Завис на данном задании.
Помогите понять
package com.javarush.task.task18.task1826;
/*
Шифровка
*/
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class Solution {
public static void main(String[] args) throws IOException {
switch (args[0]){
case "-e":
FileInputStream fileInputStream = new FileInputStream(args[1]);
FileOutputStream fileOutputStream = new FileOutputStream(args[2]);
while (fileInputStream.available() > 0){ ;
fileOutputStream.write(fileInputStream .read()- 1);
}
fileInputStream.close();
fileOutputStream.close();
case "-d":
FileInputStream fileInputStream1 = new FileInputStream(args[1]);
FileOutputStream fileOutputStream1 = new FileOutputStream(args[2]);
while (fileInputStream1.available() > 0){
fileOutputStream1.write(fileInputStream1.read() + 1);
}
fileInputStream1.close();
fileOutputStream1.close();
}
}
}