Part 4 Completed and Annotated.

src/AssessmentPartFour.java

 import java.util.ArrayList;
+import java.util.HashMap; //Imports hash maps.
+import java.io.*; //Imports all classes from java.io package.
+import java.util.Scanner; //Imports scanner to read text file.
 import java.util.List;
 
 public class AssessmentPartFour {
@@ -7,15 +10,60 @@ public class AssessmentPartFour {
 	
 	public int loadMorseFromFile(String filename)
 	{
+		File mFile = new File(filename); //Opens the file.
 		
-		return 0;
+		morseCode.clear(); //Empties or clears the global array morseCode.
+		
+		Scanner sc; //Defines the scanner.
+		
+		try { //Tries to open the file.
+			sc = new Scanner(mFile); //Initialises the scanner with the file.
+			String nLine;
+			while (sc.hasNextLine()) { //Repeats every time there is another line.
+				nLine = sc.nextLine();
+				morseCode.add(nLine); //Adds the next line to the morseCode array.
+			}
+			sc.close(); //Closes the file.
+		} catch (FileNotFoundException e) { //If the file cannot be found the exception is caught.
+			System.out.println(e.getLocalizedMessage()); //Prints out the localised message for the error.
+		}
+		
+		
+		return morseCode.size(); //Returns the size of the morseCode array.
 		
 		
 	}
 	
+	public char morseToEnglish(String findCode) { //Method to convert morse code to a character.
+		//Defines and initialises two arrays to store the letters and their corresponding morse code value.
+		char[] letters = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','1','2','3','4','5','6','7','8','9','0'};
+		String[] code = {".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--..",".----","..---","...---","...--","....-",".....","-....","--...","---..","----.","-----"};
+
+		//Defines and initialises a HashMap.
+		HashMap<String, Character> keys = new HashMap<String, Character>();
+ 
+		for(int i=0;i<letters.length;i++) { //For length of the letters array.
+			keys.put(code[i], letters[i]); //Add to the hash map each code and their corresponding character value. (Pairs)
+		}
+		
+		return keys.get(findCode); //Gets the character from the HashMap, using the morse code as the key.
+	}
+	
 	public String translateMorse()
 	{
-		return "";
+		String message = ""; //Initialises the final message.
+		for (int i=0; i<morseCode.size();i++) { //Iterates to length of the morse code message.
+			if(morseCode.get(i).equals("/")) { //If the code is equal to a / then the whitespace is added to the message.
+				message = message + " ";
+			}
+			else {
+				//Calls the method to return the English character and adds it to the message.
+				char toAdd = morseToEnglish(morseCode.get(i));
+				message = message + Character.toString(toAdd);
+			}
+		}
+
+		return message; //Returns the final message.
 	}