refactor: create TranslationDictionary

Author: vbetsch

src/main/java/io/github/vbetsch/codecracker/Cypher.java

@@ -6,48 +6,13 @@
 import static java.util.Map.entry;
 
 public class Cypher {
-    private final Map<Character, Character> dictionary = Map.ofEntries(
-            entry('a', '!'),
-            entry('b', ')'),
-            entry('c', '"'),
-            entry('d', '('),
-            entry('e', '£'),
-            entry('f', '*'),
-            entry('g', '%'),
-            entry('h', '&'),
-            entry('i', '>'),
-            entry('j', '<'),
-            entry('k', '@'),
-            entry('l', 'a'),
-            entry('m', 'b'),
-            entry('n', 'c'),
-            entry('o', 'd'),
-            entry('p', 'e'),
-            entry('q', 'f'),
-            entry('r', 'g'),
-            entry('s', 'h'),
-            entry('t', 'i'),
-            entry('u', 'j'),
-            entry('v', 'k'),
-            entry('w', 'l'),
-            entry('x', 'm'),
-            entry('y', 'n'),
-            entry('z', 'o')
-    );
-
-    private static Map<Character, Character> invertMap(Map<Character, Character> map) {
-        Map<Character, Character> inverted = new HashMap<>();
-        for (Map.Entry<Character, Character> entry : map.entrySet()) {
-            inverted.put(entry.getValue(), entry.getKey());
-        }
-        return inverted;
-    }
+    private final TranslationDictionary dictionary = new TranslationDictionary();
 
     public char decryptLetter(char letter) {
-        return dictionary.get(letter);
+        return dictionary.getDecryptions().get(letter);
     }
 
     public char encryptChar(char character) {
-        return invertMap(dictionary).get(character);
+        return dictionary.getEncryptions().get(character);
     }
 }

src/main/java/io/github/vbetsch/codecracker/TranslationDictionary.java

@@ -0,0 +1,56 @@
+package io.github.vbetsch.codecracker;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static java.util.Map.entry;
+
+public class TranslationDictionary {
+
+    private final Map<Character, Character> decryptions = Map.ofEntries(
+            entry('a', '!'),
+            entry('b', ')'),
+            entry('c', '"'),
+            entry('d', '('),
+            entry('e', '£'),
+            entry('f', '*'),
+            entry('g', '%'),
+            entry('h', '&'),
+            entry('i', '>'),
+            entry('j', '<'),
+            entry('k', '@'),
+            entry('l', 'a'),
+            entry('m', 'b'),
+            entry('n', 'c'),
+            entry('o', 'd'),
+            entry('p', 'e'),
+            entry('q', 'f'),
+            entry('r', 'g'),
+            entry('s', 'h'),
+            entry('t', 'i'),
+            entry('u', 'j'),
+            entry('v', 'k'),
+            entry('w', 'l'),
+            entry('x', 'm'),
+            entry('y', 'n'),
+            entry('z', 'o')
+    );
+
+    private final Map<Character, Character> encryptions = invert(decryptions);
+
+    public Map<Character, Character> getDecryptions() {
+        return decryptions;
+    }
+
+    public Map<Character, Character> getEncryptions() {
+        return encryptions;
+    }
+
+    private static Map<Character, Character> invert(Map<Character, Character> map) {
+        Map<Character, Character> inverted = new HashMap<>();
+        for (Map.Entry<Character, Character> entry : map.entrySet()) {
+            inverted.put(entry.getValue(), entry.getKey());
+        }
+        return inverted;
+    }
+}