exception e) {}}}, 50, 1000);while ((ch = inputStream.read(buf)) != -1 && !mIsStop) {outputStream.write(buf, 0, ch);}outputStream.flush();}} catch (Exception e) {Log.e(TAG, e.getMessage(), e);mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_ERROR,url + ":" + e.getMessage()));} finally {try {if (outputStream != null)outputStream.close();} catch (IOException ex) {}try {if (inputStream != null)inputStream.close();} catch (IOException ex) {}}mDownloadUrls.remove(url);mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_STOP, url));}});}}

 

 ThreadPool.java

package com.example.c.myutils;import java.util.concurrent.LinkedBlockingQueue;import java.util.concurrent.ThreadFactory;import java.util.concurrent.ThreadPoolExecutor;import java.util.concurrent.TimeUnit;import java.util.concurrent.atomic.AtomicBoolean;import java.util.concurrent.atomic.AtomicInteger;import android.os.Build;public class ThreadPool {private AtomicBoolean mStopped = new AtomicBoolean(Boolean.FALSE);private ThreadPoolExecutor mQueue;public ThreadPool() {if (Build.VERSION.SDK_INT > 8) {mQueue = new ThreadPoolExecutor(10, 10, 60, TimeUnit.SECONDS,new LinkedBlockingQueue<Runnable>(), sThreadFactory);mQueue.allowCoreThreadTimeOut(true);} else {mQueue = new ThreadPoolExecutor(2, 10, 60, TimeUnit.SECONDS,new LinkedBlockingQueue<Runnable>(), sThreadFactory);}}public void start(Runnable run) {mQueue.execute(run);}public void stop() {if (!mStopped.get()) {mQueue.shutdownNow();mStopped.set(Boolean.TRUE);}}private static final ThreadFactory sThreadFactory = new ThreadFactory() {private final AtomicInteger mCount = new AtomicInteger(1);@Overridepublic Thread newThread(Runnable r) {return new Thread(r, "ThreadPool #" + mCount.getAndIncrement());}};}

 

下面贴出用法：

private FileDownloadHelper mDownloadHelper;private MyHandler myHandler;/** *   * @Description:TODO  */private void XiaZaiWenJian() {// TODO Auto-generated method stubmyHandler = new MyHandler();mDownloadHelper = new FileDownloadHelper(myHandler);mDownloadHelper.newDownloadFile("http://172.16.2.137:8080/myweb/video/1.3gp", SPConstant.SDcard_PATH+"/"+"aa.3gp");}public class MyHandler extends Handler{/**  * Title: handleMessage * @Description: * @param msg  * @see android.os.Handler#handleMessage(android.os.Message)  */@Overridepublic void handleMessage(Message msg) {// TODO Auto-generated method stubsuper.handleMessage(msg);switch (msg.what) {case FileDownloadHelper.MESSAGE_START:LogUtile.d(TAG, "开始下载");break;case FileDownloadHelper.MESSAGE_PROGRESS:int dangQian = msg.arg1;int total = msg.arg2;if (dangQian < total) {LogUtile.d(TAG, "当前下载的进度"+dangQian+"文件总长度"+total);}break;case FileDownloadHelper.MESSAGE_STOP:LogUtile.d(TAG, "结束下载");break;case FileDownloadHelper.MESSAGE_ERROR:LogUtile.d(TAG, "下载出错");break;default:break;}}}