Declaring Enums - Could Not Find Or Load Main Class
Feb 25, 2014
I've just started, so right now I'm reading about declaring enums, the book lists the following code
enum CoffeeSize {
//8,10 & 16 are passed to the constuctor
BIG(6), HUGE(10), OVERWHELMING(16);
CoffeeSize(int ounces){ //constructor
this.ounces = ounces;
[Code] .....
I'm assuming that code to be in a same file since enums can be declared within and outside a class, so I saved it into a file named "Coffee.java", it compiles just fine from command line but when I try to execute "java Coffee" it throws "Error: Could not find or load main class Coffee"...
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 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.
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";
I'm trying to run a java program from cmd. I'm using Windows 8, java version "1.8_0_20". I've got two classes, the main class called Middleware and a secondary class, called WorkerThread, of which the main class is using functions. I've successfully compiled both .java files with javac, and created the .class file. So all files are in the same folder. However, when I attempt to run the main class with java Middleware, I get the error message: "Error: Could not find or load main class". Here's the main class:
package middleware; import java.net.*; import java.util.concurrent.*; public class Middleware { //Number of threads serving clients. private static int nr_threads = 5; private static int portNr = 6789; private static ServerSocket welcomeSocket; private static ExecutorService executor;
[code]....
My code compiles and runs fine in eclipse but on the console, I'm having troubles.
I'm getting an error trying to run a welcome app from a book. I've looked at the FAQs and can't seem to solve the issue. I'm guessing my path and/or classpath are not right. Here's my path environment variable.
I was trying to write my own version of the game SimpleDotCom from Head First Java. I have two files:
Game.java: package project_01; public class Game{ byte hitCount = 0; String result = "miss"; int counter = 0; String checkGuess(int[] location,int userGuess){
[Code] .....
The two files are in the same directory, "project_01" and the CLASSPATH environment variable is set to ".;". The game compiled but when I tried launching it with "java GameTester" it returned the error : Could not find or load main class GameTester. I know my game is horrible and probably extremely buggy but I'll fix all the bugs, etc. later, right now I just need to get it to run.
My problem is that I can compile a java HelloWorld program using javac HelloWorld.java but I cannot run the program using java HelloWorld. I didn't create the code it was developed by a professional programmer. My assignment is to compile and run, so that I see the output.
I'm new to this java stuff and when I go to notepad++ and this keeps coming up when I try to compile it: "Error: Could not find or load main class HelloWorld" what it means...
I am trying to understand how package(directory structure) and JAR files work interchangeably. From my understanding JAR is a package file format typically used to aggregate many Java classes. Since many classes are usually contained inside a package, I should be able to create a JAR file from a package, and use them interchangeably. A single JAR file is easier to handle then multiple classes and folders.
To test my understanding of the concept, I am working with the following project structure,
package BookPackage; public class Book{ private String bookname; public Book(String str){ bookname = str; } public String getBookName(){ return bookname; } }
and BookDemo.java contains the following code,
import BookPackage.Book; class BookDemo{ public static void main(String ... args){ Book b = new Book("Lord of the Rings"); System.out.println(b.getBookName()); } }
From the development_directory, I used the following commands to compile and run the project,
...and it compiles and works as expected.Now, I will try to convert the BookPackage folder(package) into single jar file for portability, and I am using the following command to do that,development_directory/ jar -cf bookpkg.jar BookPackage ...this command generates the bookpkg.jar file.
I am going to remove the BookPackage folder to see if bookpkg.jar file really works as a replacement for the BookPackage directory structure.
After removal of BookPackage folder, the development_directory structure looks like this,
I 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
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 am trying to put together an encryption/decryption application that will essentially accept a sentence that is submitted, and spit out the encrypted version and then switch it back to the correct sentence. I have been told to nest my information in the class (rather than the main), but am having difficulty actually understanding how to do this. The error that Eclipse is throwing me is also that it "could not find the main class." Here is my code:
import java.util.Arrays; import java.util.Random; public class encryptingWords { public static void main(String[] args) { final int ALPHASIZE = 26; final char[] Lalpha =
I currently use Eclipse to maintain our Java application. I recently upgraded from Java 6 to Java 7. I updated my Eclipse projects to use the Java 7 .jar files. I can run the application from Eclipse via the Run Configuration.
I can also run the Ant build and it completes successfully. When I install the application on my desktop, I receive the "Java Virtual Machine Launcher: Could not find main class..." error. My CLASSPATH is set to ".".
How do you declare methods for a class within the class whilst objects of the class are declared else where?
Say for instance, I have a main class Wall, and another class called Clock, and because they are both GUI based, I want to put a Clock on the Wall, so I have declared an instance object of Clock in the Wall class (Wall extends JFrame, and Clock extends JPanel).
I now want to have methods such as setClock, resetClock in the Clock class, but im having trouble in being able to refer to the Clock object thats been declared in the Wall class.
Is this possible? Or am I trying to do something thats not possible? Or maybe I've missed something really obvious?
I am wondering if there is a way in jave to use enums WITHIN a class (without creating a separate enum class) without using private static final. Something like as folows:
class My Class { myEnum {ACTIVE, INACTIVE, PENDING}; }
I am trying to declare fields as protected String custom.field.1096; in my java class but it does not allow me. Can I not declare the field as above? Is there any workaround to achieve this?
Within my program I allow users to write their own code to be executed. I then save that code in a .java file and then compile. This gives me a .java file and a .class file within the same package in the src folder. However, the compilation process also creates a .class file in the build folder. When the user edits their code and then re-runs it, the .class file in the build folder does not get updated with the new data, but the .class in the src folder does.
What I want to do is to execute the .class file in the src folder and not the build folder. So far I have the following method, but that somehow refers to the .class file in the build folder:
public void runMethod(String packageFilePath, String className){ try{ URI fileURI = new URI("file:/src/uk/learningAid/UserInputs/"); URL url = fileURI.toURL(); URL[] urls = new URL[]{url};
