ICSI213-IECE213-Project 02 Solved

Project 02 Created by Qi Wang          

Click here for the project discussion recording.  

Table of Contents 

Part I: General project information ……………………………………………………………………………………… 02 

Part II: Project grading rubric……………………………………………………………………………………………….. 03 

Part III: Examples on how to complete a project from start to finish …………………………………… 04 

Part IV: A. How to test a software design? …………………………………………………………………………….06 

              B. Project description  ……………………………………………………………………………………………… 07 

             


Part I: General Project Information 

•      All projects are individual projects unless it is notified otherwise.   

•      All projects must be submitted via Blackboard. No late projects or e-mail submissions or hard copies will be accepted. 

•      Two submission attempts will be allowed on Blackboard. Only the last attempt will be graded.  • Work will be rejected with no credit if § The project is late. 

§  The project is not submitted properly (wrong files, not in required format, etc.). For example,  o The submitted file can’t be opened. o The submitted work is empty or wrong work. 

o Other issues.  

§  The project is a copy or partial copy of others' work (such as work from another person or the Internet). 

•      Students must turn in their original work. Any cheating violation will be reported to the college. 

Students can help others by sharing ideas, but not by allowing others to copy their work.  • Documents to be submitted as a zipped file: 

o   UML class diagram(s) – created with Violet UML or StarUML  o Java source file(s) with Javadoc style inline comments 

o   Supporting files if any (For example, files containing all testing data.) 

 

Note: Only the above-mentioned files are needed. Copy them into a folder, zip the folder, and submit the zipped file. We don’t need other files from the project. 

•      Students are required to submit a design, all error-free source files with Javadoc style inline comments, and supporting files. Lack of any of the required items will result in a really low credit or no credit. 

•      Grades and feedback: TAs will grade. Feedback and grades for properly submitted work will be posted on Blackboard. Students have limited time/days from when a grade is posted to dispute the grade. Check email daily for the grade review notifications sent from the TAs. If students have any questions regarding the feedback or the grade, they should reach out to their TAs first.  

•      Proper use of the course materials including the source codes:  All course materials including source codes/diagrams, lecture notes, etc., are references for your study only. Any misuse of the materials is prohibited. For example,  o Copy the source codes/diagrams and modify them into the projects. Students are required to submit the original work for the projects. For each project, every single statement for each source file and every single class diagram must be created by the students from scratch. 

o   Post the source codes and diagrams on some Web sites.  

o   Others 

  

 

             

Part II: Project grading rubric  

 

Components 
Max points 
UML Design (See an example in part II.) 
Max. 10 points 
Javadoc Inline comments (See an example in part II.) 
Max. 10 points 
The rest of the project 
Max. 40 points 
 

All projects will be evaluated based upon the following software development activities.  Analysis:  

•      Does the software meet the exact specification / customer requirements? 

•      Does the software solve the exact problem? 

Design:  

•      Is the design efficient? Code:  

•      Are there errors? 

•      Are code conventions followed? 

•      Does the software use the minimum computer resource (computer memory and processing time)? 

•      Is the software reusable? 

•      Are comments completely written in Javadoc format? 

a.      Class comments must be included in Javadoc format before a class header. 

b.      Method comments must be included in Javadoc format before a method header. 

c.       More inline comments must be included in either single line format or block format inside each method body. 

d.      All comments must be completed in correct format such as tags, indentation etc. Debug/Testing: 

•      Are there bugs in the software? 

Documentation:  

•      Complete all documentations that are required.  

 

             

Part III: Examples on complete a project from start to finish 

To complete a project, the following steps of a software development cycle should be followed. These steps are not pure linear but overlapped.  

       Analysis-design-code-test/debug-documentation. 

1)      Read project description to understand all specifications(Analysis).  

2)      Create a design (an algorithm for method or a UML class diagram for a class) (Design) 3) Create Java programs that are translations of the design. (Code/Implementation) 

4)      Test and debug, and (test/debug) 

5)      Complete all required documentation. (Documentation) 

 

The following shows a sample design. By convention. 

•      Constructors and constants should not be included in a class diagram. 

•      For each field (instance variable), include visibility, name, and type in the design. 

•      For each method, include visibility, name, parameter type(s) and return type in the design. 

o DON’T include parameter names, only parameter types are needed. 

•      Show class relationships such as dependency, inheritance, aggregation, etc. in the design. Don’t include the driver program and its helper class since it is for testing purpose only. 

 

 

  

 

 

The corresponding source codes with inline Javadoc comments are included on next page.  

import java.util.Random; 

 

/** 

Method comments must be written in Javadoc format before the method header. The first word must be a verb in title case and in the third person. Use punctuation marks properly. 
Class comments must be written in Javadoc format before the class header. A description of the class, author information, and version information are required.  
Comments for fields are required. 
*  Representing a dog with a name.  

*  @author Qi Wang  

*  @version 1.0 

 */public  class Dog{  open { 

       /** 

 TAB  * The name of this dog 

        */ 

 TAB private String name;  

        

/** 

A description of the method, comments on parameters if any, and comments on the return type if any are required.  

A Javadoc comment for a formal parameter consists of three parts:  - parameter tag,  

-  a name of the formal parameter in the design ,  

  (The name must be consistent in the comments and the header.) 

-  and a phrase explaining what this parameter specifies. 

A Javadoc comment for return type consists of two parts:  

-  return tag,  

-  and a phrase explaining what this returned value specifies 

 
*    Constructs a newly created Dog object that represents a dog with an empty name. 

        */ 

open { 
        public Dog(){  TAB  TAB                 this(""); 

       } 

       /** 

*  Constructs a newly created Dog object with a name.         * @param name The name of this dog 

        */ 

        public Dog(String name){          this.name = name; 

       } 

        

       /** 

*  Returns the name of this dog. 

*   @return The name of this dog 

        */ 

       public String getName(){          return this.name; 

       } 

        

       /** 

*  Changes the name of this dog. 

*  @param name The name of this dog 

        */ 

       public void setName(String name){               this.name = name; 

       } 

        

       /** 

*  Returns a string representation of this dog. The returned string contains the type of  

*  this dog and the name of this dog. 

*  @return A string representation of this dog 

                    */ 

                   public String toString(){ 

                          return this.getClass().getSimpleName() + ": " + this.name; 

                   } 

   

                   /** 

*  Indicates if this dog is "equal to" some other object. If the other object is a dog,  

*  this dog is equal to the other dog if they have the same names. If the other object is * not a dog, this dog is not equal to the other object.  

*  @param obj A reference to some other object 

More inline comments can be included in single line or block comments format in a method.  
*  @return A boolean value specifying if this dog is equal to some other object 

                    */ 

   public boolean equals(Object obj){         //The specific object isn’t a dog.         if(!(obj instanceof Dog)){                 return false; 

                          } 

             //The specific object is a dog.  

                          Dog other = (Dog)obj; 

                          return this.name.equalsIgnoreCase(other.name);  

       } 

} 

Part IV:  

A. How to test a software design? 

There can be many classes in a software design.  

1.       First, create a UML class diagram containing the designs of all classes and the class relationships (For example, is-a, dependency or aggregation). 

2.       Next, test each class separately. 

Convert each class in the diagram into a Java program. When implementing each class, a driver is needed to test each method included in the class design. In the driver program, 

i. Use the constructors to create instances of the class(If a class is abstract, the members of the class will be tested in its subclasses.). For example, the following creates Dog objects.  Create a default Dog object.

        Dog firstDog = new Dog(); 

                                           Create a Dog object with a specific name. 

              Die secondDog = new Dog(“Sky”); 

 ii. Use object references to invoke the instance methods. If an instance method is a value-returning method, call this method where the returned value can be used. For example, method getName can be called to return a copy of firstDog’s name.  

      String firstDogName; 

     …    firstDogName = firstDog.getName();  

You may print the value stored in firstDogName to verify.  

 

iii.      If a method is a void method, invoke the method that simply performs a task. Use other method to verify the method had performed the task properly. For example, setName is a void method and changes the name of this dog. After this statement, the secondDog’s name is changed to “Blue”.  secondDog.setName(“Blue”); 

 

getName can be used to verify that setName had performed the task.

 

iv.       Repeat until all methods are tested.  

 

                    •     And then, test the entire design by creating a driver program and a helper class of the driver program.  

i. Create a helper class. In the helper class, minimum three static methods should be included.  public class Helper{  

 //method 1  public static void start(){                           This void method is decomposed.  

                                                                            It creates an empty list.  

                            It calls the create method to add a list of objects to the list.                    And then, it calls the display method to display the list of objects.  

 } 

 

 //method 2  public static returnTypeOrVoid create(parameters if any) { 

                                                            This method creates a list of objects using data stored in text files.  

 } 

 

//method 3 

 public static returnTypeOrVoid display(parameters if any) {   This method displays a list of objects. 

 } 

}  

ii.      Create a driver program. In main of the driver program, call method start to start the entire testing process.  

 

public class Driver{ 

                              public static void main(String[] args){  

                                    Helper.start(); 

                              } 

} 

 

Notice that the driver and its helper class are for testing purpose only. They should not be included in the design diagram.  

 

B. Project description  

Project 2 ADT LinkedString                                                

Java String class is composed of a collection of characters and a set of operations on the characters. In this project, you will create a reference-based implementation on some String operations such as  chartAt, concat, isEmpty, length, substring. A doubly linked list must be used as the data structure. The class is called LinkedString.  This class must be implemented so that objects of LinkedString are immutable as String objects.  

  

In Java, a string is an immutable object (its internal states cannot be changed once it's created).  Immutable means that once the constructor has completed execution that instance made can't be altered. This is useful as it means you can pass references to the object around, without worrying that someone else is going to change its contents. Any method that is invoked which seems to modify the value, will actually create another String.  For example, three String objects, a, b, and ab, are created in the following code segment.  

 

String a = new String(“AA”);  String b = new String(“BB”); 

String ab = a.concat(b);    

 After String a = new String(“AA”); is executed, a new String object a is created.  

  a 

 



 

         After String b = new String(“BB”); b   is executed, another new String object b is created.  

 

 

After String ab = a.concat(b);  is executed,  another new String object ab is created. String  a(this string) and String  b (a string passed into method concat) are not changed due to String immutability.  Method concat simply copies the contents of a and b, and uses them to make a new String object.  

   ab 

 


 

The LinkedString class must be implemented so that LinekdString objects are immutable. The LinkedString class must use a doubly linked list, a different data structure from the one used by the String class, to store a collection of characters. One character per node. This data structure is LinkedString ‘s internal state. An immutable LinkedString object means its linked list can’t be altered once the object is created. All characteristics and behaviors of LinkedString class must be designed with the same logic as Java String class. When a LinkedString object calls a method, this LinkedString object and LinkedString object(s) passed into this method must be unchanged during execution of this method. If the method returns a LinkedString object, a new LinkedString object must be made.  The following shows how object immutability can be enforced when implementing method concat. For example, three LinkedString objects, a, b, and ab, are created in the following code segment.  

 

LinkedString a = new LinkedString (“AA”); 

LinkedString b = new LinkedString (“BB”); 

LinkedString ab = a.concat(b);   

  

After LinkedString a = new LinkedString(“AA”); is executed,  a new LinkedString object a is created with all characters stored in a doubly linked list. Each node contains a Character element, a successor and a predecessor.  

 

                              null  null 

 

 head    a 

After LinkedString b = new LinkedString(“BB”); is executed,  another new LinkedString object b is created with all characters stored in a doubly linked list. Each node contains a Character element, a successor and a predecessor.

 

                              null  null 

 

 

                          head        b 

After LinkedString ab = a.concat(b); is executed,  another new LinkedString object ab is created with all characters stored in a doubly linked list.  Each node contains a Character element, a successor and a predecessor.

 

                                         null  null 

 

 

                          head       ab 

 

Method concat must be implemented in a way in which a new linked string is made without modifying this linked string a and the other linked string b to enforce object immutability.  In order to do this, method concat should simply copy characters and use them to make a new linked string.  

     

 

     

Modifying this linked string a or other linked string b like this would violate object immutability property.  

 

 

 

Carefully implement each method, and make sure object immutability is maintained.  

 

Specification/Analysis: 

•       A Generic Node: 

Create a generic Node<E>  that can be instantiated to create a node containing an element of any reference type, a successor and a predecessor. When using it in LinkedString, replace the type parameter with reference type Character.  

 

•       LinkedString Operations: 

Note: All operations must be implemented to enforce object immutability. This means this linked string and other linked strings involved cannot be modified once after they are created.  

ü  return the char value at the specified index. (char charAt(int)).   

ü  concatenate a specified linked string to the end of this linked string (LinkedString concat(LinkedString)).

ü  returns true if and only if the length of this linked string is 0. (boolean isEmpty()) ü return the length of this linked string (int length()).  

ü  return a new linked string that is a substring of this linked string (LinkedString substring(int, int)).

 

Design: 

       Complete a UML diagram to include all classes. An interface class is usually defined to specify what the operations do. A class implementing this interface provides implementations to specify how the operations are implemented.

Exceptions should be considered when operations are designed.

        In the design, you should include the design of LinkedString,  the design of a Node  class that is needed for a doubly linked list, etc.. The following shows part of the design for this project.  

 

 
 

Code/Implementation: 

Implementation includes selecting a data structure, implementation of constructors and the operations.

A doubly linked list with an external reference to the head must be used, as the data structure.  A doubly linked list is a reference to the head of a doubly linked list.  

Three overloading constructors should be provided to make a linked string from an empty list, a char array or a String object.

•       create an empty LinkedString instance.

A  new character linked list is allocated so that it represents the sequence of 0 characters currently contained in the character list argument. (LinkedString()).  

•       create a LinkedString instance containing a sequence of characters.

A  new character linked list is allocated so that it represents the sequence of characters currently contained in the character list argument. (LinkedString(char[])).  

•       create a LinkedString instance containing same sequence of characters as a String instance.

A  new character linked list is initialized so that it represents the same sequence of characters as the String argument (LinkedString(String)).   

 

When implementing overloading methods/constructors, you should write all the codes in one method, the one that has most parameters, and let others invoke/reuse the method.  In the case, the last two constructors all have one parameter. Because a String object can be converted into a char array, therefore, all the codes should be written in the second constructor. The first constructor and the third constructor should invoke the second constructor using this reference.  

When implementing other methods, make sure all LinkedString objects involved are immutable.  It may be helpful to create helper methods for some of the LinkedString methods. If so, those helper methods should be private methods. Javadoc comments should be included.  Class comments must be included right above the corresponding class header. Method comments must be included right above the corresponding method header. All comments must be written in Javadoc style.  

 

Debug/Testing:  

Note: It is required to store all testing data in a file. It is required to use decomposition design technique.  

   To test the LinkedString design, all operations must be tested. In general, a list of LinkedString object is created,  and then, use the list to test other operations. It is not efficient to write everything in main. Method main should be small and the only method in a driver program. A helper class should be created to assist the driver. In the Helper class, minimum three static methods should be included. Method start is decomposed to create an array list of LinkedString objects(create). And then, use them in other method(displayAndMore).  Method create should add the linked strings into the list. Method displayAndMore should use the list to test other methods. More methods can be added to test other operations. Method main should call start from the driver program to start the entire testing process.   

 

Test the entire design by creating a driver program and a helper class of the driver program.  • Create a helper class. In the helper class, minimum three static methods should be included.  public class Helper{ 

 //method 1 

 public static void start(){                             This void method is decomposed.  

                                                   It creates an empty array list that can be used to store a list of LinkedString objects.

                                It calls create with a reference to the array list. create adds a list of LinkedString objects into the array list.

It calls displayAndMore with a reference to the array list. displayAndMore uses the list to test other methods.  

 } 

 

 //method 2  public static returnTypeOrVoid create(A reference to an array list){ 

       Using data stored in text files to make LinkedString objects.        Add the LinkedString objects into the array list.               Note: In this case, you will read the testing data, use some as strings and some as character                           arrays in order to test all constructors.  

 } 

 

//method 3 

 public static returnTypeOrVoid displayAndMore(A reference to an array list){ 

         For every two adjacent Linked strings in the list, if they are not empty(isEmpty returns false),         Call length and print the returned length of each linked string.

       Call charAt and print the returned first character of each linked string.

Call substring to get the first character and print the returned string of each linked string.        Call concat to concatenate and print the length of each concatenated linked string.        

 } 

} 

 

• Create a driver program. In main of the driver program, call method start to start the entire testing process.  public class Driver{ 

                              public static void main(String[] args){  

                                    Helper.start(); 

                              } 

} 

 

The sample testing file may contain items like this:

Olivia 

Oliver  

Amelia Harry Isla 

Jack 

Emily 

George Ava 

Noah 

Lily 

Charlie Mia 

Jacob 

Sophia Alfie 

Isabella Freddie Grace 

Oscar … 

 

Documentation: 

      Complete all other documents needed.