Android文件下载功能实现代码

public static void downLoad(String path,Context context)throws Exception
{
 URL url = new URL(path);
 InputStream is = url.openStream();
 //截取最后的文件名
 String end = path.substring(path.lastIndexOf("."));
 //打开手机对应的输出流,输出到文件中
 OutputStream os = context.openFileOutput("Cache_"+System.currentTimeMillis()+end, Context.MODE_PRIVATE);
 byte[] buffer = new byte[1024];
 int len = 0;
 //从输入六中读取数据,读到缓冲区中
 while((len = is.read(buffer)) > 0)
 {
  os.write(buffer,0,len);
 }
 //关闭输入输出流
 is.close();
 os.close();
}

public class Downloader {
 //添加@Test标记是表示该方法是Junit测试的方法,就可以直接运行该方法了
  @Test
  public void download() throws Exception
  {
   //设置URL的地址和下载后的文件名
   String filename = "meitu.exe";
   String path = "http://10.13.20.32:8080/Test/XiuXiu_Green.exe";
   URL url = new URL(path);
   HttpURLConnection cOnn= (HttpURLConnection) url.openConnection();
   conn.setConnectTimeout(5000);
   conn.setRequestMethod("GET");
   //获得需要下载的文件的长度(大小)
   int filelength = conn.getContentLength();
   System.out.println("要下载的文件长度"+filelength);
   //生成一个大小相同的本地文件
   RandomAccessFile file = new RandomAccessFile(filename, "rwd");
   file.setLength(filelength);
   file.close();
   conn.disconnect();
   //设置有多少条线程下载
   int threadsize = 3;
   //计算每个线程下载的量
   int threadlength = filelength % 3 == 0 &＃63; filelength/3:filelength+1;
   for(int i = 0;i