In my main method I am trying to create a Timer, but when I put new Timer(1000,listener) the constructor is not defined. It is when there is nothing in it. I find this super weird because in all my other programs this does not happen. I looked at the documentation and can't see what I am doing wrong, so I turn here.
I know that I am not 100% comprehending try/catch blocks, but after scouring message boards, forums, and Oracle, I still can't pick out where I am going wrong.
I have a ValidateInput class where I am trying to check that a String only has letters. If not, then throw an exception message via JOptionPane. I created my own NonLetterException class. When I call the method containing the try/catch Eclipse gives me an Unhandled Exception Type error.
in main() ValidateInput validate = new ValidateInput(); String name = "error"; for(int x = 0; x < 1;){ name = JOptionPane.showInputDialog("Welcome. What is your name?"); boolean isItName = validate.stringInput(name); //error appears at validate.stringInput if(isItName)
[code]....
Aren't I handling it in the try/catch? What did I miss?
Also, I have have tried the NonLetterException class as nested in ValidatedInput, but also not nested. To me nested makes more sense. I have never nested classes before, but it makes sense to me because I am not using this exception in other parts of my program.
I'm having an issue when I try to define a variable in a JSP scriptlet, and then in a separate scriptlet on the same page attempt to use the variable. It looks like it goes out of scope.
I also cannot reference a variable from a servlet in a JSP expression tag. So I've had to write the entire page basically in one scriptlet.
Any Technique that will decide which one of the fields (Integer, Address, DOB, String, Float) are user defined type. (An outsider class should used that will identify the Java classes and the user-defined classes.)
I am currently in the middle of a certification program and doing quite well but now I am a bit stuck.
I have two classes in the program, one defines a box based on drawRectangle, the other is a simple Applet to display the box. This is the Box - Class :
import java.awt.Color; import java.awt.Graphics; public class Box { private int upperLeftX, upperLeftY, height, width; private Color boxColor;
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);
this code won't compile because selected row must be declared as final because of it being defined outside the window listener. Is their anyway around this? If I make it final the first time that the variable is called it keeps it starting value until the GUI is closed.
butEdit.addActionListener (new ActionListener () { @Override public void actionPerformed (java.awt.event.ActionEvent evt) { int selectedRow = table.getSelectedRow (); final String [] values = custTableModel.getRowValues (selectedRow);
I am trying to remove the duplicate elements from ArrayList using .contains() if elements are primitive datatype it works but user-defined datatype does not work.
public class UserBean { String name; String address; public String getName() { return name;
Created a java.sql.connection object. Refering those obj inside public void run() { } If i declare as final inside a method, i can't refer those outside method due to scope. Cannot refer to a non-final variable dbConnObj inside an inner class defined in a different method...
so i'm following a java tutorial from the book and it has a few challenge questions. and i'm stucked on one. i think i just don't understand what is it that its asking me. heres the question, Write a statement that reads a user's input integer into the defined variable, and a second statement that prints the integer. assuming scanner is given, and i checked my heading code is ok.
Scanner scnr = new Scanner(System.in); int userNum = 0; System.out.println("What is the product of 8 time 2"); userNum = scnr.nextInt();
I'm using a PrimeFaces UploadedFile xhtml page to select a csv file to read and write using a managed bean (SuperCSVParser.java). The file is read and written to an entity class which then persists the data to a database. The application works fine if I specify a file path on the physical server and select a csv file on that file path. But for the production version I want the user to select ANY file name from ANY directory on their local system.
I know about the FacesContext methods and I've looked at some methods from the java.io File class. Most of these methods are about getting the path from the server, where I want to 'pass' the path String from the client machine to allow the uploaded file to go through. When I try with the below code I get:
java.io.FileNotFoundException: data.csv (The system cannot find the file specified)
I'd like to know what I'm doing as I prefer not to explicitly declare a path in the final app. I'm almost sure that's possible.
I am working on a project involving a class that has the attributes of one of its inner classes. Now, if possible, I would like to make it so that the inner class is not visible outside of the class. Also, some of the functional mechanics require that the class be an instance of the nested inner class (it extends the inner class). The following code snippet demonstrates the situation.
public class A extends A.B { public static class B { //ideally I would like this to be private/protected. } }
When I try to compile this program, I get the error message "Cyclical inheritance involving A." This error does not make much sense because, since the inner class "B" is static, it requires no instance of "A" (it does not inherit from "A" or uses it). My question is "Is it possible to do something similar to this structure?" I have searched many forums in search of the answer but have not found anything that attempts to explain it. The closest problem that I have found is one relating to the inheritance of a nested inner class from another class. I would like to express that the problem that I am having involves a class defined within the inheriting class.
