android连接服务器下载文件工具类，android工具类, public s

android连接服务器下载文件工具类，android工具类, public s

    public static File downLoad(String serverPath,String savedPath,ProgressDialog dialog){              try {                  URL url=new URL(serverPath);                  HttpURLConnection _conn=(HttpURLConnection) url.openConnection();                  _conn.setRequestMethod("GET");                  _conn.setConnectTimeout(5000);                  int code=_conn.getResponseCode();                  if(code==200){                      //设置进度条的长度                      dialog.setMax(_conn.getContentLength());                      InputStream is=_conn.getInputStream();                      File _file=new File(savedPath);                      FileOutputStream _FileOutputStream=new FileOutputStream(_file);                      int len=0;                      byte[] buffer= new byte[1024];                      int _total=0;                      while((len=is.read(buffer))!=-1){                          _FileOutputStream.write(buffer, 0,len);                          _total+=len;                          dialog.setProgress(_total);                          Thread.sleep(20);                      }                      _FileOutputStream.flush();                      _FileOutputStream.close();                      is.close();                      return _file;                  }else {                      return null;                  }              } catch (Exception e) {                  // TODO Auto-generated catch block                  e.printStackTrace();                  return null;              }          }