i have been given a homework assignment where I have to get rid of a stack object I wrote for a program and replace it with the Stack<E> library java offers ie:
public class Stack<E> extends Vector<E> {
public Stack(); // constructor
public Boolean empty();
public E peek();
public E pop();
public E push(E item);
}
my question is do i have to actually write all these methods? Or can i just construct a stack and use the methods?
I am working on a calculator for Android.To make sure the application I am developing works with multiple operations (in the correct order) I decided to use ANTLR as part of my Java coding of the calculator. So in a separate file (.g4 file), I must declare the format of the expression.
After which I need to include the ANTLR class library in my Java Class. Then I believe I need to call a set of functions such as createLexerInterpreter and createParserInterpreter, but I am not sure. I will be having an algorithm string that will need to be parsed, such as " 3+4*5+8*9+(5/6) ".
I have two different classes called Login (in the package View) and RegButtonListener (in the package Controller). I want to use the MVC pattern.
Login creates a GUI for login. I used NetBeans GUI Builder to create it.
In the class RegButtonListener there is the code for the click of the buttons, then various listeners of the GUI.
Now I want to close the login frame at the click of a button so I want to use the dispose() method.
If I had all the code (GUI code and code of the listener) in the same file, close the frame would be easy enough to do because this.dispose(). But in my case I have two different classes.
I also have a second problem.
In Login class (in the packege View) I have included the line :
However, Netbeans tells me an error "package regButton does not exist. <identifier> expected". Why does he consider regButton a package? How can I fix these two problems?
How do I do then?
Below is the code of the two classes.
Login class. public class Login extends javax.swing.JFrame { /** Creates new form Login */ public Login() { initComponents();
I've tried implementing the compareTo method in several ways and no luck.. I keep getting errors and now it just says bad operand type for binary operator with the ">" symbol and also the less than. I'm attempting to give an implementation for the compareTo method so it compares the value of the requestDate instance variable of the two objects. if the calling object of request is greater then I have to return ""1" if it's smaller then returns "-1" and if they are the same then returns value of "0"
package librarysystem_phase2; import java.io.Serializable; /** * This class represents a request a member makes to checkout or download an item from the library. */ public class Request implements Serializable, Comparable<Request>
i was leaning inheritance and tried to implement it in Java.This is my base class vehicl.java
public class vehicle{ private int topSpeed; private int cubicCap; private String modelName; private boolean hasAlloy;
[code]...
I also have a derived class called car.java.What i wanted to do in the derived class was that i wanted to override the constructor as well as the getInfo() method from the base class.I wanted to add an additional attribute to the car "numberSeats" and display tat too when the object to car class calls the getInfo() method .It showed an error "identifier required" when i tried to compile car.java program.
import java.util.Scanner; public class car extends vehicle{ //int numberSeats; //System.out.println("Enter the number of Seats"); Scanner numberSeats=new Scanner(System.in); numberSeats=numberSeats.nextInt(); //System.out.println(numberSeats.nextInt());
[code]....
explain the errors that i get when i tried to compile car.java without using super keyword or without defining the constructor from the Car class ?
I have a gameengine stil partially in the works for pc made in java, I am attempting a port over to java but certain classes and other fuctions are not available for android that there is in java. this means that my render engine, gameengine and a couple of other clases therefore don't work.
My question is, is there anyway of using the gameengine classes that work into the project so that all i have to do is declare within the engine what i want to export for wheather this is android or java. or importing packages from the game engine project and directly linking with the ability of re-writing the odd few classes that do not work.
I am facing with a JAVA code needed for my assignment.We are implementing a Card Game.. There is a Card Class which i have not included in the code below .We have a Dec class that has various arrays..
privateCard[] masterPack >> Is a master Pack that is initialized once and has all the 52 cards.
private Card[] cards >> Is the array that has the card values from masterPack array.
My problem is :
After I called the Deck object D1, it goes to the Deck COnstrucutor OK.It then populates the values of masterPack as per the allowmasterPack method.Then it stores the values of masterPack into cards array in the init method..I get an exception when line below is executed..
cards[pack * 52 + k]= masterPack[k];
I get a java.lang.NullPointerException error..
public class debug { public static void main(String[] args) { int pack = 1; Dec D1; D1 = new Dec(pack);
You're given a number between 0 and 1 that corresponds to the probability of an event occurring.
0.7 is 70%, 0.235 is 23.5%, 0 is 0%, etc.
Someone tries to perform the event, but the event only has the given probability of occurring. Run the probability, and then if it's true, run the event. Otherwise don't run the event.
All I know how to do is generate random numbers (kind of), but if you have 0.2245 I really don't see how generating random numbers can efficiently perform that probability.....
In my Java 2D game, two tanks are controlled as follows:
Tank 1
- Move forward: UP arrow - Adjust angle of movement: LEFT and RIGHT arrows
Tank 2
- Move forward: W key - Adjust angle of movement: A and D keys
It is possible to adjust the angle of a tank while it's moving forward (e.g., striking the left arrow or the right arrow while striking the up arrow). It's also possible to move both tanks forward simultaneously.
However, while one tank is moving forward and changing its angle (e.g., striking the up and the left/right key at the same time), the other tank is only able to move forward. That is to say, it cannot adjust its angle (e.g., striking W and A at the same time won't work, while the other tank is doing the same thing; the A key is ignored).
Why is that? Here's the relevant code:
In the Board class, that has most of the game logic:
I am messing around with a Swing application and am a bit stuck as to how to join the front and back ends.This is the code for the DataManager class which is responsible for loading and saving objects and interfacing with rest of the system. The data I need displayed comes from a .txt file in the applications directory. I need to show certain aspects of the data in the JComboBoxes in the GUI class.
Java Code:
package programdataapplication; import java.io.*; import java.util.*; public class DataManager {
I have a custom library I made to make things easier for myself. I used it in a small program in NetBeans and it works fine. When I try to clean and build, it says it can't find the methods from my Library class. How do I get the library packaged into the jar?
I search this source code in google about library system then i run this in my JCreator then that error appear . I think that problem is all about "main". where can i put that main ?
I am reading the excellent book Algorithms. The author of this book is using his own libraries.
I have downloaded the libraries (it is a file called stdlib.jar) and I've store it in a directory called ~/Downloads(I am using a macbook pro).
Then I have created a project with IntelliJ Idea 14.1 using the default package (as it is the only way for a program to 'see' these libraries).
The program is running inside the ide, but because of the nature of this book, all the included code must be run from the command line.
The problem is that I cannot run for example the Average class from the command line because the system asks for the external library.
Specifically the error is :
I enter : java -cp . Average
and the Error I get is :
Exception in thread "main" java.lang.NoClassDefFoundError: StdIn at Average.main(Average.java:11) Caused by: java.lang.ClassNotFoundException: StdIn at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
[Code] ....
The Average class is the following :
public class Average { public static void main(String[] args) { //Average the numbers on StdIn double sum = 0.0; int cnt = 0;
I am working on some enhancement on application. I have a requirement. The flow is as below
In a jsp file one selection dropdown exists and a body. Selection dropdown is written as custom tag library and is included in jsp file eg tag.tld whose code exists in tag.java code for other parts of jsp are written in that *.jsp file itself. eg test.jsp
i.e test.jsp calls tag.tld to include selection dropdown
I now want a hashmap created in tag.java to be available in jsp file and I want to use it in one of the javascript function available in same jsp file for validation
i need a java library function that searches the stream of tcp packets coming to my computer from a particular ip address, so i can perform regular expressions on the contents of those packets.
i want to write a class in such a way that i should get the current execution time of another class which is running. I searched in net but it shows only how to calculate the time duration of the current class which is running. But as per my way, i need the execution time of one class from another class. How to do this ?
I will give an example below of what I am talking about. in C++ I know I would need a copy constructor because I would be pointing blindly in the heap if I deleted a object in the struct.
We have a Class/struct animal and three animals in that class/struct, a dog, a cat and a cow. Each animal has a baby and then I will give the animal a name in main. But if I delete one of the dogs puppies because I sold him wouldn't I being pointing off in the heap and have a leak?
Also since Java doesn't have structs can I put a class inside a class?
Ok, so I'm making a game with a space ship that flies around the universe and discovering new planets. It works fine so far, but I'm looking to make it perform better and be better compatible with lesser-processors.So, I'm trying to put in an FPS counter and an entirely new game loop so that my game can decide for me what FPS I should use.
I have two classes. Heres the big, main one: [Java] package cyentw.game.src; import java.awt.Color; import java.awt.Font; impor - Pastebin.com *I want to change the loop and put an FPS counter in around line 456, you can scroll past the rest if you'd like*And heres the init frame one, in case you'd like to see it for some reason.
Java Code:
package cyentw.game.src; import javax.swing.JFrame; public class Start extends JFrame{ public static JFrame frame; public static int WIDTH = 500; public static int HEIGHT = 500; public Start() {
[code]....
how to make my game loop as quickly (or a bit slower) as it can, and my FPS is static.
I have been trying to learn how to use the TabbedPane GUI. I can get the tabs to show up, but the buttons I have placed in each tab do not show up. Why this is not working. I assume that, for some reason, the buttons are not linking with their respective panels, or the panels are not linking to the respective tabs.
public class Someone { String name; int age; ArrayList <Someone> listarr = new ArrayList <Someone>(); public Someone(String name1, int age1) { name = name1; age = age1;
[code]...
1. In the compare method, what happens when it returns one of the 0, -1, or 1? How does returning such values contribute to the sorting process? How does it take in information (like I know it does through the parameters, but how exactly)?
