I am new to java and still learning. I am trying to execute the code below which compiles successfully, but getting the following error:"Exception in thread "main" java.lang.NoSuchMethodError: main"
Code:
class Dog{
int size;
String name;
String breed;
void bark(){
System.out.println("woof woof");
}
}
class DogTestDrive{
[code]....
import java.io.Console;
public class Introductions{
public static void main(String[] args){
Console console = System.console();
console.printf("Hello!My name is ---");
}
}
Output :-
Compiling Introductions.java.......
-----------OUTPUT-----------
Exception in thread "main" java.lang.NullPointerException
at Introductions.main(Introductions.java:5)
[Finished in 2.2s with exit code 1]
exception in thread main java.lang.nullpointerexception code 45 and code 116
the lines are highlighted and no the code tags did not show up when I uploaded the file.
I typed '[code]' below:
Java Code: /**
This program demostrates rainfall for a year
*/
[Code].....
I use Eclipse IDE
public class Emp {
private String name;
private String jobTitle;
public void setName(String nameIn){
name=nameIn;
[Code] ....
<terminated> TestClass
Exception in thread "main" java.util.NoSuchElementException: No line found
at java.util.Scanner.nextLine(Unknown Source)
at TestClass.payOneEmp(TestClass.java:21)
at TestClass.main(TestClass.java:13)
I am working on a program that will allow a user to input grades for a class of four students who have taken two tests. Based on the grades entered, the program will calculate the averages of the two tests for each student and display it along with their respected letter grades.
Now I can get the program to compile successfully, but after inputting the grades in, I get the error message saying that it cannot format given object as a number. I am using 4 arrays to execute this program and maybe that's why I'm having the trouble? I'm not sure because I am still fairly new at this stuff and can't sen to resolve it.
I was having problems for a while and then finally got excited when I got it to compile without any errors and now I'm getting an error inside my program. All I need to do is format the numbers of the grades into something like: 000, and each of the averages as 000.0. I understand how to do it because I have done it in another program I've done in the past. I just don't know how to fix this error that is coming up.
here is my code:
import java.util.Scanner;
import java.text.DecimalFormat;
public class TestAverage
{
/**
* A program that will store and process 2 test scores for a class of 4 students.
* The program will prompt for the test scores as shown above in the sample run.
* After all the data is entered,the program will display the score for test 1, test 2 .
* The average of the 2 tests and the letter grade for the class for each student in a tabular format.
*
*
[code]....
My program is user input 20 char and the program will print the most common. So I use another int arr which count the number appears in the original array. i know its not so Effective but I don't know why it run but it stop in the middle. I got this code :
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 20
at Ex2.common(Ex2.java:39)
at Ex2.main(Ex2.java:23)
import java.util.Scanner;
class Ex2 {
public static void main(String[] arg) {
Scanner reader = new Scanner (System.in);
char[] arr=new char[20];
System.out.println("Please enter 20 chars:");
for (int i=0;i<20;i++)
[Code] ....
I'm currently learning about Swing but I can't get my head round this piece of the code. Here is a simplified gui (not interested in the gui part but the execution)
public class SwingDemo implements ActionListener {
SwingDemo(){
JFrame jfrm = new JFrame("Simple gui pro");
//rest of code
public static void main(String[] args) {
new SwingDemo();
}
I get the above, create a new instance of SwingDemo in the main thread which starts up the gui through the constructor. However, then the tutorial says that I should avoid doing the above but do this instead:
public class SwingDemo implements ActionListener {
SwingDemo(){
JFrame jfrm = new JFrame("Simple gui pro");
//rest of code
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() { //why do this instead?
public void run(){
new SwingDemo();
}
});
}
}
Reading, it talks about an event-dispatching thread which has completely lost me... Why not just instantiate the object directly instead of creating another thread?
I have two classes, where main class is simple with only main function in it. Another class extends Thread and there's couple of functions I want to execute from main class.
Problem: I try to get other.shut() to be run in main class catch() block, after I have stopped the other class's running thread (e.g. by ctrl+c).
I think I need to somehow "pass" the exception from other class to main class so it goes to the catch block?
Code for main class:
Java Code:
public class MainClass {
public static void main(String[] arguments) {
OtherClass other = new OtherClass();
try {
other.exec();
} catch (Exception e) {
other.shut();
[Code] .....
I am designing the game of Snake but it crashes after i added the checkScore() method.
package com.complex.snake;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.*;
import javax.swing.JOptionPane;
[Code] .....
The error i get is : Exception in thread "Thread-3" java.lang.ArrayIndexOutOfBoundsException: 1
I'm working on an assignment for my java class and I am currently stuck with an error/exception,
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:864)
at java.util.Scanner.next(Scanner.java:1485)
at java.util.Scanner.nextInt(Scanner.java:2117)
at java.util.Scanner.nextInt(Scanner.java:2076)
at BabyNames.search(BabyNames.java:45)
at BabyNames.main(BabyNames.java:20)
I input my name, which is able to get my name from the names.txt, however after that, it hits an exception and does not go further on.Also please use the names,
JIMMY
JIMMIE
JIMMU
JIMI
(All can be lowered case), because I am unable to upload the full file for it is very big.
import java.util.*;
import java.awt.*;
import java.io.*;
//Jimmy
//Programming Assignment #6: Baby Names
//This program is going to scan a file with data
//about names and their popularity starting from the 1890's
//and will display their popularity over the years in 10 intervals.
[code]...
The following code generates an array out of bounds exception
int[] myArray1 = new int[5];
for(int j = 0; j < myArray1.length; j++)
{
myArray1[j] = 10;
System.out.println("myArray1["+j+"] : " + myArray1[j]);
}
for (int i : myArray1) {
System.out.println("Blah myArray1["+i+"] : " + myArray1[i]);
}
The exception
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 10
at Tutorial2.main(Tutorial2.java:40)
Class A{
Public static synchronized void main(String args[]){
Thread t= new thread();
t.start();
Sysout("hi");
t.wait(1000);
Sysout("hello");
}}
Illegal state monitor exception. Why?
For this program, I have to run a slot machine. It runs until right before the do while loop and then I receive the error: Exception in thread "main" java.util.InputMismatch.Exception. Searching around, someone said it was a scanner error and adding a call keyboard.nextLine(); fixes the problem- however with that I receive the same error.
Code :
import java.util.Scanner;
import java.util.Random;
import java.io.*;
public class SlotMachineSimulation
{
public static void main(String[] args) throws IOException
{
int number;
[Code] .....
The error I get when I execute my java file.
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!”);
[code]....
im having an issue with the 3rd thread that are supposed to merge the two sorted sub arrays , i pass the 2 subarrays to my runnable function sortlist and they are renamed IntSortList 1 and 2 and th1.start() and th1.join() are called and it works fine, but then i have another runnable constructor that takes IntSortList 1 and 2 but it does take a runnable. below is the code in my main,
Runnable InSortlist1 = new sortList(data2p1);
Runnable InSortlist1 = new sortList(data2p1);
Thread th1 = new Thread (IntSortlist1);
Thread th2 = new Thread (IntSortlist2);
try
{
th1.start();
th1.join();
[code]....
class A extends Thread
{
String str;
public void run( )
{
//random stuff
}
}
[Code]....
How to access one thread from another thread?
View Replies View RelatedI 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.
Doesn't matter now, I solved it but I don't know how to delete a thread...
View Replies View RelatedI want to try and run a thread that starts running on start and quits after pressing a key.I cant seem to detect keypresses. ci cant seem to add code: Post denied. New posts are limited by number of URLs it may contain and checked if it doesn't contain forbidden words.
its just a code snippit without links or anything..this is a small part... but how do i add a keyListener in here that listends to a random key?The class implements KeyListener and the overrided method "keyPressed" sets the isRunning boolean to false... but the keyPressed method is never executed.
public static void main(String[] args) {
Thread thread = new Thread() {
public void run() {
while(isRunning){
System.out.println("running");
try {
sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
};
thread.start();
}
how to start a new thread
public class pracDraw extends JFrame {
private Color red=Color.red;
public int i;
private Color white = Color.white;
JPanel pr=new JPanel();
JTextField t=new JTextField();
[code]....
If u run it you can see that the JTextField (t1) is drawn on the panel along the line but it does so with a gray border. How do i eliminate that grey border and only draw the text field along the line and finally make the text field green after it reaches the end of line?
import java.awt.Graphics;
import javax.swing.JFrame;
class node{
node(int a,node next){
this.a=a;this.next=next;
[Code] ....
The code was ran not right, I want it's result is: 1 2 3 4 5 and delay(1000) every time that it prints a number
Example: 1 (delay(1000)) 2 (delay(1000)) ....
And the paint must do that
i know how to interrupt a thread in java but somehow it is not working.
My Application looks like this
public class MyThread {
public static void main(String[] args) {
Thread testThread = new Thread(new GreatThread());
testThread.start();
[Code]....
I always read that interrupting a Thread is so much better than the .stop method but somehow the interrupt method don't work?
I have a program ive been working on and it works, but the flags in the runnables seem to shift the output down 1. for instance i commented playa3. start(); to see whats going on, if i just run playa1 i got no issues, as soon as i enable playa2, i get this output:
Game continues...
Dealer places King and Queen on the table.
Game continues...
Dealer places Queen and Ace on the table.
Player one with 'Ace' places his card on the table.
Player one with 'Ace' wins the current deal.
King Queen
Game continues...
Dealer places Queen and King on the table.
Player two with 'King' places his card on the table.
Player two with 'King' wins the current deal.
Queen Ace
the second time the dealer deals, player one places his cards on the table when he was supposed to do that for the first deal which he didnt. the last line there, (king queen) is just a print statement that is referring to the dealers hand that, that iteration is responding too. below is my code, i
import java.util.*;
import java.io.*;
import java.lang.*;
public class P5
{
public static int i, count, dealerFirstCard, dealerSecondCard, player1, player2, player3;
public static String cardSet [] = {"Ace","King", "Queen"};
public static volatile boolean dealerFinished= false;
public static volatile boolean playersFinished= false;
[code]....
have written a new class that contains a thread.
From within that thread I try to call a method from within the same class the contain the thread. This method is not being called. I have confirmed that that section of code is being executed in the thread.
If you look at the following code, the thread being run is called MainThread ln 114, and the method it calls that is not being executed is called onprogressTime() ln 105;
package com.example.scott.coloursquares;
import android.content.Context;
import android.graphics.BitmapFactory;
[Code]....