Complete

Crypto/src/ROT13.java

@@ -1,32 +1,73 @@
+package src
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.Scanner;
+
 import static java.lang.Character.isLowerCase;
 import static java.lang.Character.isUpperCase;
 import static java.lang.Character.toLowerCase;
 
 public class ROT13  {
-
+    private int shift;
     ROT13(Character cs, Character cf) {
+        this.shift = cs - cf;
     }
 
     ROT13() {
+        shift = 13;
     }
 
 
-    public String crypt(String text) throws UnsupportedOperationException {
-
-        return "";
+    public static String crypt(String text) throws UnsupportedOperationException {
+        StringBuilder sb = new StringBuilder();
+        char [] chars = text.toCharArray();
+        for (int i = 0; i <chars.length ; i++) {
+            char c = text.charAt(i);
+            if(c >= 'a' && c <= 'm') {
+                c += 13;
+            }else if  (c >= 'A' && c <= 'M') {
+                c += 13;
+            } else if  (c >= 'n' && c <= 'z') {
+                c -= 13;
+            } else if  (c >= 'N' && c <= 'Z') {
+                c -= 13;
+            }
+            sb.append(c);
+        }
+        return sb.toString();
     }
 
-    public String encrypt(String text) {
-        return text;
+    public static String encrypt(String text) {
+        return crypt(text);
     }
 
     public String decrypt(String text) {
-        return text;
+        return crypt(text);
     }
 
     public static String rotate(String s, Character c) {
+        //this method will rotate the given String
+        //by the character placement
+        String sub = s.substring(0,s.indexOf(c));
+        String sub1 = s.substring(s.indexOf(c));
+        //then concat the two substrings.
+        return sub1.concat(sub);
+    }
+    public static String textFile(String filename){
+        StringBuilder sb = new StringBuilder();
 
-        return "";
+        File file = new File(filename);
+        try(Scanner sc = new Scanner(file)) {
+            while(sc.hasNextLine()){
+                String line = sc.nextLine();
+                String xored = encrypt(line);
+                sb.append(xored+"\n");
+            }
+            sb.deleteCharAt(sb.length()-1);
+        } catch (FileNotFoundException e){
+            e.printStackTrace();
+        }
+        return sb.toString();
     }
 
 }

Crypto/src/ROT13Test.java

@@ -1,5 +1,9 @@
+package src;
+import org.junit.Assert;
 import org.junit.Test;
 
+import java.io.File;
+
 import static org.junit.Assert.*;
 
 public class ROT13Test {
@@ -61,15 +65,19 @@ public void cryptTest1() {
 
         // When
         String actual = cipher.encrypt(Q1);
+        System.out.println(actual);
+
         System.out.println(Q1);
         System.out.println(A1);
+        //  System.out.println(actual);
         // Then
         assertTrue(actual.equals(A1));
 
         // When
         String actual2 = cipher.decrypt(Q2);
         System.out.println(Q2);
         System.out.println(A2);
+        System.out.println(actual2);
         // Then
         assertTrue(actual2.equals(A2));
     }
@@ -87,5 +95,28 @@ public void cryptTest2() {
         // Then
         assertTrue(actual.equals(Q1));
     }
-
-}
+    @Test
+    public void textEncryptFile(){
+        //Given
+        File file = new File("sonnet18.txt");
+        //When
+        String expected = ROT13.encrypt("Shall I compare thee to a summer’s day?\n" +
+                "Thou art more lovely and more temperate:\n" +
+                "Rough winds do shake the darling buds of May,\n" +
+                "And summer’s lease hath all too short a date;\n" +
+                "Sometime too hot the eye of heaven shines,\n" +
+                "And often is his gold complexion dimm'd;\n" +
+                "And every fair from fair sometime declines,\n" +
+                "By chance or nature’s changing course untrimm'd;\n" +
+                "But thy eternal summer shall not fade,\n" +
+                "Nor lose possession of that fair thou ow’st;\n" +
+                "Nor shall death brag thou wander’st in his shade,\n" +
+                "When in eternal lines to time thou grow’st:\n" +
+                "So long as men can breathe or eyes can see,\n" +
+                "So long lives this, and this gives life to thee.");
+
+        String actual = ROT13.textFile("sonnet18.txt");
+        //Then
+        Assert.assertEquals(expected,actual);
+    }
+}

SimpleCrypt.iml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_5">
+    <output url="file://$MODULE_DIR$/target/classes" />
+    <output-test url="file://$MODULE_DIR$/target/test-classes" />
+    <content url="file://$MODULE_DIR$">
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>