Project #4 Solution

1. Specification




The fourth programming project involves designing, writing and testing a program that behaves like the Java command line compiler. Whenever we request that the Java compiler recompile a particular class, it not only recompiles that class but every other class that depends upon it, directly or indirectly, and in a particular order. To make the determination about which classes need recompilation, the Java compiler maintains a directed graph of class dependencies. Any relationship in a UML class diagram of a Java program such as inheritance relationships, composition relationships and aggregations relationships indicate a class dependency.




The main class P4GUI should create the Swing based GUI shown below:










The GUI must be generated by code that you write. You may not use a drag-and-drop GUI generator. Pressing the Build Directed Graph button should cause the specified input file that contains the class dependency information to be read in and the directed graph represented by those dependencies to be built. The input file should be generated by the students using a simple text editor such as Notepad. The input file associated with the above example is shown below:




ClassA ClassC ClassE

ClassB ClassD ClassG

ClassE ClassB ClassF ClassH

ClassI ClassC




Each line of this file specifies classes that have other classes that depend upon them. The first line, for example, indicates that ClassA has two classes that depend upon it, ClassC and ClassE. In the context of recompilation, it means when ClassA is recompiled, ClassC and ClassE must be recompiled as well. Using graph terminology, the first name on each line is the name of a vertex and the remaining are its associated adjacency list. Classes that have no dependent classes need not appear at the beginning of a separate line. Notice, for example, that ClassC is not the first name on any line of the file.




After pressing the Build Directed Graph button, one of following two messages should be generated depending upon whether the specified file name could be opened:

Once the graph has been built, the name of a class to be recompiled can be specified and the




Topological Order button can be pressed. Provided a valid class name has been supplied, a topological order algorithm should be executed that will generate (in the text area at the bottom of the GUI window) the list of classes in the order they are to be recompiled. The correct recompilation order is any topological order of the subgraph that emanates from the specified vertex.




An invalid class name should generate an exception and an appropriate error message will be displayed in a JOptionPane. If the graph contains a cycle among the Java classes, an exception will be thrown and a message will be displayed in a JOptionPane indicating that a cycle has been detected.




Note. In the real compiling processes, when circular dependencies exist in Java programs, the compiler must make two passes over all the classes in the cycle. For this program, it will be sufficient to display a message indicating that a cycle has been detected.




In addition to the main class that defines the GUI, a second class is needed to define the directed graph. It should be a generic class allowing for a generic type of its vertices. In this application the type of the vertices will be String.




For better processing purposes, integer values will be used to represent the vertices instead of Strings. The graph should be represented as an array list of vertices (as integer values) that contain a linked list of their associated adjacency lists. The adjacency lists should be lists of integers that represent the index rather than vertex name itself. A hash map should be used to associate vertex names with their index in the list of vertices. For the input file shown above the array list of linked lists of integers would be the following:




0 [1, 2]

[]
[3, 6, 7]
[4, 5]
[]
[]
[]
[]
[1]



Storing the vertex indices rather than the names simplifies the topological order algorithm. The hash map would associate index 0 with ClassA, index 1 with ClassC, index 2 with ClassE and so on.




The directed graph class should define methods for initializing the graph each time a new file is read in, for adding a vertex and an edge to the graph and for generating a topological order given a starting index. Other classes / methods could be also defined to achieve the program requirements and for better structuring the code.




Finally, custom checked exception classes should be defined for the cases where a cycle occurs and when an invalid class name is specified.




Your program should compile without errors.




The Google recommended Java style guide (https://google.github.io/styleguide/javaguide.html) should be used to format and document your code. Specifically, the following style guide attributes should be addressed: header comments include filename, author, date and brief purpose of the program; In-line comments used to describe major functionality of the code; the meaning and the role of variables and constants are indicated as code comments; meaningful variable names and prompts applied; class names are written in UpperCamelCase; variable names are written in lowerCamelCase; constant names are in written in All Capitals; braces use K&R style.




In addition the following design constraints should be followed: declare all instance variables private; avoid the duplication of code.




2. Submission requirements




Submit the following to the Project 2 assignment area no later than the due date listed in your LEO classroom.




All .java source files (no other file types should be submitted). The source code should use Java code conventions and appropriate code layout (white space management and indents) and comments. All submitted files may be included in a .zip file.



The solution description document P3SolutionDescription (.pdf or .doc / .docx) containing the following:
Assumptions, main design decisions, error handling;



A UML class diagram that includes all classes you wrote. Do not include predefined classes. You need only include the class name for each individual class, not the variables or methods;



A table of test cases including the test cases that you have created to test the program. The table has 5 columns indicating (i) what aspect is tested, (ii) the input values, (iii) the expected output, (iv) the actual output and (v) if the test case passed or failed. Each test case will be defined in a table row.



Relevant screenshots of program execution;
Lessons learned from the project;



Grading Rubric:




Criteria
Meets
Does Not Meet


5 points
0 points








GUI is hand coded and matches required
GUI is generated by a GUI generator or


design
does not match required design


Includes generic class for a directed graph
Does not include a generic class a directed
Design


graph


Graph is represented as an array list of
Graph is not represented as an array list


vertices that contain a linked list of their
of vertices that contain a linked list of


associated adjacency lists
their associated adjacency lists


Includes checked exception classes for cycles
Does not Include checked exception


and invalid class names
classes for cycles and invalid class names


Uses good object-oriented design practice
Does not use good object-oriented design


regarding code efficiency, encapsulation and
practice regarding code efficiency,


information hiding, class and code reuse,
encapsulation and information hiding,


high cohesion of classes, avoiding code
class and code reuse, high cohesion of


duplication.
classes, avoiding code duplication.


10 points
0 points








Produces correct topological order for all
Does not produce correct topological


cases without cycles
order for all cases without cycles


Produces error message for all cases with
Does not produce error message for all
Functionality
cycles
cases with cycles


Reports error message when file does not
Does not report error message when file


open
does not open


Reports error message when invalid class
Does not report error message when


name is entered
invalid class name is entered


Generates message confirming graph has
Does not generate message confirming


been built
graph has been built


5 points
0 points








Test cases table is defined and included in
Test cases table is not defined and


the P4SolutionDescription document
included in the P4SolutionDescription




document


Test cases include a graph without cycles
Test cases do not include a graph without
Test Cases


cycles


Test cases include a graph with cycles
Test cases does not include a graph with




cycles


Test cases include an invalid file name
Test cases do not include an invalid file




name


Test cases include an invalid class name
Test cases do not include an invalid class




name


5 points
0 points








Solution description document
No solution description document is


P4SolutionDescription includes all the
included


required sections (appropriate titled).


Documentation
Source code follows Google
Source code does not follow Google


recommendation Java style
recommendation Java style


Comment blocks with class description
Comment blocks with class description


included with each class
not included with each class


Source code is commented and indented
Source code is not commented and




indented






Overall Score
Meets
Does not meet


16 or more
15 or less