How To Find Out Minimum JRE Requirement For Java Program
Jan 26, 2014
I finished a game in Java and sent it to a friend. Launching the program in my computer worked just fine.
But he got this error : "Could not find the main classs: Main. program will exit"
My JRE version is the most updated one. His JRE was version 1.6. He updated his JRE, and the problem was solved.
This is a bit worrying for me, because as far as I know, 1.6 isn't a very old version of the JRE. It's not the most recent one, but not that old.
This is worrying because I'm planning on sending my game to a lot of friends, and trying to distribute it on the internet.
A lot of people don't have the most updated JRE. And they are mostly non-programmers, so I can't expect them to update to the newest version of Java upon downloading my game. They might not know what Java is, even though they got it on their computer, and upon receiving an error, they'll just give up on the game.
If my game wouldn't work with a significantly old JRE, that would be reasonable. It's part of the nature of working with Java. But the fact that a relatively updated JRE, 1.6, doesn't work with my game, is worrying.
*(Please note: My game isn't implementing anything "special". Swing and KeyBindings are the 'newest' additions to Java that I can think of inside my game)*.
In short, I'd like to know that my game works on most of the computers it tries to run on. Knowing that it doesn't work on a relatively new JRE, is worrying.
So I have two questions:
1. Is it normal, for a Java program, to have such "high" demands for the JRE version? Do a lot of Java games demand at least version 1.6 of the JRE? Is this common?
2. How can I find out the minimum JRE version requirement for my program? Is there a methodical way to do this, or do I just have to go through all the libraries I use in my game and figure out what's the JRE release version for each one?
I'm required to create a program that finds the minimum value in an Array of integers.
Here is my approach :
public class Person { public static void main(String [ ] args){ int theArray[]=new int [10]; int result = 0; for (int i:theArray){ if (i < Integer.MAX_VALUE)
[Code]...
I can't really progress from this position. I keep getting told to change the return type to int on main method, then when i do it says change it to void..
I am using the following code: But doesn't work fine. I try to find the Minimum spanning and print it out from house to which hose.
public class MinimumSpanning { public static void main(String[] args) { // [][] edge= are price between each hose edgs. int [][] edge= {{0,7,9,12,0,0,0}, {7,0,0,10,0,0,0}, {10,0,0,12,0,0,0}, {12,10,12,0,11,0,10}, {0,0,0,11,0,4,8}, {0,0,0,0,4,0,6}, {0,0,0,10,8,6,0}};
[code]....
It should only print one time. Example between K to L prints many time.
I was given some code by a professor to add some features to as part of an assignment. However, the code itself doesn't seem to work.
import java.util.HashSet; import java.util.InputMismatchException; import java.util.PriorityQueue; import java.util.Scanner; import java.util.Set; public class DijkstraPriorityQueue
[Code] ....
The method to find minimum distance is nonfunctional...I receive an error that the types are incompatible. I can't do the assignment if the base code doesn't work to begin with...
I want to Write a program that calculates the minimum fixed monthly payment needed in order pay off a credit card balance.
the Amount is 3,500 the annual rate is 9.9%, the minimum payment is 2% a month. the fixed payment is 150.
By a fixed monthly payment, we mean a single number which does not change each month, but instead is a constant amount that will be paid each month.
The program should print out :
payment information: new balance total ....... current payment due .......
if you make minimum payment (2%) you will pay of in .... months and you Will end up paying an estimated total of $........
if you make the fixed rate payment, you will pay of in .... months and you Will end up paying an estimated total of $........ and you will save $........
I am working on this rental program and got stuck in the last part. The program is about renting a car; after completing the rent process it displays the user who spent maximum and minimum rent. This is where I can't proceed. The program displays maximum values for both max and min. Here's the code I have written:
import java.util.Scanner; // program uses Scanner public class CarRentalTest { public static void main( String[] args ) { System.out.println("Welcome to Rental Portal"); Scanner input = new Scanner( System.in ); // create Scanner to obtain input from command window CarRental details=new CarRental();
class GenericQueue<E> { private LinkedList<E> list = new LinkedList<E>(); public void push(E element) { list.addFirst(element); } public E pull() { return list.removeLast();
[code]...
Is a constructor required to create an object, if one of its instance or class variables haven't been instantiated? Like private String string;
I need to write a java program to find the index of the element whose value is the sum of the remaining elements. Recently I have been asked this question in an Interview which I couldnt solve properly.
Write a program that prompts the user to enter an integer m and find the smallest integer n such that m * n is a perfect square. (Hint: Store all smallest factors of m into an array list. n is the product of the factors that appear an odd number of times in the array list. For example, consider m = 90, store the factors 2, 3, 3, 5 in an array list. 2 and 5 appear an odd number of time in the array list. So, n is 10.)
so far my program is just like this.
import java.lang.Math; import java.util.Scanner; public class PerfectSquare { public static void main(String[] args) { Scanner m = new Scanner(System.in); int Fint;
[Code] .....
how do i make the program find the smallest integer n?
I have made a program which finds the number of occurrence of the words. It is as follows :
public class B { public static void main(String[] args) { Map<String, Integer> mp = new LinkedHashMap<String, Integer>(); String s = "This is me tarun ohri This"; Scanner p = new Scanner(s); int i = 0;
[Code] .....
Output is coming {This=0, is=1, me=1, tarun=1, ohri=1}
I have to write a program that find the sum of two numbers 62 and 99 and stores them in a variable named total. However, I have one error that I just can't get rid of and can't tell what it is. I'm using jGrasp and here's what it says:
Programming Challenge #5.java:14: error: class SumofTwoNumbs is public, should be declared in a file named SumofTwoNumbs.java public class SumofTwoNumbs { ^ 1 error ----jGRASP wedge2: exit code for process is 1. ----jGRASP: operation complete.
and here: is my code:
import java.util.Scanner; /* * 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. */ /** // This program has variable of several of the integer types. public class SumofTwoNumbs { public static void main(String[] args) {
I wrote a program that find adjacent value for -1 .ex:
input 1 3 3 1 2 2 1 1 -1 5 5 0
output 1
code: /* * 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 javaapplication1; import java.util.Scanner;
I have to write a program the calculates the MPG and display's the result on the screen. However, I have three errors I just can't seem to figure out. jGrasp points to the following error, but doesn't tell me what it is:
Programming Challenge #9.java:34: error: cannot find symbol gallons = keyboard.nextInt(); ^ symbol: variable keyboard location: class MPG 3 errors
----jGRASP wedge2: exit code for process is 1. ----jGRASP: operation complete.
My code is as follows:
import java.util.Scanner; /* * 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. */
// This program has variable of several of the integer types. public class MPG { public static void main(String[] args) {
im trying to do a program to find if numbers are consecutive or not! if they are consecutive i need a true as a return and a false when they are not... i did this program and im sure i did something wrong because i keep only true returns ..
Example: (3,5,7) (1,2,2) (7,7,9) should return a false! Java Code: import java.util.*; public class Consecutive{ public static void main (String [] args){ Scanner console= new Scanner(System.in); System.out.println("Enter three numbers"); String numbers = console.nextLine(); System.out.println( "The numbers (" + numbers + ") is '" + consecutive( numbers ) + "'" ); }//end of main
I just created a Hello World program in Notepad, but command prompt still can't find it even when ran as administrator. I've even tried to use command line to run Hello World programs I've created with Eclipse but it still doesn't work. Here's proof I have JDK setup as PATH:
I've even tried having the JRE as path but that still doesn't solve my problem. I'm really trying to learn Java programming but this problem is holding me back.
I can't get the code to compile for the driver every time i get an error message saying
SudokuCheckerTest.java:28: error: cannot find symbol foo.displayGrid(grid); ^ symbol: variable grid location: class SudokuCheckerTest SudokuCheckerTest.java:29: error: cannot find symbol foo.getGrid(grid);
[Code] .....
4 errors
Java Code :
import java.util.Scanner; public class SudokuChecker{ public SudokuChecker(){ // displays intro code and initializes the array grid as well as using method calls. Scanner in = new Scanner(System.in); int [][] grid = new int [4][4]; displayGrid(grid);
This is my first java program,i am using eclipse IDE-----
package day1.example;
public class MyFirstJava {
/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("hi"); } }
When i saved it,it shows no error.when i run it then a pop-up says "could not find the main class.the program will exit" and in the console it says---
java.lang.UnsupportedClassVersionError: day1/example/MyFirstJava : Unsupported major.minor version 51.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$000(Unknown Source)
I want to find the prime palindrome numbers less that a given number by my program. Here is my code, I am trying to find the method to solve the errors when I compile it. It said variable a might not have been initialized in line 41,62,86.
import java.util.Scanner; public class Lab5{ public static void main (String[] args){ System.out.println("Please input a number"); Scanner Input=new Scanner(System.in); int num = Input.nextInt();
I am writing a payroll program .The program generates random PPS numbers and then takes in users information and calculates the salary accordingly. I am using netbeans and my code is showing errors on line 18 and 42 ("cannot find symbol")on the code for grossPay(). The program seems to crash after a new PPS number is generated and will not run.
package sd_assg_2; import java.util.Arrays; import java.util.Random; import javax.swing.JOptionPane; public class SD_ASSG_2 { public static void main(String[] args) { String[] newPPs = getPPSno();
The second message dialog result is always 0 ... i want to find the minimum grade...
import javax.swing.*; import java.util.Arrays; public class Parrarrapapa{ public static void main (String[]args){ String length = JOptionPane.showInputDialog("Number of students");