I'm trying to get to grips with the AndEngine, so I've recently gotten hold of their Cookbook, but there's a section that's confusing. I'm using the Eclipse IDE with the section is asking that I create two inner classes to an ObjectFactory class. I'm not sure if what it wants me to do is doable in java or specifically in Eclipse. This is the section of code the book is asking me to create.
Java Code:
package com.example.helloworld;
public class ObjectFactory {
public static LargeObject createLargeObject(final int pX, final in pY){
return new LargeObject(pX,pY);
}
public static SmallObject createLargeObject(final int pX, final in pY){
return new SmallObject(pX,pY);
}
} mh_sh_highlight_all('java');
Now this is returning errors that I should declare these two as individual classes, but I feel like I am missing something. Earlier the book asks you to create this BaseObject class.
Java Code:
package com.example.helloworld;
public class BaseObject {
@SuppressWarnings("unused")
private int mX;
@SuppressWarnings("unused")
private int mY;
[code]...
It then mentions that the two classes LargeObject and SmallObject are inner classes of BaseObject and extends this class. The ObjectFactory class is meant to determine which subtype of the base class that needs, as well as define the objects properties.
//create line Point beginOfLine = new Point(point1, point2); //ask user for second pair of coordinates System.out.print("Enter the coordinates for X2 or <Random> or <Exit>:"); userInput=keyboard.nextLine();
code part to another class but nothing..this is what a second class should be doing
1 - Write a java class called Point to represent a 2-D point (With x and y)
- The constructor should take the x & y as double
- The class should have accessor / mutator methods for all coordinates
2 - Write a java class called Line to represent a line (with a starting point and an ending point)
- The constructor arguments are the start and end points
//import utilities to be used in the program import java.util.Scanner; import java.util.Random; public class Point { //declare variables private double pointX, difX; private double pointY, difY;
For class, we need to create a word game using classes and objects.
The game is played in rounds. The player is presented with a word that is missing letters. The player has to fill in the missing spaces with their letter guesses. The words presented are chosen with a random number generator which has been provided for us. At the end of the game, the player is shown their score.
In steps, I have to:
-Welcome the player. -Present the puzzle. -Allow the player to fill in the blanks. -Have the program check responses for correct/incorrect input. -End the game if they have three misses, or continue if they complete the puzzle.
Now, to start, I have a class for the number generator, a class to store the array of 25 words, and a class for the game itself.
I am new a creating GUIs and am not quite sure how to correctly make one. I have done the inheritance parts, and created two extra appliances: a washer and dryer. Now Creating the GUI ....
Here are the instructions to my project.
Introduction to GUIs (+ some inheritance)
For this assignment, you are going to create a user interface that interacts with the setters and getters of some classes that you will create.
First, create an abstract class called Appliance. This abstract class should have two attributes (dealing with household appliances) and two abstract methods called turnOn() and turnOff(). These methods should return void.
Then, create two subclasses of Appliance that represent household appliances (like a Refrigerator or Stove ((don't use those!))). These subclasses should have two attributes that are specific to the various appliance. Each subclass should implement the turnOn() and turnOff() methods. These methods should print to the command line some information about the appliance as it turns on and off.
Now, the fun part! Create a GUI interface!
Your window should have two panels: one for each appliance subclass. Each panel should have 4 textboxes (with appropriate labels) to receive/display information that correspond to the 4 attributes (2 from Appliance and 2 from the subclass) for each subclass.You also need 2 buttons on each panel: A Get button and a Set button.
When the Get button is pressed, the text boxes should be filled with the information from the instantiated object of the appropriate subclass. When the Set button is pressed, the object should then contain the information contained that the user has altered.
In your main method, you should create an object of each subclass, and prefill it with information (either using the constructor or the setters), then display your GUI. You should now be able to get and set the information for your objects from the GUI.
At least one of your attributes for each subclass should be numeric
Note that you will need to handle incorrectly formatted input (You can use exception handling to do this if you want to. Wrapper classes also will work)
If there is text in the boxes when the "Get" button is pressed, it should be overwritten by what is in the object. Remember that these two panels should both be on screen at the same time.
You don't need 2 different windows, one window: 2 panels.
In the class below I'm trying to create a class that will accept dates in various formats and create a range. The first constructor is easy because I send it the begin date and end date as Date objects. Now I want to send a month(and year) in a constructor and derive the begin and end dates from it. In my constructor that accepts the month/year I need to put the this(startDate, endDate) at the top to be allowed, but the parameters are not built yet.
package com.scg.athrowaway; import java.util.Calendar; import java.util.Date; public class DateRange { private Date startDate; private Date endDate;
public class Color { private int red; private int green; private int blue; public Color(){ red = 0; green = 0; blue = 0; }
And i have the Light class :
public class Light { private Color color1; private boolean switchedon;
public Light(int red, int green, int blue){ //dont know what to write here . how can i use the members of the Color class here ? without using extends. } }
How to create object for "class B" and call the "function_B" from other different class D where class D has no connection with class A? Here is my program.
public class A(){ void print(){} } class B{ void function_B(){} } class C{ void function_C(){} }
Here, A, B, C are in the same package. But class D is in different package.
Design a class named Person and its two subclasses named Student and Employee. Make Faculty and Staff subclasses of Employee. There is also a MyDate class as explained below. A person has a name, address, phone number, and email address. A student has a status (freshman, sophomore, junior, or senior). Define the status as an integer which can have the value 0 (for "Freshman"),
1 (for "Sophomore"), 2 (for "Junior"), and 3 (for "Senior"),
but don't allow the status to be set to any other values. An employee has an office, salary, and dateHired. The dateHired is a MyDate field, which contains the fields: year, month, and day. The MyDate class does not explicitly inherit from any class, and it should have a no-arg constructor that sets the year, month, and day to the current year, month, and day. The MyDate class should also have a three-argument constructor that gets three int arguments for the year, month and day to set the year, month and day.
A faculty member has office hours and a rank. Define the rank as a String (for values like "Professor" or "Instructor"). A staff member has a title, which is also a String. Use data types for the fields as specified, or where one is not specified, use a data type that is appropriate for the particular field. Write a test program called TestEveryone.java that creates a Person, Student, Employee, Faculty, and Staff object, and invoke their toString() method (you don't need to call the objects' toString() method explicitly).
Note: Your MyDate.java class is the object class that your dateHired field is created from in the Employee.java class.
Do not use the Person, Employee or Faculty classes defined on pages 383 and 384 of the book. Create new ones.Here is the code I have so far concerning the employee and MyDate.
public class Employee extends Person { private String office; private double salary; //private MyDate dateHired; //7 argument constructor for employee public Employee(String name, String phoneNumber, String email, String address, String office, double salary /*MyDate dateHired*/) { super(name, phoneNumber, email, address);
The assignment is to create a SmartString class that implements a SmartStringInterface class (created by professor) and implements a few methods. We are basically taking a string and then taking various substrings and inserting, deleting them and undoing changes as well. Here are the methods in the interface to use along with the parameters.
public interface SmartStringInterface { public void insert(int pos, String sstring); public void delete(int pos, int count); public void undo(); public String toString();
The Undo is supposed to be able to be called multiple times (to be tested using a driver program that we must create) but the part that's got me is that the changes are only supposed to be stored. Currently, I am storing the "new" string after each change onto a stack, so that undo can just pop off the stack and it will revert to the previous string. Professor said that was wrong, so I don't know how to do it. Here is what I have so far (some of the code we have is using default StackADT stuff from our book, so if you need that I can post as well. You can see in the undo method where I currently save the string. We can use multiple stacks if needed, but the less the better. Must use at least 1. The exception code is already coded for us in another file also. I am only having to code these methods and the driver to test.
import java.util.Arrays; public class ArrayStack<T> implements StackADT<T> private final static int DEFAULT_CAPACITY = 100 private int top; private T[] stack;
I'm currently taking a computer program design class which has done a lot for my understanding of how to organize classes, but isn't giving me challenging enough assignments and I don't believe it's going to be covering interfaces and abstract classes, which is a shame. So I've been digging into these topics myself and decided to work on my own program (an Uno game program) that would utilize everything we've been learning and give me some practice with GUIs.
My current plan:
Have an abstract UnoCard class that determines the basic properties/methods common to all cards. Create a class for each card type extending from UnoCard, which would be - the generic card (number and color), action cards (skip, reverse, draw two), and special cards (wild, wild draw four, and blank).
Two enums, one for color, one for rank (which includes the numbers, as well as the action and special card ranks (reverse, wild, exc.) ).
A deck class would have an ArrayList <UnoCard> property and it's constructor would initialize a fresh deck.
A hand class that also has an ArrayList <UnoCards> where it gets said cards from the deck class.
A discard pile class, which contains the cards discarded and the current card in play.
A "board" class (haven't figured out a better name for it yet) which would determine/keep track of the number of players/hands, the turn order, the locations of the cards, and the winning condition.
Area of confusion and concern I'm having:
From what I've read, I want to avoid circular dependency. So if that's the case, when a card type effects the state of a "hand" or the turn order or really anything else, then in what class do I place the method(s) that effect that? If I place it in the specific card class, wouldn't that create a circular dependency? So would it be better then to have the hand class figure out what can be done with a specific card and what that specific card effects (which wouldn't that hinder the cohesion of the class?)?
I was also thinking a possible solution might be to have the non-generic card types contain methods that return values as apposed to manipulating higher level classes, such as a boolean drawCards which returns true if cards need to be drawn, false otherwise (same for skip, reverse, exc.).Then maybe the board class can determine what to do if those values are true or false (which actually seems more convoluted since only one value would be allowed to be true at any given time).
The other solution I was considering is to have a single UnoCardRules class, which serves the sole function of providing methods to determine the effects of each card, that way each card class can only worry about defining the card's state.
I am currently building a Plugin system for an application and I wanted to add a little security feature.
I have read many tutorials on this and they basically all came down to the same answer:
"Its complicated: You need a custom class loader and security manager and ... and even then its still tricky"
So I thought, before I load the classes dynamically I will simply read the class files. Why bother with a SecurityManager or ClassLoader if I can simply whitelist all allowed classes and search for all illegal Class access before I even load anything.
I'm new to Java and I have an assignment to create a Sphere class that will allow you to create Sphere objects using the code below. Then create a program called SphereTester that prompts the user for the radii of two spheres in meters. The program should display which sphere is larger and by how many cubic meters and display only four digits after the decimal point. I have the sphere class given to us for the assignment which is this:
Java Code: public class Sphere { // instance variable (i.e., a field) private double radius; // constructor for the Sphere class public Sphere(double r) { radius = r;
Why we create a driver class?Instead of creating a driver class, if we want to compile our code so will it show output? Let say, we've created a class GradeBook of the institution for students.So they can easily view their profile information and scores in different semesters.so when we have created a class for this purpose, should we create a driver class or not?What is the big advantage of creating a driver class?
I want to create a class that converts currency. I stored 2 conversion rate as constant (final) variables. In the main method, I ask the user to enter the amount in US dollars that they want to convert. Then I ask the user to enter the currencyType ("Bitcoin" or "Chuck E Cheese").
However I am stuck in the while loop:
I want to use a while loop that basically does this: If the user entered anything else ( not Bitcoin or Chuck E Chesse), then tell the user to try again, and keep reading Strings until they enter a correct currency type. If the user 3 consecutive incorrect currency types, then exit the program.
Take a look at what I have so far.. when I run the program it does not quite do what I want it to do Also, there's something wrong with one of my if statements and I want to figure out how to fix it.
Java Code:
import java.util.Scanner; public class CurrencyConverter { public static void main(String[] args) { System.out.println("----------------------------------"); System.out.println(" Currency Converter"); System.out.println("----------------------------------");
I'm new to java and trying to learn the ropes on Netbeans!What I want to do is make a class which does the following
-Asks for and reads a first number on the command line. -Asks for and reads a second number using a JOptionPane -Asks for and reads your name using a JOptionPane
I want it to output the name and the remainder of the first number divided by the second number.
I know that System is a final class and it cannot be instantiated, out is a static final variable of type PrintStream in System class and println is a method in PrintStream class.Still I don't understand why we use System.out to call println() method.To my knowledge a method can be called using an object reference, in case of static behaviors we use classname. Then why here we are using System.out.println? Can't we just create an object of PrintStream class and call the println() method as PrintStream class can be instantiated.Are there any ways of calling a method apart from those I know(I have mentioned above what I know)?
I'm learning about abstract classes and I have to create an abstract auto class with make and price of a car, then two classes with a different type of car, and finally a main to use them. Everything seems to work and when I run it it's fine but I do get an error on the main that I'm not using the local variable buick1 and acura1.I'm curious because, while it runs for me, I want to make sure I'm doing it right and don't know of another way to do the output than this. I've put all four classes but the issue is on the last one (5 and 7).
public abstract class Auto { protected String makeCar; protected double priceCar; public Auto(String newMake) { makeCar = newMake;
I have an assignment to create a Sphere class that will allow you to create Sphere objects using the code below. Then create a program called SphereTester that prompts the user for the radii of two spheres in meters. The program should display which sphere is larger and by how many cubic meters and display only four digits after the decimal point. I have the sphere class given to us for the assignment which is this:
public class Sphere { // instance variable (i.e., a field) private double radius; // constructor for the Sphere class public Sphere(double r) { radius = r;
[code]....
Here is a sample run of what the final result should look like
Enter the radius of a sphere (in meters): 1 Enter the radius of a 2nd sphere (in meters): 2 Sphere 2 is greater than Sphere 1 by 29.3215 cubic meters
I know that we can create an inner class inside an interface but i want to know that why we'll create an inner class inside an interface. I mean what is the use of creating inner class inside an interface and what is the advantage of it.
