要求2什么意思
package zh.codegym.task.task18.task1814;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
/*
UnsupportedFileName
*/
public class TxtInputStream extends FileInputStream {
private FileInputStream fis;
public TxtInputStream(String fileName) throws Exception {
super(fileName);
fis = new FileInputStream(fileName);
if (!fileName.substring(fileName.length()-5).equals(".txt")){
super.close();
fis.close();
throw new UnsupportedFileNameException();
}
}
public static void main(String[] args) {
}
public void close() throws IOException{
fis.close();
}
}