Chapter 23, Problem 4PE

Program Plan Intro

Error checking

Program plan:

Filename: “BankAccount.java”

• Include the header files in the program
• Define the “BankService” class
  • Declare the required variables
  • Define the constructor
    • Set the values
  • Define the parameterized constructor
    • Set the value
  • Define the “deposit” method
    • Call the method
    • In “try” block,
      • Calculate the new balance
      • Set the balance
        • In finally block, call the method
  • Define the “withdraw” method
    • Call the method
    • In “try” block,
      • Check the “amount” is greater than “balance”
        • Throw “InsufficientFundsException” exception
      • Check the “amount” is less than 0
        • Throw “InsufficientFundsException” exception
        • Calculate the new balance
        • Set the balance
        • • In finally block, call the method
  • Define “getBalance ()” method
    • Return the balance

Filename: “BankService.java”

• Include the required header files
• Define the class “BankService”
  • Define the “main” method
    • Declare the required variables.
    • Define the constructor
      • Set the values
    • Define the “run ()” method
      • In try block,
        • Create the objects for “Scanner” and “PrintWriter” class in another “try” block.
        • • Call “doService()” method
        • Finally, close the connection
        • • • In catch block, throw an exception
    • Define the “doService ()” method
      • Execute all command until the QUIT command or the end of input
      • Declare the string variable
      • In “try” block,
        • Call the “executeCommand ()” method and store the result in “response” variable
        • • • In “catch” block, throw “InsufficientFundsException”, “InvalidCommandException”, and “NoSuchAccountException”.
            • Print the response
    • Define the “executeCommand ()” method
      • Check the condition
        • Throw “InvalidCommandException”
        • • • Get the account number
            • Check “command” is equal to “DEPOSIT”
              • Get the amount
              • Call “deposit ()” method in “Bank” class
            • Check “command” is equal to “WITHDRAW”
              • Get the amount
              • Call “withdraw ()” method in “Bank” class.
            • Check “command” is equal to “BALANCE”
              • Print the invalid message
              • Call the “getBalance” method and store the result
              • Return the value
            • Print the balance

Filename: “InsufficientFundsException.java”

• Define the “InsufficientFundsException” class
  • Define the constructor
    • Call the “super” method

Filename: “InvalidCommandException.java”

• Define the “InvalidCommandException” class
  • Define the constructor
    • Call the “super” method

Filename: “NoSuchAccountException.java”

• Define the “NoSuchAccountException” class
  • Define the constructor
    • Call the “super” method