I had the question of what this was. [URL] ....
In summary, the Class XCopy's Main method creates an instance of the XCopy Class. So, now knowing that this can and does occur my next questions to myself were:
When would I do this?
How can this best be used?
Is this just another option available to a Java developer that has no other special significance?So far have no answers for myself.
Why I can create an Instance of a class that contains non static variables within the static main method ?
This program runs fine
import java.util.*;
public class Test{
public int j;
public static void main(String[] args) {
Test test1=new Test();
System.out.println(test1.j);
[Code] .....
I've 3 classes.
1. Circle
2. GetInputFromUser
3. testCircle
package ABC;
public class Circle {
private double radius;
public double getRadius() {
return radius;
[Code] .....
In the testCircle class, in the line: getRadius = ui1.GetInput();
It's showing the error: The method GetInput(float) in the type GetInputFromUser is not applicable for the arguments ()
And when I do: getRadius = ui1.GetInput(rad);
It's showing the error: rad cannot be resolved
So i declared a class in main class but it seems there's error when i compile:
constructor xx in class xx cannot applied to given types
This is my java class:
public class trainer extends person{
String classType;
public trainer(String name, String gender, String address, int id, String classType) {
super(name,gender,address,id);
this.classType=classType;
[Code] ....
And this is the way i declared in main class:
trainer tr = new trainer();
And what i want to do is:
tr.toString();
public class Sphere {
public double diameter;
public double volume;
public double area;
public double fourThirds = 4/3;
public Sphere(double someDiameter){
someDiameter = diameter;
[Code] ....
I am trying to get this code so that I only enter the diameter once in the sphere object1 = new Sphere(4); but I can't get it to work right. I can get the diameter to work with the calculate volume and area methods but that's it.
Im writing a simple program to understand classes and objects. Basically what I have is a file called Program.java where I have my main method.I have another file called Person.java which I want to use to create Person objects. That person can have a name, email adress, phone number, etc.I put both these files in the same folder.in Program.java my first statement is:
Java Code: import Person.java mh_sh_highlight_all('java');
My problem is that when I compile Program.java i get an error message saying that the package Person.java does not exist.So my question is, when you create a class that you want to use for objects, how do you import that class into your class with the main method so that you can use instances of your other class?
// Add range to Vehicle.
class Vehicle {
int passengers; // number of passengers
int fuelcap; // fuel capacity in gallons
int mpg; // fuel consumption in miles per gallon
// Display the range.
void range() {
System.out.println("Range is " + fuelcap * mpg);
[Code] ....
I'm compiling it in Eclipse and this continues to show in the console display
Minivan can carry 7. Exception in thread "main" java.lang.NoSuchMethodError: Vehicle.range()V
at AddMeth.main(AddMeth.java:34)
I have a snippet here that I'm working with and I have a few questions about it.
button.addActionListener( new ActionListener(){
@Override
public void actionPerformed(ActionEvent ev){
System.out.println("Button Pressed");
}
});
My questions are:
1. How is it possible to use new on ActionListener when ActionListener is an Interface, not a Class. Isn't it illegal to instantiate an Interface?
2. What is going on with the argument to addActionListener? We have the new ActionListener, but we also have a method being defined as well?
I would like to know what is the significance of instantiating an object without an assignment.
I have created a class TestClass1 with a single constructor that prints a test message.
In TestClass2, if I write "new TestClass1()" rather than "TestClass1 x = new TestClass1()" it still works, and prints the test message.
I would like to know if I do not assign an object at the time of instantiation, it cannot be referenced or reused later, then what is the significance of this type of construct and when it can be useful, and where is the object being held.
public class TestClass1 {
TestClass1() {
System.out.println("This is a test message");
}
}
public class TestClass2 {
[Code] ....
I have two classes, MonsterGame (shown below) and Monster. Monster has a public accessor method to get it's private character variable, which represents the first character of the name of the Monster in question.
I'm just a bit confused as to why am I unable to cycle through the array of Monsters I have in the MonsterGame class and call
m.getCharacter(); (pretty much the last line of code)
public class MonsterGame{
private static final char EMPTY_SQUARE = ' ';
private char[][] gameBoard = new char[10][10];
private Monster[] monsters = new Monster[4];
private int maxXBoardSize = gameBoard.length -1;
private int maxYBoardSize = gameBoard[0].length -1;
[Code] ....
I understand that there need to be instances of objects to call methods, but is that not the case here? the Monster objects are have already been created, no? Do I need to create an index for the array? is the for loop not enough?
Need to use a ComboBox from another class (Beginning Java forum at JavaRanch)
When my file is saved it has the values off the main gui's comboBox in variable 'env' which I then write to file using. I just need to access the comboBox in my second class so I can use it in main as I'm using the wrong one atm- if that makes sense?
I have a program with 4 classes, all of them in the same package, one of them is the Main class, and in that class I declared a variable named "port" of type int. One of the 3 another ones is the class Connection class, which it requires the port variable. I want to use this variable in the Connection class. How can I do it?Both classes are shown below:
Main.java
package server;
/* Imports */
/* Another variables */
int port; /* <-- IS THIS ONE */
[code]....
THIS IS MY MAIN CLASS:
Java Code:
import java.io.FileNotFoundException;
public class PrimaClasse {
public static void main(String[] args) throws FileNotFoundException {
SecondaClasse oggettoSeconda = new SecondaClasse();
oggettoSeconda.controlloNomi();
[code]....
Now it's working and from the main class i can controll the second class BUT. i want that is the main class that ask the user name, and i want pass that value to the second class. what code i must change?why eclipse wants me insert this import java.io.FileNotFoundException; and this throws FileNotFoundException for not give me an error?
How do I call a class within the main. For example, this is what i have in my code right now. I am trying to call the class BlackJackGame.
package blackjack;
public class BlackJack {
public BlackJack() {
BlackJackGame();
}
}
I have 3 source file below
//Hello.java
public interface Hello {
public void sayHello();
}
//Espanol.java
public class Espanol implements Hello {
[Code] ....
If I declare and ArrayList as follows
"public static ArrayList<Media> mediaList = new ArrayList<Media>();"
How can i access it in another class (main class)?
package Projekt;
import Projekt.Media.rating;
public class MainTest {
static MediaHandler myreg ;
public static void main(String[] args) {
myreg.addMovie(title, playTime, year, seen, directory, path, rating.four, quality, subtitles, language, writer);
}
}
I also have the variables declared but didn't include them for readability.
I've written a program just for the sake of it (to learn) and it seem's like theres quite a lot in the main method that perhaps could be split up into seperate classes. I'm not too sure where should start with this though, or what my thought process should have been as I was writing the program.
import java.util.Scanner;
public class Loops {
public static void main(String[] args) {
int answer = 16;
Scanner scan = new Scanner(System.in);
// Question
System.out.println("What is 4 x 4 ?");
[code]...
--- Update ---
here's a version without code comments as they might make it harder to read here -
import java.util.Scanner;
public class Loops {
public static void main(String[] args) {
int answer = 16;
Scanner scan = new Scanner(System.in);
System.out.println("What is 4 x 4 ?");
int userAnswerInt = 0;
[code]...
I have permanently set the path of bin of JDK 1.6 in the environment variables of my system. I am able to compile any of my java programs successfully. But when I give command to run the program I am getting an error "could not find or load main class".
When I write the command "set classpath=.;" program runs successfully. I want to know whether I have to set this classpath everytime I run a new progaram. Is there any permanent way to set classpath ?
I creates this simple code (shown below) inside a package of a major opensource code (i.e., openSHA), but when i run it the following error appears. The error mentions a class named "KT_testGmpeForScenarioRupture" that i wrote before and did not run showing exactly the same error.
Code:
package org.opensha.sha.gcim.imr.attenRelImpl;
public class KT_Test {
private static void main(String args) {
int x=4;
System.out.println("x is " + x);
}
}
Error: Could not find or load main class org.opensha.sha.gcim.imr.attenRelImpl.KT_testGmpeF orScenarioRupture
I have few queries regarding compiling v/s execution of a java program. Suppose I have a Main Class which is referring to class Test which is present in JarA. Now, at compile time, this jar JarA must be present in classpath/buildpath. So, what actually is the action performed by the compiler by referring to this jar?
Now, at runtime also, this jar should be present to execute the Main class. Is this correct? If yes, then what is the action performed by JRE when it refers to this class at runtime? WOn't all the dependencies be resolved at compile time only?
This time I have to make a Black Jack game ( I guess this is a classic) I have created Three classes for this BlackJack( Main), Card, and Player.
What I am trying to do is put the Give one card to the player and remove it from the deck into a separate procedure because I will be doing this several times during the game.
This is the code I have so far Under the class BlackJack.
Java Code:
package black.jack;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Scanner;
[Code] .....
I am using Netbeans as my IDE and I have created a program called Saluton.java
I navigate to the folder holding the class file using the command line under Windows 7 but when I issue the command java Saluton.class I get an error it cannot load or find the main class.
What is the main advantage of nested class? Rather making one class reside inside other, can't we achieve all by making it two separate classes with its own individuality?
View Replies View RelatedI made a breakout like game that runs as a applet and now i wanted to make it run in a jframe so i wrote this
Java Code:
import java.applet.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
public class BrickBuster{
public static void main(String[] args){
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
JApplet BrickBuster = new JApplet();
frame.add(BrickBuster);
BrickBuster.init();
}
} mh_sh_highlight_all('java');
It compiles fine but whenever i try running it with the java command it says it couldnt find or load main class. also i have it save in a folder called BrickBuster so i called java BrickBusterBrickBuster.class
I tried running my program on cmd but it produces the error "could not find or load main class" ...It compiles well but it just doesn't run. Here is my code:
package writedoc;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.io.IOException;
public class WriteDoc {
public static void main(String[] args) throws IOException {
String strDocument="grades.txt";
[Code] ....
I am having an issue with this code. It says that I'm missing the main class.
import java.util.Random;
import java.util.Scanner;
public class Assignment5Hangman
{
public class GetData
{
private Scanner input;
public GetData()
[Code] .....