Second

src/crypto/Crypto.java

@@ -1,10 +1,84 @@
 package crypto;
-
 import java.util.Scanner;
-
+import java.io.*;
 public class Crypto {
+    private static void encryption(String message, int key, String out) {
+        char let;
+        char let2;
+        StringBuilder str = new StringBuilder(message);
+        for (int i=0; i<str.length(); i++){
+            let = str.charAt(i);
+            let2=(char)(let+key);
+            str.setCharAt(i, let2);}
+        if (out.length()>0){
+            File file = new File(out);
+           try(FileWriter writer = new FileWriter(file)){
+               writer.write(str.toString());
+           } catch (IOException e){
+               System.out.println("The file can not be opened: " + out);
+           }
+
+        }
+        else  System.out.println(str);
+    }
+    private static void decryption(String message, int key, String out) {
+        char let;
+        char let2;
+        StringBuilder str = new StringBuilder(message);
+        for (int i=0; i<str.length(); i++){
+            let = str.charAt(i);
+            let2=(char)(let-key);
+            str.setCharAt(i, let2);}
+        if (out.length()>0){
+            File file = new File(out);
+            try(FileWriter writer = new FileWriter(file)){
+                writer.write(str.toString());
+            } catch (IOException e){
+                System.out.println("The file can not be opened: " + out);
+            }
+
+        }
+        else  System.out.println(str);
+    }
+
     public static void main(String[] args) {
-        Scanner scanner = new Scanner(System.in);
-	// write your code here
+        Scanner scan = new Scanner(System.in);
+        String message="", target;
+        int key;
+        int kostil=0;
+        String out="";
+        int indTarget=-1, indMessage=-1, indKey=-1, indIn=-1, indOut=-1;
+        for (int i=0; i<args.length; i++){
+            if(args[i].equals("-mode")) indTarget=i;
+            if(args[i].equals("-key")) indKey=i;
+            if(args[i].equals("-data")) indMessage=i;
+            if(args[i].equals("-in")) indIn=i;
+            if(args[i].equals("-out")) indOut=i;
+        }
+
+        if(indTarget>=0) target=args[indTarget+1];
+        else target="enc";
+        if (indKey>=0) key=Integer.valueOf(args[indKey+1]);
+        else key = scan.nextInt();
+
+         if (indIn>=0) {
+            File in = new File(args[indIn+1]);
+            try(Scanner scanner = new Scanner(in)){
+                message = scanner.nextLine();
+            } catch (FileNotFoundException e){
+                System.out.println("File is not found: " + in);
+                message=scan.nextLine();
+            }
+        }
+        if (message.length()>0) kostil++;
+        else if (indMessage >=0 ) message = args[indMessage+1];
+         else message=scan.nextLine();
+        if (indOut>=0) {
+            out =args[indOut+1];
+        }
+        System.out.println(out);
+        if (target.equals("enc") || target.equals("")) encryption(message, key, out);
+        else decryption(message, key, out);
+
     }
-}
+}