Why To Get NoClassDefFoundError Exception When Didn't Change Anything
Feb 23, 2014
My program was working fine and then without changing anything, it has started throwing me a "Exception in thread "main" java. lang. NoClass Def FoundError: medina/client/ClientGameFrame". I'm dumbfounded as to how this can just suddenly appear after I've been working on this program all week. My research has pointed out that it must be my class paths but as far as I know, the class paths are fine....and why would it suddenly stop working if it was my class paths ?
I have just been trying to compile in netbeans and that's when the error occurs, though I just tried packaging to a jar and the jar works fine...though why not in netbeans?
Exception in thread "main" java.lang.NullPointerExceptionat DogTestDrive.main(DogTestDrive.java:19)
Here is the source
class Dog { int size; String name; void bark () { if (size < 60) { System.out.println("Woof woof");
[code]....
Some background: I'm reading "Head first Java 2nd edition" and I'm going through the examples which is showing me how to change the state of an object. The original code looks like the code below, however the previous chapter went over creating array's of an object, so I created an array of the object "Dog" and wanted to re-write it this way. To my understanding, it should work but it's giving me that error when I execute it. The error itself isn't very clear, if I could get a line number pointed to, that would work.
class Dog { int size; String name; void bark() { if (size > 60) { System.out.println(“Wooof! Wooof!”); } else if (size > 14) { System.out.println(“Ruff! Ruff!”); } else { System.out.println(“Yip! Yip!”);
I am facing NoClassDefFoundError with one of the java standard platform class (java.text.DigitList$1)
java.text.DigitList class is part of rt.jar so it should not create any issue as such.
I am using Java 1.6.0_06
StackTrace: Unhandled exception java.lang.NoClassDefFoundError: java/text/DigitList$1 at java.text.DigitList.shouldRoundUp(DigitList.java:4 11) at java.text.DigitList.round(DigitList.java:363) at java.text.DigitList.set(DigitList.java:351) at java.text.DigitList.set(DigitList.java:272) at java.text.DecimalFormat.format(DecimalFormat.java: 584) at java.text.DecimalFormat.format(DecimalFormat.java: 507) at java.text.NumberFormat.format(NumberFormat.java:26 9)
I was trying to execute the following program and the multiplication worked but the division didn't work.
import java.util.Scanner; public class BodyMassIndex { public static void main(String[] args) { // Prompt the user for weight and height // Create a scanner Scanner input = new Scanner (System.in); System.out.println("Please enter your weight in pounds"); int weight = input.nextInt(); System.out.println("Please enter your height in inches"); int height = input.nextInt (); double BMI = weight * (0.45359237)/ (height * 0.0254)*(height * 0.0254); // the weight * (0.45359237) executed but it wasn't divided by (height * 0.0254)*(height * 0.0254) System.out.println ("Your BMI is "+BMI);
I extracted a jar file and decompiled one of the classes using jad in order to made a small edit (the original jar was looking to load an image file in the current directory, I replaced the current directory with an environmental variable). I went and recompiled that class. It complained that it cannot find some swt classes, so I downloaded swt.jar for Linux from the Eclipse website and specified the classpath to contain it. It compiled fine and I repacked the jar file. But when I tried to execute it I got:
Java Code: Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/swt/widgets/Decorations at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2531) at java.lang.Class.getMethod0(Class.java:2774) at java.lang.Class.getMethod(Class.java:1663)
[code]...
I do not get the same error when I execute the original jar file (that complains that it cannot find the image file unless I put the image in the directory I execute it from). I even tried putting swt.jar in the classpath during execution:
I was giving a quick skim to some tutorials on the internet where I have found the exception that is handled is also declared in the throws clause of the method wrapping the try-catch block. For a code representation consider the following:
public void methodName() throws IOException { try { ... } catch (IOException ex) { .... TODO handle exception }
Right, so I got this program. It takes input from the user and assigns it to fields on an object. But, it's meant to check the users input. If the user enters bad input, it's supposed to throw this exception. For each of these exceptions, theres a class specifically for it.
public class PayrollDemo { public static void main(String[] args) { Payroll pr = new Payroll ("Test Name", 234); System.out.println("Current Employee Information. "); System.out.println("Name: " + pr.getName()); System.out.println("ID: " + pr.getID()); System.out.println("Hourly Pay Rate: " + pr.getHourlyPayRate());
[Code] ....
And this is the exception class.
public class InvalidNameException extends Exception { /** No-arg constructor */ public InvalidNameException() { super("Invalid name"); } }
PayrollDemo.java:43: error: cannot find symbol InvalidNameException.InvalidNameException(); ^ symbol: method InvalidNameException() location: class InvalidNameException 1 error
It's just meant to tell the user that they entered an invalid value, which would mean if they entered an empty string instead of a name.
I have a strange problems. Perhaps some of you already have had this problem before.
I have method which is suppose to check if the itemstate has changed. It ONLY works ONCE?
Thereafter, it does not matter how many times I changed the selection of the ComboBox.
Basically I have two Comboboxes.
1. If Combobox 1 is selected (e.g. Dogs, Cats) 2. Then get information from what ever the item from ComboBox 1 is selected, and display on ComboBox 2. (Dog Name, Cat Name etc)
E.g.
So If I selected Dogs on Combobox 1 Then display the Dog Names on Combobox 2. If I then change and select Cats on Combobox 1, then display Cat Names on ComboBox 2.
I need to change the program below to an "array"....
public class RecursiveFibonacci { public int fibonacci(int n) { int result; if (n == 1 || n == 2) result = 1; else { int n1 = fibonacci(n-1); int n2 = fibonacci(n-2);
Write a program that asks the user for the low and high integer in a range of integers. The program then asks the user for integers to be added up. The program computes two sums:
The sum of integers that are in the range (inclusive), and the sum of integers that are outside of the range. The user signals the end of input with a 0.
Your output should look like this:
Sample input/output
In-range Adder Low end of range: 20 High end of range: 50 Enter data: 21 Enter data: 60 Enter data: 49 Enter data: 30 Enter data: 91 Enter data: 0 Sum of in range values: 100 Sum of out of range values: 151
This is my assignment and below is my code.
import java.util.Scanner; class InRangeAdder { public static void main(String[] args) { Scanner scan = new Scanner (System.in); int low, high, data=1, rangesum=0, outrangesum=0;
[Code] ....
The problem is that the program simply gives an output of 0 for both "rangesum" and "outrangesum". I don't quite understand why that is. Also i have a quick question, the program needs me to end the program when the value of data is 0 but in order to initialize it I need to give it a value. Usually I would give it a value of 0 like I have for rangesum and outrangesum but if I do the program does not run till the loop as it considers the value of data to be 0 and ends the program right away. What would be a work around to this and when do I need to have a value to initialize an integer? for example, I do not need a value for low and high. Is this because the program recognizes that a value is going to be defined but cannot do that for the other integers as they are inside a loop?
I am very much new to Java. I have just started learning event handling. Currently I am learning about Key Events. And am learning by doing. Well that is how one could learn anything in fact. I want to write a program in which the currently loaded image in the panel of a frame changes upon a key press say "Enter" or any other key.
I'm programming in school using Netbeans and we've just started with graphical programming (i.e JPanel, JClass, JFrame). This is my first assignment and the purpose of this program is that when you press the mouse you will fill 4 circles with diffrent colors. I've managed to draw 4 circles with diffrent colors but I want my cursor to change color simultaneously. Here's my code so far ....
//Java klass "Klick" public class Klick { //Medlemsvariabler. private int x = 0; private int y = 0; private int r = 1; public int antal = Rityta.antalKlick;
I am currently working on a small java programm. I use netbeans for it. And obviously I am new to java.
Basically its a calculator that change the input value into another value: like 10 € into whatever $ and same with Inch and Centimeters.
Therefore I need a second jDialog Form where i can change the factors for the calculator and start the calculator again.
Here is my problem: I can open the second Dialog but if I want to change the factor it doesn't change the value in the variable and the second calculator frame is with the old factors. It seems the double variable isn't working globally
I'm a first timer at jsf, and right now I'm learning how to use ajax in jsf. i got a problem when i click a command link i want to change in a content, but when i run my web and i click the command link it didn't do anything. This is the source :
<?xml version="1.0" encoding="UTF-8"?> <!-- To change this license header, choose License Headers in Project Properties. To change this template file, choose Tools | Templates and open the template in the editor. --> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"
[Code] ....
In this code when i click the Home button it suppose to change the ouput text to a string that store in my bean. This is my bean:
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package UI; import javax.faces.bean.ManagedBean; import javax.faces.bean.RequestScoped;
[Code] .....
At first the output text value is the same as the string i store in the bean. but when i click the commandlink, it didn't do anything, is there something wrong with my code?
I read in a book that when you change the value of a method parameter that's a boolean or other basic datatype within the method it only is changed within the method and remains the same outside. I want to know if there is some way for me to actually change it within the method. For example:
public class Change { void convert(boolean x, boolean y, boolean z) { //i want to set x,y, and z to false in this x = false; y = false; z = false;
[code]...
I want to put in part1, part2, and part3 when i call the method than i want them to be set to false within the method. The specific reason i asked this question was because im trying to code a battleship and i have a subroutine class with a method that when its called it checks if a ship has been sunk. If the there was a sink than the method will set a ton of boolean variables to false.
Just to clarify, I want something like this:
void convert(thing1,thing2,thing3,thing4) { //some code here that sets thing1,thing2,thing3, and thing4 to false } // than in main: boolean test1 = true; boolean test2 = true;
I have a GUI with a menu to do various options. However I want to change that menu to use buttons instead. I'm working with JSwing components and I'm a little familiar with the JButton function, but I don't know how to convert the menu to a button. I think I'll have to remove the menu completely..anyway I tried to start with the file menu but the compiler says no suitable method found for setForeground(javax.swing.JMenu). Why is it giving me an error related to JMenu when I'm using Jbutton objects? Can I not use JButton objects inside a menubar scope? I'll bold the area it highlighted:
When in panel2 i type something in the search bar and then i move mouse cursor to panel1 and try to edit a JTextField input for example as in the picture 0.0 nothing happens but the mouse cursor is correctly show up in the JTextField.. What seems to solve the problem is to click anywhere outside of the application window.. but of course this is not a solution !
GoodEmployee is defined who has ALL the following properties:
He should be married. He should have 2 or less than 2 children. His middle name should start with "k" but not end with "e" The last name should have more than 4 characters The character "a" should appear in the last name at least two times. The name of one of his children should be "Raja"
isMarried true if the employee is married. noOfChild the number of children of the employee. middleName the middle name of the employee lastName the last name of the employee. childNames the array of the names of the children of the employee
In my jsp page , functionality is their to change the status of the employee, so i want that if i click on activate it should change the link to the deactivate and when i click on deactivate it should change to activate. How can i do that?
I am quite familiar with using JOptionPane and its various displayXDialog() methods and reasonably familiar with changing fonts.
I have a JOptionPane.displayMessageDialog() that is working fine but I decided to make the font larger.
I found an example from which I coded:
Font font = UIManager.getFont("OptionPane.font"); UIManager.put("OptionPane.font", new Font(font.getName(), font.getStyle(), 24)); font = UIManager.getFont("OptionPane.font"); JOptionPane.showMessageDialog(this, "Welcome to Mover", "About Mover", -1); // no icon
After the UIManager.getFont() call after the UIManager.put() call, font shows the new font size of 24, but the showMessageDialog() dialog still has the default font.
And yes I understand that, when this works, it will affect every JOptionPane in my program.
I also tried:
Font font = UIManager.getFont("OptionPane.font"); JOptionPane message = new JOptionPane("Welcome to Mover", JOptionPane.INFORMATION_MESSAGE); JDialog dlg = message.createDialog("About Mover");
[Code] ....
This gave me a dialog with the default font and an unwanted icon.
So I tried
// both Font font = UIManager.getFont("Dialog.font"); // and Font font = UIManager.getFont("JDialog.font");
and planned to use that font in my setFont() call but font was null.
