When To Use Multiple Main Methods
Apr 7, 2014
I am confused when it is proper to use an application with multiple entry points, or I guess an application with multiple interconnected modules. I have a network application (Netty) as well as a web application (spring). I can bundle them together, in effect tightly coupling them together, or I can modularize them to operate interdependently of each other while still working together to make the application whole.
Is there any specific reason for making an application a single entity vs multiple entities? Is it "desired" to have a self contained application (eg. One main method)?
View Replies
ADVERTISEMENT
Sep 30, 2014
This current one is to calculate a planes holding pattern. I have to write a method to prompt user to enter speed in knots, then it converts it to km/hr. Another method to calc. pattern width using the speed, another method to calc. pattern length, than a main method which would call and print out the speed in knots, speed in km, pattern width and length.My current problem is on the second method. It works in that I can enter the values and it gives me the correct answers, however it's asking me to enter the speed twice, instead of just once. Anything I try just results in errors and won't compile.
import java.util.Scanner ;
//main method
public class TitleRemoved {
public static void main(String[] args) {
double airSpeedKm = airSpeedOts () ;
System.out.println("That speed is " + airSpeedKm + " km/hr.") ;
[code].....
I want my code to not only work, but be organized and easily readable as well, so I want to avoid bad habits.
View Replies
View Related
May 7, 2015
I can call a child method from a main method. If I have a parent called "Assessment", a child called "Quiz", and another child called "test". Can I instantiate an object like Assessment a = new test(); and call a method in test.
I know the method can be called if I instantiate the test t = new test() but that defeats the purpose of inheritance...
View Replies
View Related
Nov 1, 2014
I was reading the book, "Head First Java" and it was talking about how there may be multiple classes in a large application, but there will be only one main method.how does it work that way? How can you have multiple classes, but only one main method?
View Replies
View Related
Mar 25, 2015
I am trying to make a 2d graphical animation using the java swing classes in order to make a frame. I had a basic version working when all of the code was under the main method, but when I moved some into another method it broke it. With y understanding of java my code should work as I create a variable of the method containing the code and then assign the size and exit button. However this causes many problems such as my BeaconFrame method informing me that it is unused when I have used it. Here is my code:
import javax.swing.*;
import java.awt.*;
public class BelishaBeacon {
public void BeaconFrame() {
JFrame frame = new JFrame();
JPanel panel1 = new JPanel();
[code]....
View Replies
View Related
Jan 15, 2015
a. Create an application named ArithmeticMethods whose main() method holds two integer variables. Assign values to the variables. In turn, pass each value to methods named displayNumberPlus10(), displayNumberPlus100(), and displayNumberPlus1000(). Create each method to perform the task its name implies.
b. Modify the ArithmeticMethods class to accept the values of the two integers from a user at the keyboard.
View Replies
View Related
Sep 13, 2014
Is it possible to have multiple methods in one class?And can I use the Scanner in methods other than the main method?
View Replies
View Related
Dec 19, 2014
For reference I am programming Java in BlueJ. I am fairly new to the language and I am having trouble with sorting.
I am trying to call / test all of the 5 sorting methods (at the same time) in the main class. To be specific, the sorted list has to technically outputted 5 times.
I figured out how to call / test Quicksort:
Sorting.quickSort(friends, 0, friends.length-1);
But the others are not working correctly. Specifically these:
Sorting.mergeSort(friends, 0, friends.length-1);
Sorting.PbubbleSort(friends, 0, friends.length-1);
Sorting.PinsertionSort(friends, 0, friends.length-1);
Sorting.selectionSort(friends, 0, friends.length-1);
For reference, this is the output when it is not sorted:
Smith, John 610-555-7384
Barnes, Sarah215-555-3827
Riley, Mark 733-555-2969
Getz, Laura 663-555-3984
Smith, Larry464-555-3489
Phelps, Frank322-555-2284
Grant, Marsha243-555-2837
This is the output when it is sorted:
Barnes, Sarah215-555-3827
Getz, Laura 663-555-3984
Grant, Marsha243-555-2837
Phelps, Frank322-555-2284
Riley, Mark 733-555-2969
Smith, John 610-555-7384
Smith, Larry464-555-3489
This is the class Sorting, which I should note is all correct:
public class Sorting{
/**
* Swaps to elements in an array. Used by various sorting algorithms.
*
* @param data the array in which the elements are swapped
* @param index1 the index of the first element to be swapped
* @param index2 the index of the second element to be swapped
*/
private static <T extends Comparable<? super T>> void swap(T[] data,
int index1, int index2){
T temp = data[index1];
data[index1] = data[index2];
[Code]...
This is the Main class in which I am supposed to call the sorting methods, SortPhoneList:
public class SortPhoneList{
/**
* Creates an array of Contact objects, sorts them, then prints
* them.
*/
public static void main (String[] args){
Contact[] friends = new Contact[7];
friends[0] = new Contact ("John", "Smith", "610-555-7384");
friends[1] = new Contact ("Sarah", "Barnes", "215-555-3827");
[Code]...
View Replies
View Related
Apr 17, 2015
I am assigned to create a program "Simpletron" that the only language understands it is Simpletron Machine Language or SML. I figured out the most but I get the message "No main methods, applets, or MIDlets found in file" when compiling the program. I pasted my program so that you can see.
//A Simpletron computer simulator */
import javax.swing.*;
import java.text.DecimalFormat;
import java.awt.*;
import java.awt.event.*;
[code]....
View Replies
View Related
Jul 6, 2014
I'm working on an assignment where I need to take radius and height from the user to use with the methods in class Cylinder. I have to use radius and height as input parameters in the methods that calculate: Base area, lateral area, total area, and volume. But when I use height and radius as input parameters then it just prints zeros for all calculated values. When I remove (double radius) from the method it works just fine. So my question is how can I get this to work with radius/height as input parameters? Or am I just misunderstanding will they still be input parameters even if I don't have it written as (double radius) in the method?
import java.util.Scanner;
class Cylinder{
double radius = 0.0;
double height = 0.0;
double baseArea;
double lateralArea;
double totalArea;
double volume;
[Code]...
View Replies
View Related
Jul 13, 2014
I have a class, which communicates with database via SQL queries. But one queries don't produce any ResultSet, while other queries do. Now I'm facing situation, where I have two methods, one which executes queries with return values and other which executes queries without return values:
public ResultSet executeQueryWithReturn(String query){
try{
return executeWithReturn(query);
}catch(Exception e){
e.printStackTrace();
[Code] .....
But I see few problems here: 1) Method can return null, (I read in book Clean Code, that people should avoid return null) Another issue - boolean value breaks the rule that method should do only one thing.
Maybe there is a better option? or maybe I should forget these two issues here for readability?
View Replies
View Related
Apr 9, 2015
I'm trying to build a program that will output what will ultimately look like a simple mario level turned on its side. As part of my output I need the user to define what mario looks like. I do this using Scanner and save the input to String mario. When I try to use that variable in another method it gives me troubles.
import java.util.Scanner;
public class Mario2
{
public static void mario() {
//user defines mario
String mario = ">->O";
Scanner keys = new Scanner(System.in);
System.out.println("What does mario look like?");
mario = keys.next();
System.out.println("Mario now looks like: " + mario);
[code]....
View Replies
View Related
Oct 21, 2014
package Experimentation;
import javax.swing.*;
import java.awt.event.*;
public class SimpleGUI1B implements ActionListener {
JButton button;
public static void main(String[] args) {
SimpleGUI1B gui = new SimpleGUI1B();
gui.go();
[code]...
This is a program from Head First Java! since main is static it shouldn't be able to call non-static methods because statics do not use any instance variable values but in the above program we're call a non-static method go() how is it possible?
View Replies
View Related
Dec 8, 2014
I have i am trying to implement tooltip through javascript, like when we click on an image link tooltip should be displayed and it should have close button/ close image to close that tooltip.like the same way i will have multiple images on page, when ever i click on the images all tooltips should be displayed on the page when ever i want to close that then only it should close through close button on tooltip.can we do it through java script or will go for jquery.
View Replies
View Related
May 5, 2015
I'm very new to Java, and I am creating a program that takes multiple user input to create one face. I have a class for the eyes, nose, lips, and headshape. For some reason, my program is not drawing the graphics. ***for question purposes, I have only included my head shape class and my test class****
my "test" class:
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class FaceTest
{
public static void main(String[] args)
{
String head = JOptionPane.showInputDialog("Would you like a circle, square, rectangle shaped head?: ");
[Code] ....
View Replies
View Related
Sep 15, 2014
what is different between void main() and public void main()
View Replies
View Related
Jul 23, 2014
I'm trying to make a TBG (Text Based Game) in Java for Android. Now, when I try to run it, it says No Main Method to run this program. The compiler also checks the program and tell me there are no errors.
View Replies
View Related
Apr 3, 2014
Why we do not need main in applet .....
View Replies
View Related
Mar 10, 2014
import java.io.*;
import java.util.List;
import java.util.ArrayList;
public class ListOfNumbers {
try
[code]....
i tried this code in BlueJ IDE.it told me i had an illegal beginning for "try".am i not supposed to use try for main methods?
View Replies
View Related
Mar 25, 2014
What happened when we use main() as a private. . . . .???????
View Replies
View Related
Jan 4, 2015
I've made a class called Car with a method which will tell me a category for the engine size regarding the actual size (which I've included in the main just so I could see if it works) but everytime I test it I get an error.
public class Car {
public String b;
public String c;
public double es;
public double cs;
public String getCategory() {
if (es < 1.3)
[Code] ....
Figured it out. Was missing parenthesis on audiCar.getCategory();
View Replies
View Related
Oct 1, 2014
in java why main method is always static in nature...
View Replies
View Related
Oct 12, 2014
I am writing a code where in the first method the question will ask whats your favorite website. for example www.javaprogrammingforums.com...when it outputs it will read just "javaprogrammingforums" without the www. and the .com.
Because the program will ask a series of questions in the main, I would like website question to be returned to the main. Here is my code, and what can I do?
import java.util.Scanner;
public class chapter3 {
public static String website(Scanner kb) {
String website;
System.out.println("What is your favorite website?");
website = kb.next();
[Code] ......
View Replies
View Related
Apr 17, 2014
How do I call a class within the main. For example, this is what i have in my code right now. I am trying to call the class BlackJackGame.
package blackjack;
public class BlackJack {
public BlackJack() {
BlackJackGame();
}
}
View Replies
View Related
Oct 14, 2014
public static void main(String[] args) {
Scanner kb = new Scanner(System.in);
int hours = getHours(kb);
char major = getMajor(kb);
[code]....
I'm trying to return a char c,o, or x if that is their "major code" that the scanner grabbed.
View Replies
View Related
Aug 7, 2014
I have 3 source file below
//Hello.java
public interface Hello {
public void sayHello();
}
//Espanol.java
public class Espanol implements Hello {
[Code] ....
View Replies
View Related
