Instructions
1.0 What version of Java to use

This coursework assignment uses some features introduced in Java 7, and a method introduced in Java 8. Please use the most recent version of Java, Java 8.

1.1 Java 7 new features
1.1.1 The diamond operator

The programs you have been given for parts A and B use the diamond operator, meaning that the type of an ArrayList can be inferred by the JVM. For example, this declaration:

ArrayList<String> details = new ArrayList<String>();
can be rewritten as:
ArrayList<String> details = new ArrayList<>();

From the left side of the declaration, the JVM infers that the ArrayList is of type String.

1.1.2 The Files class
Files, introduced in Java 7, is a class with static methods that operate on files and related data structures; it includes the method readAllLines(Path, Charset). This method reads all lines from a file, recognises standard line endings, and closes the file after use. The Dictionary class in part B uses the Java 8 method Files.readAllLines(Path) that takes only a Path parameter. Bytes from the file are decoded into characters using the UTF-8 Charset.

1.2 Other features
1.2.1 Platform-specific new lines
Because Windows and Linux have different new line symbols the files you have been given use code for new lines that will work as expected on any platform. System.lineSeparator() is used, for example, in the toString() method of ProspectiveStudent. System.lineSeparator() will return the appropriate new line character for the system it is used on. See the API for more information on the System class

When using String.format(), such as in AnagramServerEngine, “%n” is used for a new line, as n gives the platform-specific line separator.

1.2.2 Listinterface
You will note that in the files you have been given for part B, ArrayLists are declared to be of type List, as are methods that return an ArrayList. List is an interface

1.2.3 The enum type
The ProspectiveStudent class uses the enum type for some of its fields. These fields (FeeType, Gender, OfferStatus, QualificationsType) could have been Strings, in which case anything could be entered. Using the enum type allows us to restrict the user to only a few very specific entries that are appropriate for the field. For example, Gender types will only accept FEMALE, MALE and OTHER.

Part A
Consider the classes that you have been given. Currently the Admissions class will not compile as it tries to use methods in the AdmissionsFileManager class that do not exist, and a 10-argument constructor for the ProspectiveStudent class that has not been written. Once you have successfully answered the questions below, the Admissions class should compile and run. You may test the methods of the AdmissionsFileManager class by running the class, since the class has a main method with test statements. This will also test that you have answered Question 1 correctly. Do not change the main method, and also do not change any of the four test methods that the main

• AdmissionsFileManager.java method runs.
• ProspectiveStudent.java

1. The ProspectiveStudent class has one constructor that sets the fields of the class to default values for testing purposes. It does not have a constructor that allows the user to set the value of its fields. Write a second constructor that will allow the user to set every field (i.e. instance variable) of the class.

2. In the AdmissionsFileManager class, the read() method is intended to return an ArrayList<ProspectiveStudent>, containing ProspectiveStudent objects made from the data in the student_admissions_file.txt file. The method reads in 10 lines at a time from the text file, then calls another method, parseProspectiveStudent(ArrayList<String>) in order to parse those 10 lines to a ProspectiveStudent object. However, the parseProspectiveStudent(ArrayList<String>) is not complete, so the read() method does not work as intended. Complete the parseProspectiveStudent(ArrayList<String>) so that the read() method works as intended.

3. You are given the heading of the write(ArrayList<ProspectiveStudent>, String) method. Complete the method. In your answer make sure that the method does what the comment written above the heading says it will do.

4. You are given the heading of the deserialize(String) method. Complete the method. In your answer make sure that the method does what the comment written above the heading says it will do.

5. You are given the heading of the serialize(ArrayList<ProspectiveStudent>, String) method. Complete the method. In your answer make sure that the method does what the comment written above the heading says it will do.

6. Write an appropriate constructor for the AdmissionsFileManager class.

PART B

Testing the ClientGUI

You should compile and run the AnagramClientGUI.java file. To do this you will first need to compile and start AnagramServer.java. You can run both programs from the shell (cmd.exe) but will need to open the shell twice; once to get the AnagramServer started; and once to run the AnagramClientGUI. Note that the AnagramClientGUI has been hard coded to connect to a local host.

When you start the AnagramClientGUI class you should see a simple GUI with a JButton, a scrollable JTextArea and a JTextField. When you click on the 'Connect' button, if you see the message 'ERROR: Connection refused: connect', and you have the AnagramServer class running, it may be that you need to tell your firewall to allow Java through it. If this is the case you will have to restart the AnagramServer and the AnagramClientGUI once you have adjusted your firewall. Whenever you disconnect from the AnagramClientGUI you will have to restart the AnagramServer from the shell as the server is single-threaded and dies once the client has disconnected. What you should see when you run the AnagramClientGUI is the following, on the JTextArea:

Welcome IP address '127.0.0.1' to the Anagram Server. Available commands:
ANAGRAM <word> PERMUTE <word>
SHOW HELP show all anagrams of the word <word> show all permutations of the word <word> show this help

The PERMUTE command calls the permutation method, which will make all possible permutations of a word. A permutation is a rearrangement of all the objects in a collection. Suppose we have the word MAT, all possible permutations are:

MAT
MTA
ATM
AMT
TAM
TMA

If you try the command ‘permute mat’ on the GUI, you will get five permutations, as the GUI will not count ‘mat’ as a permutation of itself. Now suppose our word is TAT, all possible permutations are:

TAT
TTA
ATT
ATT
TAT
TTA

In the above, the second ‘t’ is in bold. As far as theory is concerned, a 3 letter word has 6 permutations (incuding itself). If you try ‘permute tat’ you will only see att tta as output, as the system will not return duplicate permutations.

An anagram is defined to be 'a word, phrase, or name formed by rearranging the letters of another’. In the system you have been given, we are only considering words and names, not phrases, as anagrams of a word.

Try ‘permutation mitre’ followed by ‘anagram mitre’. You may have to scroll across to see all of the permutations. You should find that from the list of unique permutations, the anagram command returns only those that are words in their own right.

When testing the GUI you should note that the History class allows you to use the arrow keys to retrieve your old commands to save typing.

Please complete the following tasks:

1. Explain why the Dictionary, PermutationFactory and AnagramFactory classes all implement the Singleton design pattern. Give your answer by writing a comment at the top of each of the above three classes, identifying: (1) how the pattern is being implemented by the class; and (2) why the pattern is being implemented in that particular class.

2. Anagrams and permutations are listed as one continuous line on the GUI, such that the user may have to scroll across to see them all. Can you alter the system so that they are listed one to a line? For example, instead of att tta output as the permutations of ‘tat’, the output would be: att & tta

After you have implemented your change, the user may now have to scroll down to see all permutations/anagrams. Make sure to use platform independent line separators, as described in section 1.2.1 above.

3. On the machine used to test the GUI, looking for anagrams of the 10 letter word ‘manchester’ took 4 minutes and 15 seconds. Longer words were not tested as they were expected to be even slower. Your system may be faster or slower but you should still find that it takes minutes to find the anagrams of a 10 character String.

It is possible to use a different Java data structure in one of the classes Dictionary, PermutationFactory or AnagramFactory such that finding anagrams is much faster. On the computer used to test the GUI, finding anagrams of ‘manchester’ (or more exactly, finding that there are not any anagrams of ‘manchester’) took 11 seconds after the improvement was made.

Make the improvement and, in a comment at the top of the class you have made it in, explain why the data structure you have chosen is an improvement in terms of speed over the original data structure. In a second comment, quantify the improvement you have made in terms of time taken to return anagrams of a particular word. You may use ‘manchester’, some other 10 letter word, or a longer word as your test data.

The data structure used to make the improvement is one already defined by Java, so you should be looking in the API for potential solutions.

Instructions 1.0 What version of Java to use This coursework as...