I just want to ask about a kind inheritance.Let say I have an interface MachineCode.I also have different classes, Binary, Hex and Octal that implements MachineCode
Question: How can I prevent java to create an Object like this:
Binary bin = new Binary();
Hex hex = new Hex();
Octal octal = new Octal();
those declaration above must be compile error,
I want to create Objects of Binary, Hex, and Octal this way:
MachineCode bin = new Binary();
MachineCode hex = new Hex();
MachineCode octal = new Octal();
i would like to create a menu like below where if i clicked on "DRAW", a frame to draw will appear and when i clicked on animate, I can animate an object drawn. I tried on using JButton, but I donno how to customize the design n so I would like to know is there other ways so tat my menu will appear as below?
I'm really new to object oriented coding. A good way to create a Text Based Game that used objects as rooms, and items. However, I can't figure out what the best way to define and use rooms and items would be. I've been at it for the past few days, and just can't think of something that works well and is easy to use.
I want to have each room have it's own "inventory" of items that the player can pickup, as well as drop items into. I want items that are dropped to maintain their properties (durability, level, ect). I would also need several methods for things like getting an item from a room by the item's display name or id. For instance, if there is a room with a Broken Iron Sword, and a Stone Dagger, I'd need to be able to get the Broken Iron Sword object with the string "Broken Iron Sword".
package home; import java.awt.Color; import java.awt.Graphics; import javax.swing.JFrame; import javax.swing.JPanel; public class Box{ int x=70; int y=70;
[Code] ....
L a = new L(); causing the error. It will be great to know why it is showing error.
import java.util.ArrayList; public class LectureRoom{ private String courseName; private String roomNumber; private String Lecturer; private ArrayList <Student> studentList;
[Code] .....
Question:
Given the following BlueJ class diagram
Lecturer class (same with previous lab, no changes needed) Student class (same with previous lab, no changes needed)
LectureRoom (changes occurs here)
1. LectureRoom has roomNumber (e.g. A301), courseName (e.g. Java), lecturer (a reference to a Lecturer object), and studentList (a reference to an ArrayList that stores Student object). 2. LectureRoom has a constructor that receives courseName, roomNumber, and Lecturer. The constructor then sets/assign the courseName, roomNumber and Lecturer. This constructor also creates the studentList arraylist object.
Its written that every constructor calls its super class constructor. And we know, constructors are called to create an object. Does it mean that if I am creating an object of a class, I am actually creating objects of all its super class???
I'm trying to use LinkedBinarySearchTree but a lot of the variables are protected in BinaryTreeNode. I am creating a BinaryTreeNode object but it still isn't allowing me to use them. The variables I am trying to use are element, left, and right.
import ch11.exceptions.*; import ch10.LinkedBinaryTree; import ch10.BinaryTreeNode; /** * LinkedBinarySearchTree implements the BinarySearchTreeADT interface with links.
*/ public class LinkedBinarySearchTree<T> extends LinkedBinaryTree<T> implements BinarySearchTreeADT<T>
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity;
[Code] .....
And then here is the data from the text file that i must extract to use to create product objects.
These continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quantity after the second comma.....
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity; //Constructor public Product( String pName, double price, int quanity )
[code]....
and then here is the data from the text file that i must extract to use to create product objects.
Dill Seed,938,34
Mustard Seed,100,64
Coriander Powder,924,18
Turmeric,836,80
Cinnamon (Ground Korintje),951,10
Cinnamon (Ground) Xtra Hi Oil (2x),614,31
Cinnamon (Ground) High Oil (1X),682,19
these continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quanity after the second comma.....
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);
In the process of creating a new class, I need to move my main method from the class SaveDate to the class DynamicTest. Below I have listed the code of both classes.The objective is to be able to run my program from the DynamicTest Class. I need understanding the process of moving my main method to a different class and creating an Object of a class and calling its method.
public class SaveData { private static final Map<String, Object> myCachedTreeMap = new TreeMap<String, Object>(); public static final List<String> getLines(final String resourceParam, final Charset charset) throws IOException{ System.out.println("Please get: "+resourceParam); if (myCachedTreeMap.containsKey(resourceParam) ) { // Use the cached file, to prevent an additional read.
I am trying to prevent data from being overwritten and appended instead when I save it to a file. I already set the append boolean to true on the FileOutputStream, but the data is still being overwritten. My code is below:
public class Main { public static void main(String[] args) { LinkedHashMultimap<String, Integer> testMap = LinkedHashMultimap.create(); //ListMultimap<String, Integer> test = ArrayListMultimap.create(); OutputStreamWriter outputStream; testMap.put("NumberA",1); testMap.put("NumberA", 33);
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I performed a print statement to verify that the LinkedHashMultiMap is not replacing values with the same key (which it was not) and realized that the overwriting was occurring when I wrote the data to a file.
I have a SplitPane, which is inside another SplitPane in the same tree hierarchy of the Scene. When I set the CSS class of the outer SplitPane, it always overwrites all CSS Settings of the inner one. How can I prevent it, so that e.g. I can assign a red divider for the outer and a green one for the inner SplitPane.
I'm using a BorderLayout, with 26 buttons to make up the alphabet from a keyboard. All the spacing looks great, but when you drag the screen out, everything gets jumbled. I would prefer to have everything stretch out, and keep the same positioning, or everything move towards the center still keeping the keyboard style positioning of the buttons but increasing the size of the window. Will a BorderLayout work for what I want, or should I try something else?
Currently to keep the buttons spaced apart I am keeping there preferred size to 25, and using horizontal and vertical struts to get the buttons positioned like I want.
This is how it is if I keep it the width and height 400, 400.
ex1.jpg
This is what happens when its stretched or shrunk.
ex2.jpg
This is an example of one of the ways I would prefer it
import java.util.*; public class DungeonsAndDragonsRedux { public static void main(String[] args) { Scanner s = new Scanner (System.in); Scanner t = new Scanner (System.in); t.useDelimiter("\n"); // Prevent scanner from reading code after nextLine().
[code]...
I have this program that is attempting to randomly equip the player with items that are randomly chosen from a list. I don't know how to prevent it from picking the same item twice though. I also don't know how to display the items that haven't been equipped, which is another requirement of this program.
Should the piece of code below set prevent the comboBox from being used? All it does at the minute return a null pointer exception. See I am using the same window but I have an if statement so if a condition is true then it will change certain aspects of the window. I want it to be true if it equals export which is does and it's populated fine but when I try and hide it if the condition equals import it returns a null pointer?
I have a JSF page (called MainPage) with a commandButton: clicking on it, I open a modal panel with a <Rich:fileUpload> component, related to a listener in corresponding bean.
When I start to upload a file, page MainPage starts to refresh, but I would like to prevent this because it's not necessary.
I tried to "play" with <Rich:fileUpload> property values, but nothing seems to work and I don't know what to do anymore.
I am making a very simple 2D array game where the player is asked what size they would like the game board to be. After entering, it displays the board and the player 'P' starts at index [0][0]. After that, they are asked for an action, which can be "up", "down", "left", "right", or "exit". I will be including some extra later (like a treasure at the end, or random obstacles), but for now this is what the game consists of.
I was instructed to "do nothing" when/if the player attempts to go out of bounds. I am trying to simply print an error, such as "Out of bounds! Try again.", then prompt the player again for an action. I even tried to make a boolean method to catch it, but to no avail.
I don't want the exception to occur at all. I just simply want the error message to print to the player and ask for another action. I would prefer not to use try/catch, or try/catch/finally since I already tried that and it still gave the exception error.This program consists of two classes. I will show the class containing the main first, then the client-server type class second.
import java.util.Scanner; public class Driver { public static void main(String[] args) { World world = new World(); boolean keepPlaying; keepPlaying = true; boolean isOutOfBounds; isOutOfBounds = false; int height = 0; int width = 0; int x = 0; int y = 0;
I am generating java script tag and javascript code in servlet and displaying it in each jsp page. i include this in every jsp in my application. I am preparing the following javascript content and diplayin each jsp
<script type="text/javascript"> BOOM.addVar (clientId = SOME universal unique ID ) </script>
the clientid will be uniqueid it gets generated every time.
Here my question is, is there any possibility the clientId will be store in browser cache or third party cache server. if yes how to prevent clientId from cache.
I don't want to prevent the whole jsp file from cache. i just want to prevent only that particular field. so that i can use advantages cache and also prevent particular header field to be cached.
Also can we prevent particular http header attribute from cache.
We're twisting our minds how to use predicate bindings correctly in the real world, i. e. beyond the trivial examples for FilteredList using simply static code but no bindings!
The problem is that our predicate must be bound to a chain of BooleanBindings, of which the final term needs the item injected into the predicate by the FilteredList. Example see purple code:
BooleanBinding a = ... StringBinding b = ... ObjectBinding<Predicate> c = Bindings.createObjectBinding(() -> item -> a.or(b.isEqualTo(item.someProperty())).get(), a, b); // Ugly: No "Bindings" style! myFilteredList.predicateProperty().bind(c);
This code has an ugly smell! It first looks like "Bindings" style, but in fact is plain old lamba mostly! But it also is slow: The code enforces splitting of a and b into separate bindings as it enforces rebuilding the chain a.or(b.isEqualTo(...)) for each single iteration of titem in turn. That induces unnecessarily creating and garbage-collecting Bindings "on the fly", which is not how Bindings are intended -- they shall be created once and simply update their value instead of getting replaced themselves to prevent wasting CPU cycles and keep memory clean.
How to do Predicate Bindings correctly (i. e. without temporarily building Bindings for each "t") ...
I have a jsp page that generate a hashtable and display its key-value pairs back to the browser. The problem is that it takes on an average about 15 minutes to build this hashtable, and as a result, I always get a timeout error. What can I do to avoid getting the timeout error without changing the server configuration for timeout
When editing a cell, the existing code would use the right/left cursor keys to move from cell to cell as opposed to from character to character when editing a cell. I planned to override the functionality by tossing in the above code as a test to see if it stops the functionality before I override it.
After placing in the above code, the above functionality no longer occurs, but now the cursor moves within the cell as I wanted which is to move from character to character instead of cell to cell. Its great it works, but it really shouldn't. Essentially the default behavior has been restored when it should have really disabled the left/right keys.
I assume there is some underlying class someplace that is doing something to affect the behavior. Since a sample can't be provided I am wondering in what scenarios would the e.consume() restore default functionality?
how to create a tree data structure in java.I tried with a class consisting of node field and arraylist child nodes. but it does not satisfy the requirement.the requirement is that,
