Android之多线程断点下载

本文主要包含多线程下载的一些简单demo,包括三部分

java实现
android实现
XUtils开源库实现

注意下载添加网络权限与SD卡读写权限

java实现多线程下载

public class MutileThreadDownload {/*** 线程的数量*/private static int threadCount = 3;/*** 每个下载区块的大小*/private static long blocksize;/*** 正在运行的线程的数量*/private static int runningThreadCount;/*** @param args* @throws Exception*/public static void main(String[] args) throws Exception {// 服务器文件的路径String path = "http://192.168.1.100:8080/ff.exe";URL url = new URL(path);HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");conn.setConnectTimeout(5000);int code = conn.getResponseCode();if (code == 200) {long size = conn.getContentLength();// 得到服务端返回的文件的大小System.out.println("服务器文件的大小：" + size);blocksize = size / threadCount;// 1.首先在本地创建一个大小跟服务器一模一样的空白文件。File file = new File("temp.exe");RandomAccessFile raf = new RandomAccessFile(file, "rw");raf.setLength(size);// 2.开启若干个子线程分别去下载对应的资源。runningThreadCount = threadCount;for (int i = 1; i <= threadCount; i++) {long startIndex = (i - 1) * blocksize;long endIndex = i * blocksize - 1;if (i == threadCount) {// 最后一个线程endIndex = size - 1;}System.out.println("开启线程：" + i + "下载的位置：" + startIndex + "~"+ endIndex);new DownloadThread(path, i, startIndex, endIndex).start();}}conn.disconnect();}private static class DownloadThread extends Thread {private int threadId;private long startIndex;private long endIndex;private String path;public DownloadThread(String path, int threadId, long startIndex,long endIndex) {this.path = path;this.threadId = threadId;this.startIndex = startIndex;this.endIndex = endIndex;}@Overridepublic void run() {try {// 当前线程下载的总大小int total = 0;File positionFile = new File(threadId + ".txt");URL url = new URL(path);HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");// 接着从上一次的位置继续下载数据if (positionFile.exists() && positionFile.length() > 0) {// 判断是否有记录FileInputStream fis = new FileInputStream(positionFile);BufferedReader br = new BufferedReader(new InputStreamReader(fis));// 获取当前线程上次下载的总大小是多少String lasttotalstr = br.readLine();int lastTotal = Integer.valueOf(lasttotalstr);System.out.println("上次线程" + threadId + "下载的总大小："+ lastTotal);startIndex += lastTotal;total += lastTotal;// 加上上次下载的总大小。fis.close();}conn.setRequestProperty("Range", "bytes=" + startIndex + "-"+ endIndex);conn.setConnectTimeout(5000);int code = conn.getResponseCode();System.out.println("code=" + code);InputStream is = conn.getInputStream();File file = new File("temp.exe");RandomAccessFile raf = new RandomAccessFile(file, "rw");// 指定文件开始写的位置。raf.seek(startIndex);System.out.println("第" + threadId + "个线程：写文件的开始位置："+ String.valueOf(startIndex));int len = 0;byte[] buffer = new byte[512];while ((len = is.read(buffer)) != -1) {RandomAccessFile rf = new RandomAccessFile(positionFile,"rwd");raf.write(buffer, 0, len);total += len;rf.write(String.valueOf(total).getBytes());rf.close();}is.close();raf.close();} catch (Exception e) {e.printStackTrace();} finally {// 只有所有的线程都下载完毕后 才可以删除记录文件。synchronized (MutileThreadDownload.class) {System.out.println("线程" + threadId + "下载完毕了");runningThreadCount--;if (runningThreadCount < 1) {System.out.println("所有的线程都工作完毕了。删除临时记录的文件");for (int i = 1; i <= threadCount; i++) {File f = new File(i + ".txt");System.out.println(f.delete());}}}}}}
}

安卓实现

public class MainActivity extends Activity {protected static final int DOWNLOAD_ERROR = 1;private static final int THREAD_ERROR = 2;public static final int DWONLOAD_FINISH = 3;private EditText et_path;private EditText et_count;/*** 存放进度条的布局*/private LinearLayout ll_container;/*** 进度条的集合*/private List<ProgressBar> pbs;/*** android下的消息处理器，在主线程创建，才可以更新ui*/private Handler handler = new Handler(){public void handleMessage(Message msg) {switch (msg.what) {case DOWNLOAD_ERROR:Toast.makeText(getApplicationContext(), "下载失败", 0).show();break;case THREAD_ERROR:Toast.makeText(getApplicationContext(), "下载失败,请重试", 0).show();break;case DWONLOAD_FINISH:Toast.makeText(getApplicationContext(), "下载完成", 0).show();break;}};};/*** 线程的数量*/private int threadCount = 3;/*** 每个下载区块的大小*/private long blocksize;/*** 正在运行的线程的数量*/private  int runningThreadCount;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);et_path = (EditText) findViewById(R.id.et_path);et_count = (EditText) findViewById(R.id.et_count);ll_container = (LinearLayout) findViewById(R.id.ll_container);}/*** 下载按钮的点击事件* @param view*/public void downLoad(View view){//下载文件的路径final String path = et_path.getText().toString().trim();if(TextUtils.isEmpty(path)){Toast.makeText(this, "对不起下载路径不能为空", 0).show();return;}String count = et_count.getText().toString().trim();if(TextUtils.isEmpty(path)){Toast.makeText(this, "对不起,线程数量不能为空", 0).show();return;}threadCount = Integer.parseInt(count);//清空掉旧的进度条ll_container.removeAllViews();//在界面里面添加count个进度条pbs = new ArrayList<ProgressBar>();for(int j=0;j<threadCount;j++){ProgressBar pb = (ProgressBar) View.inflate(this, R.layout.pb, null);ll_container.addView(pb);pbs.add(pb);}Toast.makeText(this, "开始下载", 0).show();new Thread(){public void run() {try {URL url = new URL(path);HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");conn.setConnectTimeout(5000);int code = conn.getResponseCode();if (code == 200) {long size = conn.getContentLength();// 得到服务端返回的文件的大小System.out.println("服务器文件的大小：" + size);blocksize = size / threadCount;// 1.首先在本地创建一个大小跟服务器一模一样的空白文件。File file = new File(Environment.getExternalStorageDirectory(),getFileName(path));RandomAccessFile raf = new RandomAccessFile(file, "rw");raf.setLength(size);// 2.开启若干个子线程分别去下载对应的资源。runningThreadCount = threadCount;for (int i = 1; i <= threadCount; i++) {long startIndex = (i - 1) * blocksize;long endIndex = i * blocksize - 1;if (i == threadCount) {// 最后一个线程endIndex = size - 1;}System.out.println("开启线程：" + i + "下载的位置：" + startIndex + "~"+ endIndex);int threadSize = (int) (endIndex - startIndex);pbs.get(i-1).setMax(threadSize);new DownloadThread(path, i, startIndex, endIndex).start();}}conn.disconnect();} catch (Exception e) {e.printStackTrace();Message msg = Message.obtain();msg.what = DOWNLOAD_ERROR;handler.sendMessage(msg);}};}.start();}private class DownloadThread extends Thread {private int threadId;private long startIndex;private long endIndex;private String path;public DownloadThread(String path, int threadId, long startIndex,long endIndex) {this.path = path;this.threadId = threadId;this.startIndex = startIndex;this.endIndex = endIndex;}@Overridepublic void run() {try {// 当前线程下载的总大小int total = 0;File positionFile = new File(Environment.getExternalStorageDirectory(),getFileName(path)+threadId + ".txt");URL url = new URL(path);HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");// 接着从上一次的位置继续下载数据if (positionFile.exists() && positionFile.length() > 0) {// 判断是否有记录FileInputStream fis = new FileInputStream(positionFile);BufferedReader br = new BufferedReader(new InputStreamReader(fis));// 获取当前线程上次下载的总大小是多少String lasttotalstr = br.readLine();int lastTotal = Integer.valueOf(lasttotalstr);System.out.println("上次线程" + threadId + "下载的总大小："+ lastTotal);startIndex += lastTotal;total += lastTotal;// 加上上次下载的总大小。fis.close();//存数据库。//_id path threadid total}conn.setRequestProperty("Range", "bytes=" + startIndex + "-"+ endIndex);conn.setConnectTimeout(5000);int code = conn.getResponseCode();System.out.println("code=" + code);InputStream is = conn.getInputStream();File file = new File(Environment.getExternalStorageDirectory(),getFileName(path));RandomAccessFile raf = new RandomAccessFile(file, "rw");// 指定文件开始写的位置。raf.seek(startIndex);System.out.println("第" + threadId + "个线程：写文件的开始位置："+ String.valueOf(startIndex));int len = 0;byte[] buffer = new byte[1024];while ((len = is.read(buffer)) != -1) {RandomAccessFile rf = new RandomAccessFile(positionFile,"rwd");raf.write(buffer, 0, len);total += len;rf.write(String.valueOf(total).getBytes());rf.close();pbs.get(threadId-1).setProgress(total);}is.close();raf.close();} catch (Exception e) {e.printStackTrace();Message msg = Message.obtain();msg.what = THREAD_ERROR;handler.sendMessage(msg);} finally {// 只有所有的线程都下载完毕后 才可以删除记录文件。synchronized (MainActivity.class) {System.out.println("线程" + threadId + "下载完毕了");runningThreadCount--;if (runningThreadCount < 1) {System.out.println("所有的线程都工作完毕了。删除临时记录的文件");for (int i = 1; i <= threadCount; i++) {File f = new File(Environment.getExternalStorageDirectory(),getFileName(path)+ i + ".txt");System.out.println(f.delete());}Message msg = Message.obtain();msg.what = DWONLOAD_FINISH;handler.sendMessage(msg);}}}}}//http://192.168.1.100:8080/aa.exeprivate String getFileName(String path){int start = path.lastIndexOf("/")+1;return path.substring(start);}}

利用XUtils开源框架实现，需要XUtils的jar包

public class MainActivity extends Activity {private EditText et_path;private TextView tv_info;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);et_path = (EditText) findViewById(R.id.et_path);tv_info = (TextView) findViewById(R.id.tv_info);}public void download(View view){String path = et_path.getText().toString().trim();if(TextUtils.isEmpty(path)){Toast.makeText(this, "请输入下载的路径", 0).show();return;}else{HttpUtils http = new HttpUtils();HttpHandler handler = http.download(path,"/sdcard/xxx.zip",true, // 如果目标文件存在，接着未完成的部分继续下载。服务器不支持RANGE时将从新下载。true, // 如果从请求返回信息中获取到文件名，下载完成后自动重命名。new RequestCallBack<File>() {@Overridepublic void onStart() {tv_info.setText("conn...");}@Overridepublic void onLoading(long total, long current, boolean isUploading) {tv_info.setText(current + "/" + total);}@Overridepublic void onSuccess(ResponseInfo<File> responseInfo) {tv_info.setText("downloaded:" + responseInfo.result.getPath());}@Overridepublic void onFailure(HttpException error, String msg) {tv_info.setText(msg);}});}}
}

完成

Android之多线程断点下载相关推荐

android学习笔记---31_多线程断点下载器,下载原理实现
1.1.31_多线程断点下载器 ----------------------- 1.软件界面: 文件下载路径 text框 button 下载点击后,下面显示下载 ...
android 多线程断点下载，listview 模式开始暂停等功能
android 多线程断点下载,listview 模式代码依次如下: 布局: <?xml version="1.0" encoding="utf-8"? ...
即拿即用-Android多线程断点下载
线程下载只需要确定好下载一个文件需要多少个线程,一般来说最好为3条线程,因为线程过多会占用系统资源,而且线程间的相互竞争也会导致下载变慢. 其次下载的时候将文件分割为三份(假设用3条线程下载)下载,在 ...
安卓客户端的多线程断点下载（SharedPreferences版）
题记:从百度百科上面我们知道,SharedPreferences是不支持多线程的,但是这次使用SharedPreferences实现了多线程断点下载.点解? 服务器端: 使用的是tomcat服务器,在 ...
iOS开发网络篇—多线程断点下载
iOS开发网络篇-多线程断点下载说明:本文介绍多线程断点下载.项目中使用了苹果自带的类,实现了同时开启多条线程下载一个较大的文件.因为实现过程较为复杂,所以下面贴出完整的代码. 实现思路:下载开始, ...
Java多线程断点下载
多线程下载已经提高了下载的效率,但是当一些特殊情况发生的时候,我们需要对程序进行处理,这样效率会更高.比如,断电断网等造成下载中断,那么我们下一次又要重新开始下载,这样效率底下,所以我们可以考虑使用断 ...
Android 多线程断点下载demo实现
先来一张效果图: 主要实现思路: 每一个下载都是通过RandomAccessFile对下载资源的总长进行切割之后,根据我们设置的线程多少进行计算之后开启多线程下载的.而每一个任务都是一个AsyncTa ...
Android多线程断点下载
到华为后,信息管理特别严格,文件不能外发.所以好久都没写博客了,今天周日,老婆非要我学习.就闲来无事,写一篇博客,呵呵-- 前段时间,项目中提到了断点下载apk并静默安装的需求.本打算用应用市场成熟的 ...
Android（java）学习笔记158：多线程断点下载的原理（JavaSE实现）
1. 为什么需要多线程下载? 服务器的资源有限,同时的平均地分配给每个客户端.开启的线程越多抢占的服务的资源就越多,下载的速度就越块. 2. 下载速度的限制条件? (1)你的电脑手机宽带的带宽 ...

Android之多线程断点下载

本文主要包含多线程下载的一些简单demo,包括三部分

注意下载添加网络权限与SD卡读写权限

java实现多线程下载

安卓实现

利用XUtils开源框架实现，需要XUtils的jar包

完成

Android之多线程断点下载相关推荐

最新文章

热门文章