Added some example clones to detect.

.gitignore

@@ -23,3 +23,5 @@
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err_pid*
 
+.vscode
+/target/

pom.xml

@@ -14,8 +14,8 @@
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <maven.compiler.source>1.7</maven.compiler.source>
-    <maven.compiler.target>1.7</maven.compiler.target>
+    <maven.compiler.source>1.8</maven.compiler.source>
+    <maven.compiler.target>1.8</maven.compiler.target>
   </properties>
 
   <dependencies>
@@ -69,6 +69,25 @@
           <artifactId>maven-project-info-reports-plugin</artifactId>
           <version>3.0.0</version>
         </plugin>
+        <plugin>
+    <groupId>org.jacoco</groupId>
+    <artifactId>jacoco-maven-plugin</artifactId>
+    <version>0.7.7.201606060606</version>
+    <executions>
+        <execution>
+            <goals>
+                <goal>prepare-agent</goal>
+            </goals>
+        </execution>
+        <execution>
+            <id>report</id>
+            <phase>prepare-package</phase>
+            <goals>
+                <goal>report</goal>
+            </goals>
+        </execution>
+    </executions>
+</plugin>
       </plugins>
     </pluginManagement>
   </build>

src/main/java/de/denisthiessen/algorithms/CaesarAlgorithm.java

@@ -8,6 +8,13 @@ public class CaesarAlgorithm implements IAlgorithm {
 
     @Override
     public String executeAlgorithm(String sourceString) {
+
+        // Type 2 example clone (4)
+        testNothing("Test", 1);
+        testNothing("Hello", 5);
+        testNothing("Please. Send. Help", 69);
+        testNothing("I'm stuck in this array of characters", 420);
+
         int shift = 42;
         StringBuilder encryptedText = new StringBuilder();
         for (char c : sourceString.toCharArray()) {
@@ -20,5 +27,22 @@ public class CaesarAlgorithm implements IAlgorithm {
         }
         return encryptedText.toString();
     }
-    
+
+    // Type 1 Example Clone. (1)
+    public void printHey() {
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+    }
+
+    private void testNothing(String testStringParameter, int testIntParameter) {
+        // I didn't overpromise...
+    }
 }

src/main/java/de/denisthiessen/algorithms/HashingAlgorithm.java

@@ -14,7 +14,33 @@ public class HashingAlgorithm implements IAlgorithm {
         for(char character : inputCharacters) {
             hashCode = hashCode*31 + ((int)character);
         }
+
+        // Type 2 example clone (2)
+        int i = 5;
+        i += 5;
+        i += 3;
+        i -= 4;
+        i = 3;
+        i += 1;
+        i += 1;
+        i += 1;
+        i += 1;
+        System.out.println(i);
     
         return String.valueOf(hashCode);
     }
+
+    private void type3TestFunction() {
+        // Type 3 example clone (3)
+        int y = 12;
+        y += 6;
+        y += 3;
+        y -= 2;
+        y += 8;
+        y = 1;
+        y += 4;
+        y += 2;
+        y += 93;
+        System.out.println(y);
+    }
 }

src/main/java/de/denisthiessen/algorithms/NoEncryptionAlgorithm.java

@@ -10,4 +10,18 @@ public class NoEncryptionAlgorithm implements IAlgorithm {
     public String executeAlgorithm(String sourceString) {
         return sourceString;
     }
+
+    // Type 1 Example Clone. (1)
+    public void printHey() {
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+        System.out.println("Hey!");
+    }
 }

src/main/java/de/denisthiessen/algorithms/Rot13Algorithm.java

@@ -10,6 +10,12 @@ public class Rot13Algorithm implements IAlgorithm {
     public String executeAlgorithm(String sourceString) {
         StringBuilder sb = new StringBuilder();
 
+        // Type 2 example clone (4)
+        testNothing("Test", 1);
+        testNothing("Hello", 5);
+        testNothing("Please. Send. Help", 69);
+        testNothing("I'm stuck in this array of characters", 420);
+
         for (int i = 0; i < sourceString.length(); i++) {
             char c = sourceString.charAt(i);
             if (c >= 'a' && c <= 'm')
@@ -22,7 +28,23 @@ public class Rot13Algorithm implements IAlgorithm {
                 c -= 13;
             sb.append(c);
         }
+
+        // Type 2 example clone (2)
+        int i = 1;
+        i += 1;
+        i += 1;
+        i += 1;
+        i += 1;
+        i += 1;
+        i += 1;
+        i += 1;
+        i += 1;
+        System.out.println(i);
         
         return sb.toString();
     }
+
+    private void testNothing(String testStringParameter, int testIntParameter) {
+        // I didn't overpromise...
+    }
 }

src/main/java/de/denisthiessen/algorithms/XORAlgorithm.java

@@ -19,6 +19,24 @@ public class XORAlgorithm implements IAlgorithm {
             char encryptedChar = (char) (plainChar ^ keyChar);
             encryptedText.append(encryptedChar);
         }
+
+        // Type 3 example clone (3)
+        int i = 5;
+        i += 5;
+        i += 3;
+        i -= 4;
+        i = 3;
+        testFunction();
+        i += 1;
+        i += 1;
+        i += 1;
+        i += 1;
+        System.out.println(i);
+
         return encryptedText.toString();
     }
+
+    private void testFunction() {
+        System.out.println("Hello World");
+    }
 }