the clone method of the object class is protected, so therefore we have to override this method I understand this. What doesn't make sense to me is that the protected access modifier gives access to classes in the same package and subclasses. Isn't every single class we make a subclass of the Object Class?
View RepliesI read the following comment at stackoverflow.com. It is not clear to me why equals in the code below does not override - i looked up Object class equals() and the signature is same.
public class Foo {
private String id;
public boolean equals(Foo f) { return id.equals(f.id);}
}
This class compiles as written, but adding the @Override tag to the equals method will cause a compilation error as it does not override the equals method on Object.
I have some codes as below:
public class Hello
{
public static void main(String[] args) {
new Student().fun();
}
}
class Person
[Code] ....
Now the output is "Person". if i hide the "PRIVATE" in class PERSON, that is, method PRINT in class STUDENT override the same method in its father class, then the output is "Student". Why? I mean, how does the program know what PRINT method should be called?
I'm using "standard-kepler-SR2-win32-x86_64" and have installed "jdk-8u5-windows-x64".
But eventhough I can't override a methode like that "@override", it still says me:"annotations are only available, if source lever is 1.5 or greater".
Fine, therefore I installad "jdk-8u5-windows-x64", its the higest one on that oracle side, what else is needed?
I read this tutorial about overriding equal and hashcode method. [URL] ....
I understand how to override equal method, by overriding it, We can custom our compare. I also understand How to override hashcode, To make custom hash.
But still I can not understand why we do it? why if equal method override, we must override hashcode method too?If we don't what is the problem?
To honor the above contract we should always override hashCode() method whenever we override equals() method. If not, what will happen? If we use hashtables in our application, it will not behave as expected. As the hashCode is used in determining the equality of values stored, it will not return the right corresponding value for a key.
Is it the right reason in order to override:
Because when we customize equal method so it focus on special variables,We must change the hash code too in order to match with it, so hashcode also focus on those special variable.
Write TestCabAppointment,java class where you will instantiate new CabAppointment objects and read data from RandomAccessFile and create CabAppointment objects and save them in RandomAccessFile You may use FixedLengthStringIO,java class, ICabAppointmentRecord.java interface. Complete the ReadWriteRandomAccessFile.java
CabAppointment.java (this class extends Appointment class)
private int id;
private Address startAddress;
private Address destinationAddress;
private String terminal;
private String description;
[Code].....
I have an ArrayList, based on the class which stores cricket players, their names and runs scored.When I use the Collections.sort() method my arraylist is sorted alphabetically by forename.how to OverRide the comparing method to sort by runs, and thus the code I use to sort the list?
View Replies View RelatedI am trying to make a ChessBoard class composed of an array of JLabels inside a JPanel with a grid layout. I am also trying to override the getPreferredSize method so that the board will change size when I resize the main window (in another class in which I will instancize this class as part of a larger GUI). I got this kind of layout working before, but now I am trying to get it to work with multiple classes. However, after copying in the part of the previous code corresponding to the panel's layout, I am encountering some errors that I don't know how to solve. Specifically, when I try to override the getPreferredSize method, the compiler tells me "method does not override or implement a method from a super type, " and that it can't find the method "getPreferredSize"
Here's my code:
public class ChessBoard extends JPanel//the panel that this class extends is the boardHousing
{
//mental chess board piece array
Piece mentalBoard[][] = new Piece[8][8];
//actual GUI chessboard JLabel Array
static JLabel chessBoard[][] = new JLabel[8][8];
[Code] ....
I would just think that I was overriding the method incorrectly, but the weird thing is that I got that specific section of code to work before -- the only thing different now is that there are multiple classes, so my ChessBoard class itself is extending JPanel.
i need to design an application by java that is capable of coping itself and put it somewhere else.
and i have tried ....
import java.io.*;
import java.nio.*;
public class Test1234{
[Code]....
but it just create an empty folder named "test.class" but i need the overall class file or jar file.
I want to clone some Arraylist, but the compiler apparently are just referencing the values to it's original ArrayList. I don't know what should it be:
package projetoteste;
import java.util.ArrayList;
import java.util.List;
public class TestFood {
public static void main(String[] args) {
List food=new ArrayList();
[code]....
Notice that ArrayList dailyMeal should be untouchable, but it return the changes that I made in local for-loop iteration although I didn't added nothing to it, just to it's clone.
Output:
[[[Suco, 1 , 2], [Suco, 1 , 2]], [[Suco, 1 , 2], [Suco, 1 , 2]]]
[[[►, ►, Suco, 1 , 2], [►, ►, Suco, 1 , 2]], [[►, ►, Suco, 1 , 2], [►, ►, Suco, 1 , 2]]]
I need to get a clone of a fairly deep object tree. All objects are entities and I need to set the primary keys to null. The root object:
public class Grundentscheidung implements Cloneable {
@OneToMany(cascade = CascadeType.ALL)
@JoinColumns({
@JoinColumn(name = "gesamtentscheidung_dstNr"),
@JoinColumn(name = "gesamtentscheidung_id")
[Code] .....
When I call
Grundentscheidung grundentscheidungClone = grundentscheidung.clone();
grundentscheidungClone contains the whole object tree with all dependencies, but the Tatbestand objects have their primary keys. When I use the debugger I see that Tatbestand.clone() is never called.
Is my code faulty? I would like to avoid to write a large method which sets all primary keys on the object tree to null.
My question is, how do I get my Cube to visualize in the JPanel? I've tried a bunch of add methods but they don't compile. Is there a proper method I can use to add an object to a JPanel?
import javax.swing.*;
import java.awt.Dimension;
import javax.swing.Timer;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.*;
[Code] ....
I am currently working on a Minecraft clone (called "Build"), and I'm trying draw just ONE simple dirt block, but it will only draw a square!
Here is the main class:
package game;
import game.block.DirtBlock;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;
[Code] ....
And the Block class ( the one that all Block Types are based off of):
package game;
import static org.lwjgl.opengl.GL11.*;
import java.io.IOException;
import java.nio.FloatBuffer;
import org.lwjgl.opengl.GL11;
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.TextureLoader;
import org.newdawn.slick.util.ResourceLoader;
[Code] ....
And that is the code, I'll make updates as needed.
I'm learning about inheritance and part of my problem is to create an Order with methods, then an UpdateOrder where the total price is changed by adding four dollars to it, and then a main method displaying a few orders. I've copied all three below in order. My question is when I run the program it will display the totalprice() first for the second order followed by name, number, etc.what you override always displayed first regardless of the order you put them in? (The issue is at line 31 on the third code.)
import javax.swing.JOptionPane;
public class Order { //superclass
private String customerName;
private int customerNumber;
protected int quantityOrdered;
protected double unitPrice;
protected double totalPrice;
[code]....
I am wanting to override certain methods in some Minecraft class files, and tell those class files to use code from my class files.
And no, I don't mean extend a class. When I try to extend from the main Block.Class, it makes that file as another block file for the game, or something.
So like, I want to tell the main file that handles block registries to use the code from my class file to register my custom blocks to the list of blocks, but without modifying that main block file.
Is this even something that's possible?
Also, I know that the way a file is named affects the loading order. My class files would be named using symbols to make it load right before the class file I want to override.
We have developed a theme called default.css that is extending of the default caspian.css. What we want to do is offer users the ability to override values from default.css to change colors etc. How can that be done?
View Replies View RelatedI'd like to know how to return a new array, I wrote in a method below the main method. I want to print the array but system.out.print doesn't work for arrays apparently. What structure i should use?
View Replies View RelatedI have to write a method called censor that gets an array of strings from the user as an argument and then returns an array of strings that contains all of the original strings in the same order except those with length of 4. For example if cat, dog, moose, lazy, with was entered, then it would return the exact same thing except for the words with and lazy.
Currently, my code so far just prints [Ljava.lang.String;@38cfdf and im stuck.
import java.util.Scanner;
public class censorProgram {
public static void main (String args[]){
Scanner input = new Scanner (System.in);
System.out.println ("How many words would you like to enter?");
int lineOfText = input.nextInt();
[Code] ....
I have to make new string array in the method and return words without four letters in the main method
Consider the following recursive method that calculates the greatest common divisor using Euclidean method.
PHP Code:
public static int GCD ( int x , int y )
{
if ( y == 0 )
return x;
else if ( x >= y && y > 0)
return GCD ( y , x % y );
else return GCD ( y , x );
}
Trace the above method for x=32 and y=46
Alright, I don't understand how to link my compress method to my return statement method "getPText". Also in my compression I only want it to compress for 3 or more consecutive letters.
import java.util.Scanner;
class RunLengthCode {
String pText;
String cText;
void setPText(String PText) {
pText = "";
}
[Code]...
I have two classes (Daughter and Son) that contain some very similar method definitions:
public class Family {
public static void main(String[] args) {
Daughter d = new Daughter();
Son s = new Son();
d.speak();
s.speak();
[Code] .....
Each of those classes has a "speak" method with two out of three lines being identical. I could move those into a parent class, but I need each of the child classes to continue to exhibit its unique behavior. I'm trying the approach below, which replaces the unique code with a call to a "placeholder" method that must be implemented by each child class:
public class Family {
public static void main(String[] args) {
Daughter d = new Daughter();
Son s = new Son();
[Code] .....
This works and moves the shared code from two places (the Daughter and Son classes) into one place (the new Mother class, which is now a parent class of Daughter and Son). Something about this feels a bit odd to me, though. It's one thing for a child class to override a parent class's methods to extend or alter their behavior. But, here, I've implemented an abstract method in the parent class to alter what happens when the parent class's method (speak(), in this case) is called, without overriding that parent class method itself.
I am just trying to test this array, for a locker combination program that involves classes...but the array is printing out the whacky numbers for the location. When I try to call the method in the main, it does not work. How do I call a method that exist within a class into the main method?
public class locker {
public static void main(String[] args) {
CombinationLock();
[code]....
Which method is used while passing or returning a java object from the native method?
View Replies View RelatedI am trying to call a private method to another method that are located in the same class.
I am trying to call prepareString to the encode method below.
Java Code:
public class ShiftEncoderDecoder
private String prepareString(String plainText)
{
String preparedString = "";
for(int i = 0 ; i < plainText.length();i++)
if(Character.isAlphabetic(plainText.charAt(i)))
[Code] .....
I am currently working on a dice game. I have a private method called rollDice and it performs the action of rolling two dice. For my project, I need to create another method called playerRolls and I am supposed to invoke the rollDice method in the playerRolls method and perform actions based off of that. My question right now is how do I invoke a method into another method of the same class?
View Replies View RelatedI need to write a method that will consume string representation of Object type and will return one object of this type. How to set return type for the method in this case?
Here is exmaple :
public <?> identifyType(String typeString){
if (typesString.matches("String")){
return new String("");
}else if (typeString.matches("Integer")){
return new Integer(0);
}
//....etc..}