Below is the code for Lab04StringLinkedBag.java CISY 254 Lab 4-Linked Lists Due
ID: 3671718 • Letter: B
Question
Below is the code for Lab04StringLinkedBag.javaCISY 254 Lab 4-Linked Lists Due Saturday 2/27/2016 11:59 pm Monday/Thursday Purpose: To implement a linked list of Strings using the "Bag" approach Task: Write the StringNode class following the UML below and write the StringLinkedBag following the UML below. Test using the Lab04StringLinkedBag.java provided by the instructor (Lab 04 Files folder in Lab Files folder in Lion's Den) (.zip contains a NetBeans Project shell) NOTE: Tester assumes that toString() has been implemented correctly in StringLinkedBag UML UML for StringNode StringNode -data:String link: StringNode +String Node(initialData: String, initialLink StringNode) + getData0:String + getLink):StringNode + setData(initialData:String):void +setLink(initialLink String Node)void UML for StringLinkedBag StringLinkedBag head: StringNode numElements:int + StringLinkedBag) + getsize():int +toString)-String + add(element : String):void +exists(target: String): boolean + coun + remove(target: String): boolean es(target: String): int Note: This will be revisited and made generic in Lab 5, so consider this as a first-of-a-series prototype Submitting the Lab E-mail your StringNode.java and StringBag-java files to the instructor's email account at stephen.brower@raritanval.edu with a subject of CISY 254 Lab 4 see the syllabus for the Late Policy [ 3/3 last day for "life happens" J and Cheating Policies
Explanation / Answer
StringNode.java
public class StringNode
{
//region FIELDS
private String data; //holds the string
private StringNode link; //the node this one is linked to
//endregion
//region CONSTRUCTORS
/*
Default constructor. Initializes with a data item and a link.
@param initialData The initial string this node is initialized with.
@param initialLink The initial string this node is initialized with.
*/
public StringNode(String initialData, StringNode initialLink)
{
data = initialData;
link = initialLink;
}
//endregion
//region ACCESSORS
/*
Returns the data associated with this node.
@returns The data associated with this node.
*/
public String getData()
{
return data;
}
/*
Returns the link associate with this node.
@returns The link associated with this node.
*/
public StringNode getLink()
{
return link;
}
//endregion
//region MUTATORS
/*
Changes the data associated with this node.
@params The new data to be associated with this node.
*/
public void setData(String newData)
{
data = newData;
}
/*
Changes the link associated with this node.
@params The new data to be associated with this node.
*/
public void setLink(StringNode newLink)
{
link = newLink;
}
//endregion
}
StringLinkedBag.java
public class StringLinkedBag
{
//region FIELDS
private StringNode head; //the first node in the list
private int numElements; //the number of elements in the list
//endregion
//region CONSTRUCTORS
/*
No-args constructor. Initializes to 0 elements with no head node.
*/
public StringLinkedBag()
{
head = null;
numElements = 0;
}
//endregion
/*
Returns the size of the list.
@returns the size of the list.
*/
public int getSize()
{
return numElements;
}
/*
Checks whether or not the given element exists within the list.
@params The element to be searched for in the list.
@returns Whether or not the element exists.
*/
public boolean exists(String element)
{
boolean elementFound = false;
for (StringNode cursor = head; cursor != null && !elementFound; cursor = cursor.getLink())
{
if (cursor.getData().equalsIgnoreCase(element))
{
elementFound = true;
}
}
return elementFound;
}
/*
Counts the number of times an element is contained within the list.
@params The element to be searched for.
@returns The number of times the element has been found within the list.
*/
public int countOccurrences(String element)
{
int occurrences = 0;
for (StringNode cursor = head; cursor != null; cursor = cursor.getLink())
{
if (cursor.getData().equalsIgnoreCase(element))
{
occurrences++;
}
}
return occurrences;
}
//endregion
//region MUTATORS
/*
Add an element to the list.
@param element The element to be added to the list.
*/
public void add(String element)
{
head = new StringNode(element, head);
numElements++;
}
/*
Removes the element from the list.
@param element The element to be removed.
*/
public boolean remove(String element)
{
boolean elementFound = false;
StringNode targetNode = head;
for (StringNode cursor = head; cursor != null && !elementFound; cursor = cursor.getLink())
{
if (cursor.getData().equalsIgnoreCase(element)) {
elementFound = true;
targetNode = cursor;
}
}
if (elementFound)
{
targetNode.setData(head.getData());
head = head.getLink();
numElements--;
}
return elementFound;
}
//endregion
//region OVERRIDES
/*
Returns the list as a single string.
@returns The list as a single String.
*/
public String toString()
{
//first check for a null head, or 0 elements
if (head == null || numElements == 0)
{
return "empty";
}
String returnString = "";
for (StringNode cursor = head; cursor != null; cursor = cursor.getLink())
{
returnString += cursor.getData();
if (cursor.getLink() == null)
{
returnString += ".";
}
else
{
returnString += ", ";
}
}
return returnString;
}
//endregion
}
Lab4_LinkedListStringBag.java
public class Lab4_LinkedListStringBag
{
/**
* The main method is the program's starting point.
* @param args the command line arguments
*/
public static void main(String[] args)
{
// creates a linked bag
StringLinkedBag cheeseBag = new StringLinkedBag();
//test data
String[] stringsToAddArray = {"Swiss", "Colby", "MonteRey jack", "Cheddar",
"Havarti", "MoNterey JAck", "Alpine Lace",
"Wisconsin Cheddar"};
String[] stringsToFindArray = {"edam", "sWiss", "coLBy",
"monTereY jaCk"};
boolean[] expectedFindResults = {false,true,true,true};
String[] stringsToCountArray = stringsToFindArray.clone();
int[] expectedCountResults = {0,1,1,2};
String[] stringsToRemoveArray = {"Edam", "Colby", "Alpine Lace", "Swiss"};
boolean[] expectedRemoveResults = {false,true,true,true};
// show initial bag
displayBag("Display Bag on startup",cheeseBag);
// add some cheeses to bag
for (String stringToAdd : stringsToAddArray)
addValue(stringToAdd,cheeseBag);
// show bag after adds
displayBag("Display Bag after adds",cheeseBag);
// look for some cheeses
for (int i = 0; i < stringsToFindArray.length; i++)
displayValueExists(stringsToFindArray[i],cheeseBag,expectedFindResults[i]);
// show bag after searches
displayBag("Display Bag after searches",cheeseBag);
// count some cheeses
for (int i = 0; i < stringsToCountArray.length; i++)
displayCountValue(stringsToCountArray[i],cheeseBag,expectedCountResults[i]);
// show bag after counted
displayBag("Display Bag after counts",cheeseBag);
// remove some cheeses AND display
for (int i = 0; i < stringsToRemoveArray.length; i++)
removeValue(stringsToRemoveArray[i],cheeseBag,expectedRemoveResults[i]);
}
/**
the displayValueExists method displays whether aValue exists in aBag
@param aValue the String to look for
@param aBag the StringLinkedBag to look in
*/
public static void displayValueExists(String aValue, StringLinkedBag aBag,
boolean shouldSucceed)
{
if (aBag.exists(aValue))
{
System.out.print( aValue + " is in the bag");
if (!shouldSucceed)
System.out.print(" <==== issue - shouldn't exist");
else
System.out.print(" -good");
}
else
{
System.out.print( aValue + " is not in the bag");
if (shouldSucceed)
System.out.print(" <==== issue - should exist");
else
System.out.print(" -good");
}
System.out.println();
}
/**
the displayBag method displays the linked bag
@param heading a String to display before the bag
@param aBag the StringLinkedBag to display
*/
public static void displayBag(String heading, StringLinkedBag aBag)
{
System.out.println(heading);
if (aBag.getSize() == 0)
{
System.out.println("Empty: Check [ " + aBag + "]");
}
else
{
System.out.println("Not Empty: Check [ " + aBag + "]");
System.out.println("Size: " + aBag.getSize());
}
System.out.println();
}
/**
the displayCountValue method displays the number of aValue that occurs in aBag
@param aValue the String to look for
@param aBag the StringLinkedBag to look in
*/
public static void displayCountValue(String aValue, StringLinkedBag aBag,
int expectedCount)
{
int count = aBag.countOccurrences(aValue);
System.out.printf("# of %20s in bag: %2d", aValue, count );
if (count != expectedCount)
System.out.print(" <==== issue - expected "+expectedCount);
else
System.out.print(" -good");
System.out.println();
}
/**
the removeValue method attempts to remove aValue from aBag
@param aValue the String to remove
@param aBag the StringLinkedBag to look in
*/
public static void removeValue(String aValue, StringLinkedBag aBag,
boolean shouldSucceed)
{
boolean wasInBagBeforeRemoval;
if (aBag.toString().toLowerCase().indexOf(aValue.toLowerCase()) == -1)
wasInBagBeforeRemoval = false;
else
wasInBagBeforeRemoval = true;
// was remove successful?
if (aBag.remove(aValue))
{
// remove() returned true
System.out.print(aValue+" removed");
// should remove have suceeded?
if (shouldSucceed)
{
// double check it is really gone
if (aBag.toString().toLowerCase().indexOf(aValue.toLowerCase()) == -1)
System.out.print(" -correct return- value gone from bag -good");
else
System.out.print(" -correct boolean return- but value is still in bag <==== issue");
}
else // remove should not have succeeded
{
// remove returned true but false expected
// was it there?
if (wasInBagBeforeRemoval)
{
// how can something that shouldn't have been in the bag
// had actually been in the bag?
System.out.print(" -uhhhhh...possible logic issue in tester-contact instructor<<Code A");
if (aBag.toString().toLowerCase().indexOf(aValue.toLowerCase()) == -1)
System.out.print("01>> <==== issue");
else
System.out.print("02>> <==== issue");
}
else
{
// is it there
if (aBag.toString().toLowerCase().indexOf(aValue.toLowerCase()) == -1)
System.out.print(" remove() returned true and shouldn't have / it's not in bag <==== issue");
else
System.out.print(" remove() returned true and shouldn't have and it's still in bag <==== issue");
}
}
}
else // remove returned false
{
// remove() returned false
System.out.printf(aValue+" remove failed");
// should remove have returned true?
if (shouldSucceed)
{
// remove() returned false, should have returned true
// was it actually removed?
if (aBag.toString().toLowerCase().indexOf(aValue.toLowerCase()) == -1)
{
// remove() returned false but did remove it
System.out.print(" - remove worked but returned false <==== issue");
}
else
{
// remove() returned false and that was expected
// make sure it isn't there
System.out.print(" - remove returned false item still in bag <==== issue");
}
}
else // remove() returned false as exptected
{
if (aBag.toString().toLowerCase().indexOf(aValue.toLowerCase()) == -1)
{
if (wasInBagBeforeRemoval)
{
// how can something that shouldn't have been in the bag
// had actually been in the bag?
System.out.print(" -uhhhhh...possible logic issue in tester-contact instructor<<Code B02>> <==== issue");
}
else
System.out.print(" wasn't in bag before removal so it was expected to fail remove-good");
}
else
{
System.out.print(" -received expected false return value, but it is still in the bag <==== issue");
}
}
}
System.out.println();
displayBag("Display Bag after trying to remove: ["+aValue+"]",aBag);
}
/**
the addValue method adds aValue to aBag
@param aValue the String to remove
@param aBag the StringLinkedBag to look in
*/
public static void addValue(String aValue, StringLinkedBag aBag)
{
System.out.print("Currently: "+aBag.getSize()+" adding: "+aValue);
aBag.add(aValue);
System.out.println("...added...now: "+aBag.getSize());
// uncomment next line if you need to debug
//displayBag("Display Bag after adding: ["+aValue+"]",aBag);
}
}
output
Display Bag on startup
Empty: Check [ empty]
Currently: 0 adding: Swiss...added...now: 1
Currently: 1 adding: Colby...added...now: 2
Currently: 2 adding: MonteRey jack...added...now: 3
Currently: 3 adding: Cheddar...added...now: 4
Currently: 4 adding: Havarti...added...now: 5
Currently: 5 adding: MoNterey JAck...added...now: 6
Currently: 6 adding: Alpine Lace...added...now: 7
Currently: 7 adding: Wisconsin Cheddar...added...now: 8
Display Bag after adds
Not Empty: Check [ Wisconsin Cheddar, Alpine Lace, MoNterey JAck, Havarti, Cheddar, MonteRey jack, Colby, Swiss]
Size: 8
edam is not in the bag -good
sWiss is in the bag -good
coLBy is in the bag -good
monTereY jaCk is in the bag -good
Display Bag after searches
Not Empty: Check [ Wisconsin Cheddar, Alpine Lace, MoNterey JAck, Havarti, Cheddar, MonteRey jack, Colby, Swiss]
Size: 8
# of edam in bag: 0 -good
# of sWiss in bag: 1 -good
# of coLBy in bag: 1 -good
# of monTereY jaCk in bag: 2 -good
Display Bag after counts
Not Empty: Check [ Wisconsin Cheddar, Alpine Lace, MoNterey JAck, Havarti, Cheddar, MonteRey jack, Colby, Swiss]
Size: 8
Edam remove failed wasn't in bag before removal so it was expected to fail remove-good
Display Bag after trying to remove: [Edam]
Not Empty: Check [ Wisconsin Cheddar, Alpine Lace, MoNterey JAck, Havarti, Cheddar, MonteRey jack, Colby, Swiss]
Size: 8
Colby removed -correct return- value gone from bag -good
Display Bag after trying to remove: [Colby]
Not Empty: Check [ Alpine Lace, MoNterey JAck, Havarti, Cheddar, MonteRey jack, Wisconsin Cheddar, Swiss]
Size: 7
Alpine Lace removed -correct return- value gone from bag -good
Display Bag after trying to remove: [Alpine Lace]
Not Empty: Check [ MoNterey JAck, Havarti, Cheddar, MonteRey jack, Wisconsin Cheddar, Swiss]
Size: 6
Swiss removed -correct return- value gone from bag -good
Display Bag after trying to remove: [Swiss]
Not Empty: Check [ Havarti, Cheddar, MonteRey jack, Wisconsin Cheddar, MoNterey JAck]
Size: 5
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