I am trying to figure out how to get information back from a different method.
Basically I want to write a program to create a car, but I want to be able to add features based on user our put (V6 versus V8, Color choice, etc), but I want each one to be broken out into their own method but I am unsure of how to call from the main method and return the variable (engineSize = V8, color = blue, etc).
I'd like to know how to return a new array, I wrote in a method below the main method. I want to print the array but system.out.print doesn't work for arrays apparently. What structure i should use?
View Replies View RelatedI have to write a method called censor that gets an array of strings from the user as an argument and then returns an array of strings that contains all of the original strings in the same order except those with length of 4. For example if cat, dog, moose, lazy, with was entered, then it would return the exact same thing except for the words with and lazy.
Currently, my code so far just prints [Ljava.lang.String;@38cfdf and im stuck.
import java.util.Scanner;
public class censorProgram {
public static void main (String args[]){
Scanner input = new Scanner (System.in);
System.out.println ("How many words would you like to enter?");
int lineOfText = input.nextInt();
[Code] ....
I have to make new string array in the method and return words without four letters in the main method
I'm trying to return an array back to main. The array returned to main should contain the reversed random numbers array. I believe I have the array correctly reversed within the 'reverseArray' method. I'm trying to send this array back to main, but it appears to contain empty data (a bunch of zeros).
Java Code:
class ArrToMain {
public static void main(String[] args) {
final int NUMBER_OF_ELEMENTS = 1000;
double[] numbers = new double [NUMBER_OF_ELEMENTS];
//Invoke initialize method
initialize(numbers);
[Code] ......
Passing Information to a Method or a Constructor
They show a line of code that goes like this:
public Polygon polygonFrom(Point[] corners) {
// method body goes here
}
So from what I understand this is a constructor method for a Polygon object from the Polygon class. What I dont get is the name of the method polygonFrom()
Shouldn't a constructor for a Polygon just have the same name as the class? Because from earlier examples in the tutorial it seems to me that this is what has been done
For example:
public Bicycle(int startCadence, int startSpeed, int startGear) {
gear = startGear;
cadence = startCadence;
speed = startSpeed;
}
This program contains a superclass and a subclass that will gather the following information from the user:
name, address, phone number, and customer number.
Everything works fine except that I have to create a boolean method in this program that is required to determine based on user input whether they want to be added to a mailing list.
I cannot get this method to work with main, each time it is called it will always return the value but main will constantly read the last statement (else, where it will read "not wanting to be added to the mailing list).
The only way I can get this part of the program to work is by adding an equals method in main that ignores the case, but I am required to write a boolean method so this is not allowed.
Superclass:
public class Person
{
private String name;
private String address;
private String phoneNum;
public Person(String pName, String add, String number)
{
name = pName;
address = add;
[Code] ...
I've been putting together an addressbook and try to work on some idea but I have hit a bit of a wal early on, and Im sure the problem is easy to resolve, I just can't get the old brain to do it.At present I have 5 classes
PersonDetailsAdressDetailsAddressBookAddressBookGUIEnterDetailsPanel
I have taken EnterDetailsPanel out of the main GUI code, as I plan, or had planned on using additional JPanels for the other options of the application until I got stuck. What I want the EnterDetails panel to do, which it does so far is to have the user enter all of their information and when the button is pressed it will then create a PersonDetails object and here is where my problem is. how to get the object from the panel back across to the GUI which initalises the AddressBook class in the constructor and add it to the List via an addDetails() method.
If I create a quick method in the AddressBookGUI class I can add the object to the List fine, I'm guessing this is because I have created a new instance of the AddressBook in here already via the constructor, however if I add an AddressBook reference in the EnterDetailsPanel I get a nullpointerexception for the opposite because it's not been created in there.These are what most of the classes do so far.
PersonDetails has a reference to the AddressDetails and holds all information for that person.AddressBook contains a List that accepts PersonDetails and has methods to add/remove the person.AddressBookGUI creates a new instance of the AddressBook class along with the general gui things. EnterDetailsPanel is added to JTabbedPane in the GUI class and allows the user to enter their details and submit those via a button which will then create a new PersonDetails object that I am trying to get added to the AddressBook class List
I have a website which requires login. After I enter username and password and click login button, a new page is loaded. In that page I have a username in the right up corner. When the user clicks logout button, Session.Clear() method is called and also Response.Redirect(" to login page "). It works OK, but the problem appears when I then click Back button in the browser. It gets me back to previous page with the username in the right up corner. Insted, I would like to show message asking user to enter password again so he can login properly.
What should i do at client side???
how to have an application restart if the user inputs an incorrect integer in a JOptionPane question? I know how to do it with the Scanner class but nothing I do seems to work. This is the beginning of my code:
import javax.swing.JOptionPane;
public class Pay {
public static void main(String[] args) {
String level = JOptionPane.showInputDialog("Please select your skill level: 1, 2, or 3");
int levelPick = Integer.parseInt(level);
[code]...
I'm using the class below to encrypt and decrypt data in my program. It works rather well with the exception that I can't for the mind of me get the recreation of the key to work. When the program runs the first time, it creates a key and saves it to Data.txt. This part works fine, and there are no errors, the encryption and decryption works until I reload the program and it tries to recreate the key using the String in the .txt.
read = loadFile.readline();
byte[] data = read.getBytes("UTF-8");
key = new SecretKeySpec(data, 0, data.length, "PBEWithMD5AndDES");
I've looked at:
java - convert Byte Array to Secret Key - Stack Overflow
java - Converted secret key into bytes, how to convert it back to secrect key? - Stack Overflow
and a number of other sites which didn't work, both of these however suggested the key = new SecretKeySpec. The actual key became: "[B@79fe3f51". Whereas the recreated key became: "[B@3e1d1648".So they are close, but not the same.I create the original key like this:
key = SecretKeyFactory.getInstance("PBEWithMD5AndDES").generateSecret(keySpec);
Encryption.java:
public class Encryption {
public Cipher dcipher, ecipher;
// Responsible for setting, initializing this object's encrypter and
// decrypter Chipher instances
Encryption(String passPhrase) {
[code]....
This piece of java software I am responsible for is running throughout numerous locations in my country, there is only 1 location which has trouble with the dates being displayed incorrectly, birthdates of clients are displayed as a day earlier. It seems pretty safe to say it is a problem on their end... But still, they're asking me for an explanation as to why java would treat a date differently in this rare case.
The date (a birthdate) comes from an oracle database, it is a date without a time (trunced date). It enters the application as a member of the client-class, it is NOT being set or changed after that. It goes through several layers in the application, then ends up in a GUI class which unwraps it from the "client"-object and puts a SimpleDateFormat (new SimpleDateFormat("dd-MM-yyyy")) on it. My first and only hunch was the timezone settings, but that seems to be OK!
I'm stuck with the following error message when i try to convert a String to XML and back to a String.
Exception in thread "main" org.w3c.dom.DOMException: WRONG_DOCUMENT_ERR: A node is used in a different document than the one that created it.
at com.sun.org.apache.xerces.internal.dom.ParentNode.internalInsertBefore(Unknown Source)
at com.sun.org.apache.xerces.internal.dom.ParentNode.insertBefore(Unknown Source)
at com.sun.org.apache.xerces.internal.dom.NodeImpl.appendChild(Unknown Source)
at com.innovatrail.consulting.xml.XMLTEST2.main(XMLTEST2.java:66)
Below is my Java code snippet: The code syntactically correct except line 66. If you comment out line 66 in the source code, everything works just fine. The XML representation of my input string is denoted by INPUT 1 and that of my output string is denoted by OUTPUT 2.
package com.Test.xml;
import java.io.ByteArrayInputStream;
import java.io.StringWriter;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
[Code] ....
INPUT 1:
<Collection>
<BookList>
<Book>
<Title>Wonder Man
</Title>
<Author>John Smith
</Author>
<Category>Fiction
[Code] .....
OUTPUT 2:
<Collection>
<Book>
<Title>Wonder Man</Title>
<Author>John Smith</Author>
<Category>Fiction</Category>
[Code] ....
When we have a jsf form to store clients in a ddbb for example and the backing bean is in session scope.... Lets think of a user that requests 3 times the xhtml view with the form to store 3 clients.
1) If we dont reset the backing bean each time the form is processed, he would see the values he sent beforea and it doesnt have much sense, right?
2) Here there is an example of clearing form after submitting : [URL] ...... Clearing the form after submititng is a common practice for the reason of the statement 1, right?
3 ) What is the best or normal approach to reset values in a form? when the user requests it or done automatically by the application after processing a form?
4) Are there known issues about resetting or not resetting the values in a form bean?
Inside a While Loop (While Loop begins if a condition is True) I have an If Statement, the else part of the statement assigns False to the condition I mentioned earlier.
But I've tried de-bugging and even when the code goes through the else part of the statement, firstly it returns False but then it returns to the beginning of the loop as True again.
I am looking for a good and reliable library to read a string to construct a list of Integers, Doubles, Booleans, etc. This library should be robust enough to handle faulty input from an inexperienced user.
Example:
input: "1, 2, 3, 4"
output List<Integer> [1, 2, 3, 4]
input: "1, 2, 3.6, 4"
output List<Double> [1.0, 2.0, 3.6, 4.0]
input: "true, true, false"
output List<Boolean> [true, true, false]
input: "[1, 2, 3]"
output List<Integer> [1, 2, 3]
input: "(1, 2, 3)"
output List<Integer> [1, 2, 3]
It would be really nice if such a library would already exist.
How to go back to main menu and terminate a program?
I just want a Simple code.
Ok, so I am relatively new to datagrams etc. I have three projects set up right now: Client, Client2, and Server, which all interact with each other to send coordinates of player1 and player2 back and forth (X, Y, this is in 2D space not 3D). I have everything set up perfectly except for one problem: I can only send the X coordinate back and forth for each player. I am getting the weirdest error, a parsing error. The way I communicate is I have everything sent back and forth in one string. Then I use the .split() function to turn that string into an array that contains the x and y coordinates. I've done several tests and to no avail. Here's my code:
Server:
Java Code:
package theGame;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import javax.swing.JOptionPane;
public class Main {
static String p1X;
static String p1Y;
[Code] ....
Lines 177 on Client1 and 172 on client2 are where the debugger is saying that I parsed wrong.
Also, if your are going to test this you will need to have the LWJGL libraries in your build path.
Life Cycle Call back methods(init(), destroy(),...) are not transactional by default and expecting this in coming EJB releases (EJB 3.x / EJB 4.x). I was expecting next EJB release along with Java 8, but it stays at 3.2
View Replies View RelatedI am messing around with a Swing application and am a bit stuck as to how to join the front and back ends.This is the code for the DataManager class which is responsible for loading and saving objects and interfacing with rest of the system. The data I need displayed comes from a .txt file in the applications directory. I need to show certain aspects of the data in the JComboBoxes in the GUI class.
Java Code:
package programdataapplication;
import java.io.*;
import java.util.*;
public class DataManager {
[code]....
how I can join back-end and GUI classes.
How do you remove from an ArrayList at a particular index then add back to that same index without the removal causing the ArrayList to compensate for the loss of them item and moving the empty space to the end of the array list?I've tried:
public void dischargePatient(int bedNumber) {
if (bedNumber < beds.size()) {
beds.remove(bedNumber);
}
}
But this moves the bed at bedNumber to the end of the ArrayList after removing the patient from the bed. How do I keep it at bedNumber?
When a thread completes its execution, it will be destroyed.In Java thread pool implemenation, how does threads come back to ready state after executing the task.?
View Replies View Relatedget updated bean property in javascript function. This function I am calling from <a4j: commandbutton> this button is having actionListner, which is updatin bean property based on some User selection. When this action is completed then I am calling javascript function in oncomplete. But that javascript function is not taking updated bean value, it is always taking first value.I can't use hidden text as there are some drop downs which User will selct and then hit commandbutton which will update bean property.
<div align="center">
<a4j:commandButton
value="#{msgs.notification_searchNotificationReportLbl}"
id="searchNotificationRptBtn" styleClass="controlButtonActive"
actionListener="#{dashboardCtrl.loadOTVsubmit}"
oncomplete="drawChart();"
[code]....
I have started coding recently and been working on a simple java timer. My problem is that the button does not show any response even though an action has been done via actionlistener.
Example: When I press the "Start Timing" button, it should start timing and output the counter to Static Timer but instead of doing that, it does nothing.
The important bits are under Timer code and Button Start Timing. Is their something that I'm missing?
//--- All imports have been handled ---
public class GUI {
double counter = 1;
double inputA = 1;
int delay = 1000;
Timer timer = new Timer(delay, null);
[Code] ....
I am getting Web Page Expired error while clicking the back button of the browser, after submitting a form. The form method is POST. ( I have to keep it that way). I tried this code
<%session.setHeader("Cache-Control", "no-cache");
response.setHeader("Cache-Control", "no-store");
response.setDateHeader("Expires", 0);
response.setHeader("Pragma", "no-cache");
%>
In my jsp. Still it is not working. I also tried
<script language="JavaScript" type="text/javascript">
window.history.forward(1);
</script>
i have one html page ,inside html radio button and 3 textboxes and one submit button ->action->SampleServlet.java-> from here again come back to html page with checked radio buttton value and text box value. I dont want to click back button in this case, html page to servlet->here i have to call back to my html page with checked radio button and text box value .
I tried response.redirect(original.html)-->i cant able to display checked radio button and textbox value also tried requestdispatcher forward/include,html page comes newly from starting but i dont want it,i want to view in html page with checked radio button and text box value.
I have a jsp page that generate a hashtable and display its key-value pairs back to the browser. The problem is that it takes on an average about 15 minutes to build this hashtable, and as a result, I always get a timeout error. What can I do to avoid getting the timeout error without changing the server configuration for timeout
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