Running Encryption / Decryption Application - Could Not Find Main Class
Jun 23, 2014
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 ".".
I want to create a java program that can be encrypt-decrypt alphabet from characters . Which is the shifting of the alphabet is starting from the the first character to increase 4 and 5 increased in the second character, increasing 6 at the third character, and so on..
Then when one of the characters increasement is more than the ascii code of 'z', that character will decrease from the variable i from the loop. This is the output of the program that i want:
I need to encrypt/decrypt file contents using RSA . But the default nature of RSA I could not upload files larger than 177 bytes for key length 1024 bytes . How it can avoid , I look it for a 100 times yet...
I have to write an encryption/decryption program for a sentence entered by the user that uses arrays. Here is my code so far. I'm kind of lost on what to do next in the code.
import java.util.Scanner;
/*Program that encrypts then decrypts a sentence Encryption */ public class Encryption extends java.swing.JFrame{
For this week's assignment, I am supposed to create a java program that encrypt's a user's sentence, outputs the encrypted message, then decrypts the message, outputting the user's original message.
This is what I have so far. It doesn't compile the last few lines since that is not correct Java syntax.
Java Code:
import java.util.Scanner; import java.io.*; public class Decrypter { public static void main(String[] args) { String sentence; final char REAL_ALPHA[] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
[Code] .....
So you can see I have "realAlpha" which are regular letters of the alphabet, and "codeAlpha" which are the letters I want to encrypt with. I want 'a' equal to 'z,' 'b' equal to 'y', 'c' equal to 'x' and so forth in that sort of reverse order, you know? So the word "apple" would encrypt into "zkkov."
I am stuck as to how to replace the letters in this way. You can see I tried fumbling with sentence.replace to switch the letters out between the two arrays. Also, I only barely understand arrays.
I am creating 2 different java codes for encryption and decryption separately based on RSA algorithm. The codes also involve swings for GUI. The problem with these codes are that my string is getting encrypted but after decrypting it,i do not get the string rather i get string of random numbers and alphabets. I am posting both the codes.
Encryption code:
import java.math.BigInteger; import java.util.Random; import java.io.*; import javax.swing.*; import java.awt.*; import java.awt.event.*; public class cipher implements ActionListener
[Code] ....
Now the decryption code
import java.math.BigInteger; import java.util.Random; import java.io.*; import javax.swing.*; import java.awt.*; import java.awt.event.*; public class decipher implements ActionListener
[Code] ....
The screenshots for respective codes are as attachments ....
I've written most of the code (along with another classmate) to get this to work, but I can't seem to return the encrypted value. I'm also trying to figure out how to separate the digits (or if I'm supposed to) to make the numbers encrypted. The main kicker is that we have to be using methods to return the final values. Everything compiles, (It compiles, but no results really.)
A company wants to transmit data over the telephone, but they are concerned that their phones may be tapped. All of their data is transmitted as four-digit integers. They have asked you to write a program that will encrypt their data so that it may be transmitted more securely. Your program should read a four-digit integer number and encrypt it as follows: Replace each digit by the remainder after (the sum of that digit plus 7) is divided by 10. Then, swap the first digit with the third, and swap the second digit with the fourth. Then print the encrypted integer. Do the encryption in a method and send the encrypted number back to main.
Here are the method headers: public static int encrypt(int num) // Takes num as a parameter and returns the encrypted value public static int getnum() // gets one number from the user Example: If the user enters 1234 they should see: 0189
import java.util.Scanner; //Needed for Scanner class public class LNFI_LNFI_program2 { public static void main(String[] args) { getnum(); //Calls for getnum() method
I made a software using Netbeans and javaswing. Accidently i deleted my main file which contains my main class and main method. Just to test, i tried to compile and run and it worked but the style of my buttons and windows has changed. So, what happened? How can i change the style of my programs?
//File Accidently deleted package time; public class Time { public static void main( String[] args ) { Window wdow = new Window(); wdow.setVisible( true ); } }
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 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
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.
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'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'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 a problem with running my hello world aplication. Here is the code.
public class HelloWorld { public static void mаin(String[] args) { System.out.println("Hello world!"); } }
It compiles fine. But I get an exception when I try to run it.Here is the error message I'm getting:
Exception in thread "main" java.lang.NoSuchMethodException: HelloWorld.main([Ljava.lang.String;) at java.lang.Class.getMethod(Class.java:1605) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:113)
I am integrating Struts hibernate tiles and spring configuration project. While running give me exception as
Apr 15, 2015 7:16:10 PM org.apache.catalina.core.AprLifecycleListener init INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:Program FilesJavajre1.8.0_40in;C:WindowsSunJavain;C:Windowssystem32;C:Windows;C:/Program Files/Java/jre1.8.0_40/bin/server;C:/Program Files/Java/jre1.8.0_40/bin;C:/Program Files/Java/jre1.8.0_40/lib/amd64;C:ProgramDataOracleJavajavapath;C:Program Files (x86)NVIDIA CorporationPhysXCommon;C:Program Files (x86)InteliCLS Client;C:Program FilesInteliCLS Client;C:Windowssystem32;C:Windows;C:WindowsSystem32Wbem;C:WindowsSystem32WindowsPowerShellv1.0;C:Program FilesMySQLMySQL Server
