Task 1: The OrderManager class built during the example discussion does not define a constructor. Add aprivate constructor to the OrderManager class. What changes must be made to the OrderManager class sothat client objects can create OrderManager instances?public class OrderManager (private int orderID = 0;private OrderManager () {se)//Meant to be used internallyprivate int getNextID () {++orderID;return order ID;}//public method to be used by client objectspublic void saveOrder (String item, int qty) {int ID getNextID ();System.out.println("Order ID=" + ID + "; Item=" + item +"; Qty=" + qty + " is saved. ");1 package privat;23 public class MainApp {34567894058}public static void main(String[] args) {OrderManager om = new OrderManager ();om.saveOrder ("

Task 1: The OrderManager class built during the example discussion does not define a constructor. Add a private constructor to the OrderManager class. What changes must be made to the OrderManager class so that client objects can create OrderManager instances? public class OrderManager ( private int orderID = 0; private OrderManager () 4 //Meant to be used internally private int getNextID () { } ++orderID; return orderID; //public method to be used by client objects public void saveOrder (String item, int qty) { } int ID getNextID(); System.out.println("Order ID="+ID+"; Item=" + item + "; Qty=" + qty+" is saved. "); 1 package privat; 3 public class MainApp ( public static void main(String[] args) { OrderManager om new OrderManager ().; om.saveOrder ("

Task 1: The OrderManager class built during the example discussion does not define a constructor. Add a private constructor to the OrderManager class. What changes must be made to the OrderManager class so that client objects can create OrderManager instances? public class OrderManager ( private int orderID = 0; private OrderManager () 4 //Meant to be used internally private int getNextID () { } ++orderID; return orderID; //public method to be used by client objects public void saveOrder (String item, int qty) { } int ID getNextID(); System.out.println("Order ID="+ID+"; Item=" + item + "; Qty=" + qty+" is saved. "); 1 package privat; 3 public class MainApp ( public static void main(String[] args) { OrderManager om new OrderManager ().; om.saveOrder ("

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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Hints: • For each class, it is required to implement constructors, setters, getters, toString() method, and any other necessary method • If the user tries to do an operation that could violate the state of objects, the operation should be ignored and the application should display an error message (e.g. adding a passenger to the same trip twice, etc.) Checking equality of any 2 objects should be done via the equals() method • • Testing: After implementing the required classes, design and implement a testing class to test them as follows: There is a class that will do the main job of as follows: o It has one collection to store the whole data (all trips) o It has static methods, one for each operation happens frequently o For each adding or removing operation, a message should be displayed to the user to explain the status of the operation (i.e. if it was successful or not) • Create at least 7 trips in at least 3 different dates and add them to the collection that stores the whole data…
public class VisitorPackage{// Declare data fields: an int named travelerID, // a String named destination, and // a double named totalCost.// Your code here... // Implement the default contructor.// Set the value of destination to N/A, and choose an // appropriate value for the other data fields,// Your code here... // Implement the overloaded constructor that passes new// values to all data fields.// Your code here... // Implement method getTotalCost to return the totalCost.// Your code here... // Implement method applyDiscount.//// This method applies a discount off of the total cost// of the tour. The way the discount is applied depends// on the kind of visitor.//// Child discount: the unit discount is subtracted ONCE// from the total cost of the tour.// Senior discount: the unit discount is subtracted TWICE// from the total cost of the tour.// Parameters:// - a char to indicate the kind of visitor// ('c' for child, 's' for senior)// - a double that indicates the amount of the…
Point out errors in the following codes and correct them publicclass CheckingAccount { // Create attributes account Num, Balance privateint accountNum; // Account Number privatedouble balance; // Account balance // Constructor public void CheckingAccount(int aNum, double balance) { // Call setters to initialize attribute values setAccountNumber (aNum); setBalance; } // Setters public void setAccountNumber(int aNum) { if (accountNum >= 100) { accountNum = aNum; } else {System.out.println("This account number is invalid (Account number must be at least 3 digits)!"); this.accountNum = 100; // assign a default value } } public void setBalance(double aBalance) { // make sure the value is positive if (aBalance > 0) { aBalance = balance; } else { System.out.println("This balance value is invalid (input must be positive)!"); aBalance = 0; // assign a default value } } // Getters publicvoid getAccountNumber() { return accountNum; } public void getBalance() { return balance; }…
True or False: An anonymous inner class must implement an interface or extend another class.
Design a new Account class as follows:■■ Add a new data field name of the String type to store the name of thecustomer.■■ Add a new constructor that constructs an account with the specified name, id,and balance.■■ Add a new data field named transactions whose type is ArrayList thatstores the transaction for the accounts. Each transaction is an instance of theTransaction class, which is defined as shown in Figure ■■ Modify the withdraw and deposit methods to add a transaction to thetransactions array list. Write a test program that creates an Account with annual interest rate 1.5%,balance 1000, id 1122, and name George. Deposit $30, $40, and $50 to theaccount and withdraw $5, $4, and $2 from the account. Print an account summarythat shows the account holder name, interest rate, balance, and all transactions.
Goal 1: Update the Fractions Class ADD an implementation that takes an integer as a parameter. The functionality remains the same: Instead of multiplying/dividing the current object with another Fraction, it multiplies/divides with an integer. For example; a fraction 2/3 when multiplied by 4 becomes 8/3. Similarly, a fraction 2/3 when divided by 4 becomes 1/6. Goal 2: Update the Recipe Class Add a private member variable of type int to denote the serving size and initialize it to 1. Update the overloaded extraction operator (<<) to include the serving size. New Member functions to the Recipe Class: 1. Add four member functions get the value of each of the member variable of the Recipe class: getRecipeName(), getIngredientNames(), getIngredientQuantities(), getServingSize() They return the value of the respective member variables. 2. Add and implement a member function that scales the current recipe to a new serving size. The signature of this function is: void scaleRecipe(int…
Assignment 2: - Create the first Apex class or program -- In this apex class, we have to create 2 methods -- In the first method, we will take the argument of (account id), and the return type will be (the list of contact). -- In the second method, we will take the argument of (list of account) and the return type will be ( map)
Library Information System Design and Testing Library Item Class Design and TestingDesign a class that holds the Library Item Information, with item name, author, publisher. Write appropriate accessor and mutator methods. Also, write a tester program(Console and GUI Program) that creates three instances/objects of the Library Items class. Extending Library Item Class Library and Book Classes: Extend the Library Item class in (1) with a Book class with data attributes for a book’s title, author, publisher and an additional attributes as number of pages, and a Boolean data attribute indicating whether there is both hard copy as well as eBook version of the book. Demonstrate Book Class in a Tester Program (Console and GUI Program) with an object of Book class.
Modified Circle class and test file: Add a new attribute for color (or any other new attribute) Add get/set methods for this new instance variable, including data validation in set method (assuming background is black, i.e. circle color can't be black, reset to any non-black color if black is entered ). Add a new constructor to pass the color attribute as an argument. Add an instance method to display all properties of a Circle object. Create 2 objects using different constructors in test file, with invalid data. Use this test java file test java file: class CircleTest{ public static void main(String[] args){ int num = 10; Circle c1 = new Circle(0.001); Circle c2 = new Circle("black", -9); c1.display(); c2.display(); c1.setRadius( -1); c1.setColor("black"); c1.display(); }}
class Order { private int orderNum; private double orderAmount; private double orderDiscount; public Order(int orderNumber, double orderAmt, double orderDisc) { orderNum = orderNumber; orderAmount = orderAmt; orderDiscount = orderDisc; } public double getOrderAmount() { return orderAmount; } public double getOrderDisc() { return orderDiscount; } } public class Main { public static void main(String[] args) { int ordNum = 1234; double ordAmount = 580.00; double discountPer = .1; Order order; double finalAmount = order.getOrderAmount() - order.getOrderAmount() * order.getOrderDisc(); System.out.println("Final order amount = " + finalAmount); } }
Dynamic Apex: Write test class for this apex code(Not required the output) You are working on the project in which you have to create the apex code in which your task is to define the objects dynamically by using the method argument which is api name in string and a map of string, string as a key value pair. Class Code: public static void modifySobjectData(String str , Map mapofString) { //Retrive the type of Sobject by using the getGlobalDescribe Schema.SobjectType targetType = Schema.getGlobalDescribe().get(str); //Initalize the Object Sobject newobject = targetType.newSobject(); for(String s :mapofString.keySet(O) { newobject.put(s, mapofString.get(s)); } System.debug('newObject' + newobject); //Perform the DML if(targetType != null) insert newobject; } }
Rectangle Object Monitoring Create a Rectangle class that can compute the total area of all the created rectangle objects using static fields (variables). Remember that a Rectangle has two attributes: Length and Width. Implement the class by creating a computer program that will ask the user about three rectangle dimensions. The program should be able to display the total area of the three rectangle objects. For this exercise, you are required to apply all OOP concepts that you learned in class. Sample output: Enter Length R1: 1 Enter Width R1: 1 Enter Length R2: 2 Enter Width R2: 2 Enter Length R3: 3 Enter Width R3: 3 The total area of the rectangles is 14.00 Note: All characters in boldface are user inputs.