file和inputstream相互转换

File –> InputStream

InputStream in = new FileInputStream(file);

InputStream –> File

public void inputstreamtofile(InputStream ins,File file){ 
   
   OutputStream os = new FileOutputStream(file);
   int bytesRead = 0;
   byte[] buffer = new byte[8192];
   while ((bytesRead = ins.read(buffer, 0, 8192)) != -1) { 
   
     os.write(buffer, 0, bytesRead);
   }
   os.close();
   ins.close();
}