try (BufferedInputStream bis = new BufferedInputStream(is);
             BufferedOutputStream bos = new BufferedOutputStream(
                     new FileOutputStream(file));) {
            byte[] buffer = new byte[1024];
            int len = -1;
            while ((len = bis.read(buffer)) != -1) {
                bos.write(buffer, 0, len);
                bos.flush();
            }
        } catch (IOException e) {
            e.printStackTrace();
}
 

這樣就夠了，但是以前得多個finally,並且對象定義還得放到try的前面：

BufferedInputStream bis =  null;
BufferedOutputStream bos = null;
try  {              
      bis = new BufferedInputStream(is);  
      bos = new BufferedOutputStream(new FileOutputStream(file));
      byte[] buffer = new byte[1024];
      int len = -1;
      while ((len = bis.read(buffer)) != -1) {
           bos.write(buffer, 0, len);
           bos.flush();
       }
} catch (IOException e) {
      e.printStackTrace();
}finally{
         if(null!=bis){
                    bis.close();
            }
            if(null!=bos){
                    bos.close();
        }
}
 

java中try-catch模塊中with語句塊的作用