I will like to add to the questions about constructors and its this. I have a class A with a constructor, i have a class B which initialize the constructor. also i have a class C which needs a variable in class A but doesn't need to initialize the constructor of A. the question how do i access the variable of class A without initializing the constructor.
I have 2 classes. TestClassA has 1 getter and 1 setter. From my second class, TestClassB, I want to access the getter method of TestClassA. If I try to access it, I get null. How do I do it?I do not want the methods to be declared as static. How can the getter method value be printed in TestClassB (without marking anything as static)?
public class TestA { private String name; public String getName() { return name;
I've been unable to figure out how to access an objects data from another class. I ended up missing a lesson in java and haven't been able to catch up on this topic on my own through my textbook.
Error: has private access
Code:
public class TestCoffeeDrinker { public static void main(String[] args) { Coffee latte = new Coffee("Starbucks Tall Latte", 2.85); Coffee mocha = new Coffee("Starbucks Grande Mocha", 3.95); Coffee mcdonalds = new Coffee("McDonalds McCafe", 0.99); System.out.println(mcdonalds.toString());
why I cant access a variable from another class, in particular why in the main class cant i assign " quiz1 = getQuizOne();" ? It constantly giving me error.
Java Code:
import java.util.Scanner; public class Grade { private int quiz1, quiz2, midtermExam, finalExam = 0; public static void main(String[] args) { Student John = new Student(); John.StudentData();
I make a coding a subject system for my internship project, I use JComboBox to choose name of faculty. I want to call selected item of faculty from another class to choose subject under the selected faculty.
How can I call selected item from another class?
This is my coding for select faculty.
public class lectInterface(){ private void saveDataActionPerformed(java.awt.event.ActionEvent evt) { String staff_id=staffID.getText(); int staff_Id=Integer.parseInt(staff_id); String Name=staffName.getText();
[Code] ....
and below is coding for another class
try{ LectInterface lI = new LectInterface(); String host = "jdbc:derby://localhost:1527/STUDLECDB"; String uName = "studlecdb"; String uPass = "studlecdb"; Connection con = DriverManager.getConnection( host, uName, uPass );
I have a linked list of objects of a class I created called BaseballPlayer. I also have a Fielder and Pitcher class that extends BaseballPlayer. The linked list and list nodes accept elements of type BaseballPlayer. I put into the linked list both Fielder objects and Pitcher objects. The Pitcher class has a method that returns a float variable that is only found in the Pitcher class called EarnedRunAverage. However, in my main program it won't let me access the method. It says: The method getERavg() is undefined for the type BaseballPlayer. It does however, let me access methods in the super-class BaseballPlayer.
Here is main code and the Pitcher class code.
ListNode p = list.getFirst().next; while(p!=null){ if(p.player instanceof Fielder){ sortedFielders.append(Integer.toString(p.player.getNum()) +',');
Why can't I access a method from another class? For example, I want to get the value of get method from another class. It's giving me an error on if(getExamType() == 'M') That's what I've done, for example:
Java Code:
public static Exam[] collateExams(Exam[] exams){ Exam [] r = new Exam[50]; r = exams; Exam [] finalExam = new Exam[50]; for(int i = 0; i < r.length; i++) { if(getExamType() == 'M') { } } return r; mh_sh_highlight_all('java');
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.
import java.util.Arrays; import java.util.Comparator; class SimpleHolder extends Object { private final int value; public SimpleHolder(int value) { this.value = value;
[Code] ....
According to The Java Tutorial, static nested classes should not have access to other members of the enclosing class. I'd suppose to get compile-time error in the BasicComparator class. However, my code compiles just fine. Am I missing something?
I have two classes built for this assignment. One with getters, setters and constructor and a test class. The test class works fine up until the point when the user wants to (M)odify an employee that he/she built with the loadEmployee method. What happens is I need to enter multiple "M" inputs before anything pops up, and when something pops up, it's the displayMenu instead of modifyEmployee method. I imagine it has something to do with the amount of sc.nextLine()
import java.util.Scanner; // utilize scanner via console import java.text.NumberFormat; // allows numbers to be format in form of currency //Example of "big loop" in main to repeat using a No Trip (0,N) test first public class EmployeeTest { // space provided to make code easier on eyes...
I have been asked to write a program with 3 classes(an interface, a store and a product class) and I have been going ok until I need to display data on the interface that is held in the product class. At the moment the code will compile fine but when I run the program and try to use the writeOutput() method I get a stack overflow error.
I realise now that it is because of a non-terminating recursive call, however I can not think of a solution on how to fix the problem. And just to clarify, what I am aiming to do is have the MatesTerminal class display the data for name that is stored in the Product class(I have no way of determining which product to display at this time, so I would like to be able to display the data for all three products if possible). Anyway this is what I have so far:
The method from the MatesTerminal Class:
private void writeOutput() { int productChoice; Scanner console = new Scanner(System.in);
I am having hard time to grasp the concept of java as i am beginner. according to different sources found in internet, only one class is written in one source file. and all those class can be accessed through the main class. my question is
1.can we access one class present in one source file, through another class present in another source file [not through the class containing main method]?
2.can we create more than 1 class in same source file?is there special way to do it? i do get error always when i try to do so 3.can multiple classes contain main method? or should there be only single class containing it?
I'm trying to access class file which is inside the package and package is inside the jar file but I can't access that class file inside my source file . All files are on desktop .
how to get access from variables in a super class or a subclass. Here is what I got:
1) I have a super class that is in Jar file, I created a link in Eclipse, I know that the link is created correctly, I am going to concentrate just in one variable, so I don’t have to put all the code here firstName; in the super class(the one that is define in the path)
public class CommissionEmployee { // Field descriptor #6 Ljava/lang/String; private java.lang.String firstName;
I would like to pass a variable I have in my main to my JFrame. In my main I calculate which pictures I should show in my JFrame. Is it possible to make objects of these pictures in my main class and use them in my JFrame? something like my code below.
public class JFrameTesting { public static void main(String[] args) { Image ImageVariable = Toolkit.getDefaultToolkit().getImage("C:1.jpg"); MyJFrame f = new MyJFrame(); f.setTitle("Drawing Graphics in Frames");
I have one question that suppose I am designing a Swing applications and I am using JFrame as Top level container.
So what is best
1)first Extends that class like
public class A Extends JFrame { //Do all stuff with Top Level container with gui }
2)Or design like this from this source
[URL] ....
package components; import java.awt.*; import java.awt.event.*; import javax.swing.*; /* TopLevelDemo.java requires no other files. */ public class TopLevelDemo { /** * Create the GUI and show it. For thread safety, this method should be invoked from the event-dispatching thread. */ private static void createAndShowGUI() { //Create and set up the window.
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 want to know if I can get the entire log4j.properties file constructed in Java code. I am not talking about configuring the logger using Java code.I have a logger that is already configured using a file. I want to get access to either Logger or LogManager (any other?) class and print the current configuration that is in memory.
import javax.swing.JFrame; public class groupingTest { public static void main (String[] args) { groupWindow test = new groupWindow();
[Code]....
At the start of the groupWindow it turns yellow and it says "The serializable class groupWindow does not declare a static final serialVersionUID field of type long".
