![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
阅读下段代码 import java.io.*;public class Example{ public static void main(String[] args) throws Exception { FileInputStream fis = new FileInputStream("file.txt"); FileOutputStream fos = new FileOutputStream("copy_file.txt"); int ch = 0; while((ch =fis.read())!=-1){ fos.write(ch); } fos._______; fis.close(); }}请说出下划线上,填写的方法名称( )