FileInputStream如何获取File的内容？

Question

我有一个文件f,我需要将其影响到FileInputStream fs:

File f = new File("C:/dir/foo.txt");
FileInputStream fs = (FileInputStream)f;

但我得到这个错误:

Cannot cast from File to FileInputStream

怎么能fs得到的内容f？

Answer 1

诀窍是:

FileInputStream fs = new FileInputStream(f);