CS300 Project 4- Exceptional Piggy Bank Solution

P04 Exceptional Piggy Bank
Overview
In this assignment, we are going to develop an enhanced version of the elastic piggy bank (P03). You are going to add the following features to our famous program:
• throw exceptions to report bugs or misuse of a set of methods that we have already implemented in P03,
• load coins to the elastic piggy bank from a file,
• save the contents of the bank in a file too, with respect to a specific format,
• develop unit tests to check the correctness of the implementation of the different operations supported by our exceptional piggy bank.
Grading Rubric
20 points Immediate Automated Tests: Upon submission of your assignment to Gradescope, you will receive feedback from automated grading tests about whether specific parts of your submission conform to this write-up specification. If these tests detect problems in your code, they will attempt to give you some feedback about the kind of defect that they noticed. Note that passing all of these tests does NOT mean your program is otherwise correct. To become more confident of this, you should run additional tests of your own.
Learning Objectives
The goals of this assignment include:
• Gain more experience with creating classes and using objects.
• Develop your understanding of the difference between checked and unchecked exceptions, and get practice both throwing and catching exceptions of each kind.
• Get more practice writing tests, specifically tests that detect whether exceptions are thrown under the prescribed circumstances or not.
Additional Assignment Requirements
• All String comparisons in this assignment are CASE INSENSITIVE.
• You MUST NOT add any additional fields either instance or static, and any public methods either static or instance to your ExceptionalBank class, other than those defined in this write-up and these javadocs.
• You CAN define private helper methods to help implement the different public methods defined in this program, if needed.
• You CAN define private static helper methods to help implement the different public static methods defined in this write-up.
• All your test methods must be public static. Also, they must take zero arguments, return a boolean, and must be defined and implemented in your ExceptionalBankTester.java.
• Your ExceptionalBankTester class must implement at least the test methods defined in these javadocs with exactly the same signatures. Feel free to add additional test methods and/or consider additional test scenarios to further convince yourself of the correctness of your implementation.
• All implemented methods MUST have their own javadoc-style method headers with complete information, with accordance to the CS300 Course Style Guide.
• Feel free to reuse the information provided in these javadocs in your own java-doc style method headers.
1 Getting Started
2 Complete the implementation of ExceptionalBank class
Start first by reading the provided code. You should be familiar now with the elastic piggy bank application. Notice that there are additional methods not provided in P03 added to this project, for instance getSpecificCoinCount() and getSummary() methods. Notice also that none of the implemented methods use hard coding of the coin names or values. Our implementation should work appropriately regardless of the set of constants defined in the enum Coin and their values.
2.1 Update the constructor, addCoin(), and removeCoin() methods
Start by updating the implementation details of the constructor of the class ExceptionalBank(int), and the instance methods addCoin() and removeCoin() according to their detailed javadocs description provided within these javadocs. These methods are expected to work as described in P03 when they terminate without errors. Read carefully the provided javadoc method headers, and pay close attention to the exceptions that should be thrown by the constructor and the public methods. Add appropriate @throws annotations to the javadoc style method header of the constructor of your ExceptionalBank class, addCoin(), and removeCoin() methods. Keep in mind to NOT catch an exception within the implementation details of a method if that exception has been declared to be thrown using @throws annotation in its javadoc method header. Let the exception propagate to the method’s caller.
To check the correctness of your ExceptionalBank class so far, implement the testAddCoin(), testExceptionalBankConstructor(), testGoodExceptionalBankConstructor(), and testRemoveCoinEmptyBank() test methods with accordance to the details provided in their javadoc method headers. We provide you in the following with an example of implementation of the testExceptionalBankConstructor() test method. Feel free to reuse the provided code in
your own submission. You can define additional test scenarios to convince yourself that your test methods are able to detect defects of any wrong implementation, and pass otherwise.

/**
* This method checks whether the ExceptionalBank constructor throws an
* IllegalArgumentException with appropriate error message, when it is passed * a zero or a negative capacity. This test must fail if another kind of exception * is thrown for such test scenario.
*
* @return true when this test verifies a correct functionality, and false otherwise
*/ public static boolean testExceptionalBankConstructor() { try {
// create an exceptional bank with a negative capacity
ExceptionalBank bank = new ExceptionalBank(-10); System.out.println(
"Problem detected. The constructor call of the ExceptionalBank class did not "
+ "throw an IllegalArgumentException when it is passed a negative capacity."); return false; // return false if no exception has been thrown
} catch (IllegalArgumentException e1) {
// check that the caught IllegalArgumentException includes
// an appropriate error message if (e1.getMessage() == null // your test method should not throw
// a NullPointerException,but must return false if e1.getMessage is null
|| !e1.getMessage().toLowerCase().contains("must be a non-zero positive integer")) {
System.out.println(
"Problem detected. The IllegalArgumentException thrown by the constructor "
+ "call of the ExceptionalBank class when it is passed a negative capacity "
+ "does not contain an appropriate error message."); return false;
}
} catch (Exception e2) {
// an exception other than IllegalArgumentException has been thrown System.out.println(
"Problem detected. An unexpected exception has been thrown when calling the "
+ "constructor of the ExceptionBank class with a negative argument. " + "An IllegalArgumentException was expected to be thrown. "
+ "But, it was NOT the case."); e2.printStackTrace(); // to help locate the error within the bad ExceptionalBank // constructor code.
return false;
} return true; // test passed
}

2.2 Implement and test addCoins(String) method
The addCoins(String) is one of the new methods that we are going to add to this expanded version of the elastic piggy bank project. This method takes a String as input parameter which represents a command line to add new coins to the exceptional bank. You have to implement now this method with accordance to the details provided in its javadoc style method header comments available in these javadocs. If correctly formatted, the string provided to addCoins() method should consist of two parts separated by a colon “:”. The first part must refer to one of the constants defined in the enum Coin, which represent a coin’s name, based on a case insensitive comparison. The second part must be a positive integer. It represents the number of coins with that name that must be added to the exceptional bank as result of running addCoins() method. No coin will be added to the bank if the format of the provided string is incorrect.
Do not forget to implement the test methods related to check the correctness of the addCoins() defined in the ExceptionalBankTester class according to these javadocsfirst. The following are examples of valid string addCoins commands to add 2 quarters for instance:
• “QUARTER:2”
• “quarter:2”
• “ Quarter : 2 ”
• “quARTEr: 2”
Whereas, the following are examples of invalid (mal-formatted) string objects to add 2 quarters for instance:
• “QUARTERS:2”
• “quarter:two”
• “quarter:-2”
• “ Quart : 2 ”
• “quarter 2”
• “25 : 2”
• “quarter:2 :penny:3”
Notice also carefully that DataFormatException extends directly the Exception class. It is not a RuntimeException. It must be a checked exception.
2.3 Implement and test loadCoins() and saveBankSummary() methods
Now, implement the loadCoins() and saveBankSummary() methods in your ExceptionalBank class and their test methods in your ExceptionalBankTester class with accordance to the details provided in these javadocs. These are examples of text files whose File objects can be passed as input parameters to your loadCoins() method for instance sample1.txt, sample2.txt, and sample3.txt. The sample3.txt file contains lines mal-formatted and a line including an incorrect coin name. Those lines must be skipped. Only lines with correct format and coin names defined in the enum Coin will result in adding coins to our exceptional bank. The correct format of lines is the same as the correct format of the string provided as input to addCoins()method described in the previous section.
3 Assignment Submission
Congratulations on finishing this CS300 assignment! After verifying that your work is correct, and written clearly in a style that is consistent with the CS300 Course Style Guide, you should submit your final work through gradescope.com. The only 2 files that you must submit include:
Appendices
A Appendix A
java.util.Scanner java.io.File
Random IllegalArgumentException
IllegalStateException NoSuchElementException
NumberFormatException DataFormatException
FileNotFoundException IOException
PrintWriter PrintStream
B Appendix B
• String.split()
• String.equals()
• String.equalsIgnoreCase()
• Integer.valueOf()