断点续传
来源：互联网 发布：淘宝女装图片素材 编辑：程序博客网 时间：2024/06/05 08:40
public class MainActivity extends AppCompatActivity { protected static final String TAG = "MainActivity"; //下载线程的数量 private final static int threadsize = 3; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void download(View v) { new Thread() { public void run() { try { //创建HttpClient对象 HttpClient client = new DefaultHttpClient();// http://c.hiphotos.baidu.com/image/pic/item/b90e7bec54e736d1e51217c292504fc2d46269f3.jpg// https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1495040157701&di// =e75c9d745a6af178d07e3e3b78e3cb3b&imgtype=0&src=http%3A%2F%2Fimg.pconline.com// .cn%2Fimages%2Fupload%2Fupc%2Ftx%2Fwallpaper%2F1502%2F03%2Fc0%2F2703334_1422958313278_800x600.jpg // String ur="http://c.hiphotos.baidu // .com/image/pic/item/b90e7bec54e736d1e51217c292504fc2d46269f3.jpg"; String uri = "http://video.jiecao.fm/5/1/%E8%87%AA%E5%8F%96%E5%85%B6%E8%BE%B1.mp4"; //从头信息里获取文件大小 不获取内容 HttpHead request = new HttpHead(uri); HttpResponse response = client.execute(request); //response 只有响应头 没有响应体 if (response.getStatusLine().getStatusCode() == 200) { //从响应头里获取长度 Header[] headers = response.getHeaders("Content-Length"); String value = headers[0].getValue(); //一 获取服务器上文件的大小 int filelength = Integer.parseInt(value); Log.i(TAG, "filelength:" + filelength); //二 在sdcard创建和服务器大小一样的文件 String name = getFileName(uri); File file = new File(Environment.getExternalStorageDirectory(), name); //随机访问文件 RandomAccessFile raf = new RandomAccessFile(file, "rwd"); //设置文件的大小 raf.setLength(filelength); //关闭 raf.close(); //计算每条线程的下载量 int block = (filelength % threadsize == 0) ? (filelength / threadsize) : (filelength / threadsize + 1); //开启三条线程执行下载 for (int threadid = 0; threadid < threadsize; threadid++) { new DownloadThread(threadid, uri, file, block).start(); } } } catch (Exception e) { e.printStackTrace(); } } ; }.start(); } //线程下载类 private class DownloadThread extends Thread { private int threadid;//线程的id private String uri;//下载的地址 private File file;//下载文件 private int block;//下载的块 private int start; private int end; public DownloadThread(int threadid, String uri, File file, int block) { super(); this.threadid = threadid; this.uri = uri; this.file = file; this.block = block; //计算下载的开始位置和结束位置 start = threadid * block; end = (threadid + 1) * block - 1; } //下载 状态码：200是普通的下载 206是分段下载 Range:范围 @Override public void run() { super.run(); try { RandomAccessFile raf = new RandomAccessFile(file, "rwd"); //跳转到起始位置 raf.seek(start); //分段下载真实内容 HttpClient client = new DefaultHttpClient(); HttpGet request = new HttpGet(uri); request.addHeader("Range", "bytes:" + start + "-" + end);//添加请求头 HttpResponse response = client.execute(request); if (response.getStatusLine().getStatusCode() == 200) { InputStream inputStream = response.getEntity().getContent(); //把流写入到文件 byte[] buffer = new byte[1024]; int len = 0; while ((len = inputStream.read(buffer)) != -1) { //写数据 raf.write(buffer, 0, len); } inputStream.close(); raf.close(); Log.i(TAG, "第" + threadid + "条线程下载完成"); } } catch (Exception e) { e.printStackTrace(); } } } private String getFileName(String uri) { return uri.substring(uri.lastIndexOf("/") + 1); }}activity_main
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:gravity="center_horizontal" tools:context="com.zhifei.test.duoxiancheng.MainActivity"> <TextView android:id="@+id/tv_path" android:text="多线程下载地址" android:layout_width="match_parent" android:layout_marginTop="50dp" android:layout_height="wrap_content"/> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="download" android:text="下载" /></LinearLayout>public class OtherActivity extends AppCompatActivity { protected static final String TAG = "OtherActivity"; //下载线程的数量 private final static int threadsize = 3; protected static final int SET_MAX = 0; public static final int UPDATE_VIEW = 1; private ProgressBar pb; private Button bt_download; private Button bt_pause; private TextView tv_info; //显示进度和更新进度 private Handler mHandler = new Handler(){ public void handleMessage(Message msg) { switch (msg.what) { case SET_MAX://设置进度条的最大值 int filelength = msg.arg1; pb.setMax(filelength); break; case UPDATE_VIEW://更新进度条 和 下载的比率 int len = msg.arg1;//新下载的长度 pb.setProgress(pb.getProgress()+len);//设置进度条的刻度 int max = pb.getMax();//获取进度的最大值 int progress = pb.getProgress();//获取已经下载的数据量 // 下载：30 总：100 int result = (progress*100)/max; tv_info.setText("下载:"+result+"%"); break; default: break; } }; }; String uri = "http://video.jiecao.fm/5/1/%E8%87%AA%E5%8F%96%E5%85%B6%E8%BE%B1.mp4"; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_other);//找到控件 pb = (ProgressBar) findViewById(R.id.pb); tv_info = (TextView) findViewById(R.id.tv_info); bt_download = (Button) findViewById(R.id.bt_download); bt_pause = (Button) findViewById(R.id.bt_pause); //数据的回显 //确定下载的文件 String name = getFileName(uri); File file = new File(Environment.getExternalStorageDirectory(), name); if (file.exists()){//文件存在回显 //获取文件的大小 int filelength = (int) file.length(); pb.setMax(filelength); try { //统计原来所有的下载量 int count = 0; //读取下载记录文件 for (int threadid = 0; threadid < threadsize; threadid++) { //获取原来指定线程的下载记录 int existDownloadLength = readDownloadInfo(threadid); count = count + existDownloadLength; } //设置进度条的刻度 pb.setProgress(count); //计算比率 int result = (count * 100) / filelength; tv_info.setText("下载:" + result + "%"); } catch (Exception e) { e.printStackTrace(); } } } //暂停 private boolean flag = false;//是否在下载 public void pause(View v){ flag = false; bt_download.setEnabled(true); bt_pause.setEnabled(false); }//下载 public void download(View v){ flag = true; bt_download.setEnabled(false); bt_pause.setEnabled(true); new Thread(){//子线程 public void run() { try { //获取服务器上文件的大小 HttpClient client = new DefaultHttpClient(); HttpHead request = new HttpHead(uri); HttpResponse response = client.execute(request); //response 只有响应头 没有响应体 if(response.getStatusLine().getStatusCode() == 200){ Header[] headers = response.getHeaders("Content-Length"); String value = headers[0].getValue(); //文件大小 int filelength = Integer.parseInt(value); Log.i(TAG, "filelength:"+filelength); //设置进度条的最大值 Message msg_setmax = Message.obtain(mHandler, SET_MAX, filelength, 0); msg_setmax.sendToTarget(); //处理下载记录文件 for(int threadid=0;threadid<threadsize;threadid++){ //对应的下载记录文件 File file = new File(Environment.getExternalStorageDirectory(),threadid+".mp4"); //判断文件是否存在 if(!file.exists()){ //创建文件 file.createNewFile(); } } //在sdcard创建和服务器大小一样的文件 String name = getFileName(uri); File file = new File(Environment.getExternalStorageDirectory(),name); //随机访问文件 RandomAccessFile raf = new RandomAccessFile(file, "rwd"); //设置文件的大小 raf.setLength(filelength); //关闭 raf.close(); //计算每条线程的下载量 int block = (filelength%threadsize == 0)?(filelength/threadsize):(filelength/threadsize+1); //开启三条线程执行下载 for(int threadid=0;threadid<threadsize;threadid++){ new DownloadThread(threadid, uri, file, block).start(); } } } catch (Exception e) { e.printStackTrace(); } }; }.start(); } //线程下载类 private class DownloadThread extends Thread{ private int threadid;//线程的id private String uri;//下载的地址 private File file;//下载文件 private int block;//下载的块 private int start; private int end; public DownloadThread(int threadid, String uri, File file, int block) { super(); this.threadid = threadid; this.uri = uri; this.file = file; this.block = block; //计算下载的开始位置和结束位置 start = threadid * block; end = (threadid + 1)*block -1; try { //读取该条线程原来的下载记录 int existDownloadLength = readDownloadInfo(threadid); //修改下载的开始位置 start = start + existDownloadLength; } catch (Exception e) { e.printStackTrace(); } } //下载 状态码：200是普通的下载 206是分段下载 Range:范围 @Override public void run() { super.run(); try { RandomAccessFile raf = new RandomAccessFile(file, "rwd"); //跳转到起始位置 raf.seek(start); //分段下载 HttpClient client = new DefaultHttpClient(); HttpGet request = new HttpGet(uri); request.addHeader("Range", "bytes:"+start+"-"+end);//添加请求头 HttpResponse response = client.execute(request); if(response.getStatusLine().getStatusCode() == 200){ InputStream inputStream = response.getEntity().getContent(); //把流写入到文件 byte[] buffer = new byte[1024]; int len = 0; while((len = inputStream.read(buffer)) != -1){ //如果暂停下载 就直接return if(!flag){ return;//标准线程结束 } //写数据 raf.write(buffer, 0, len); //读取原来下载的数据量 int existDownloadLength = readDownloadInfo(threadid);//原来下载的数据量 //计算最新的下载 int newDownloadLength = existDownloadLength + len; //更新下载记录 updateDownloadInfo(threadid, newDownloadLength); //更新进度条的显示 下载的百分比 Message update_msg = Message.obtain(mHandler, UPDATE_VIEW, len, 0); update_msg.sendToTarget(); //模拟 看到进度条动的效果 SystemClock.sleep(50); } inputStream.close(); raf.close(); Log.i(TAG, "第"+threadid+"条线程下载完成"); } } catch (Exception e) { e.printStackTrace(); } } } /** * 读取指定线程的下载数据量 * @param threadid 线程的id * @return * @throws Exception */ public int readDownloadInfo(int threadid) throws Exception{ //下载记录文件 File file = new File(Environment.getExternalStorageDirectory(),threadid+".mp4"); BufferedReader br = new BufferedReader(new FileReader(file)); //读取一行数据 String content = br.readLine(); int downlength = 0; //如果该文件第一次创建去执行读取操作 文件里面的内容是 null if(!TextUtils.isEmpty(content)){ downlength = Integer.parseInt(content); } //关闭流 br.close(); return downlength; } /** * 更新下载记录 * @param threadid * @param newDownloadLength */ public void updateDownloadInfo(int threadid,int newDownloadLength) throws Exception{ //下载记录文件 File file = new File(Environment.getExternalStorageDirectory(),threadid+".mp4"); FileWriter fw = new FileWriter(file); fw.write(newDownloadLength+""); fw.close(); } /** * 获取文件的名称 * @param uri * @return */ private String getFileName(String uri){ return uri.substring(uri.lastIndexOf("/")+1); }}activity_other
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="下载地址"/> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <Button android:id="@+id/bt_download" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="download" android:text="下载"/> <Button android:id="@+id/bt_pause" android:layout_width="wrap_content" android:layout_height="wrap_content" android:enabled="false" android:onClick="pause" android:text="暂停"/> </LinearLayout> <ProgressBar android:id="@+id/pb" style="@android:style/Widget.ProgressBar.Horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content"/> <TextView android:id="@+id/tv_info" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center" android:text="下载:0%"/></LinearLayout>依赖
compile 'com.loopj.android:android-async-http:1.4.9'权限
<uses-permission android:name="android.permission.INTERNET"></uses-permission><uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>代码有很多问题，发现后欢迎修改，这里提供个思路
废话不多说，看效果图
阅读全文
1 0
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 断点续传
- 活动报名:12月9号下午深圳Linuxer聚会下午茶交流
- JS实现点击下拉菜单把选择的内容同步到input输入框内
- spring+websocket的整合实例(超详细，可使用)
- Commit failed with error SVN:"xxx.x" is scheduled for addition, but is missing
- HTML5 <template>标签元素简介
- 断点续传
- 大龄转行IT,记录一下走过路过的坑，希望能对后来人有所帮助
- mybatis入门教程
- 说说css中pt、px、em、rem都扮演了什么角色
- 连接Java和C/C++层的关键--Android的JNI
- 【Scikit-Learn 中文文档】支持向量机
- ASP.NET MVC
- FeUdal Networks for Hierarchical Reinforcement Learning 阅读笔记
- JAVA虚拟机、Dalvik虚拟机和ART虚拟机简要对比
