What Two Aspects Define Objects
Sep 5, 2014I have googled but could not really find what I was looking for or an answer I could understand. Also, I am a visual learner so any example.
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Define Main Method
Apr 26, 2014this is my program error occured run time,but compile sucessfully
{error msg-Error: Main method not found in class helloworldapp.HelloWorldApp, please define the main method as:
public static void main(String[] args)}
class HelloWorldApp
{
private int empno;
private float salary;
void setHelloWorldApp()
{
empno=12;
salary=1200;
[code]....
Swing/AWT/SWT :: Define Header Of JTable And Set A Value?
Feb 2, 2015I want to create a JTable which "Analysis","Date" and "Price" the names of columns in header. Here's a piece of my code :
String sql = "Select name, Price from analysis_tab where name ='" + idclicked + "'";
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd");
Date date = new Date();
PreparedStatement preparestate = database.con.prepareStatement(sql);
ResultSet rs = preparestate.executeQuery();
So, the value of Analysis and Price were stored in my Data Base, and the Date get the value of the current day. How can i create this JTable and how can i set the value into it ?
Define Array From Form Input?
Jul 17, 2014how do I define array elements using input?
<script language="Javascript">
/*//////////////////////////////////data base array/////////////////////////////////////*/
var array ga[]; /*guest array*/
ga[0] = "Joe";
ga[1] = Buck;
ga[2] = 11;
ga[3] = Pine;
ga[4] = Street;
ga[5] = Apt;
[code]....
Map To Define Latitude And Longitude Of The Centre
Mar 1, 2014I am new to Java and i am doing an assignment to identify Class and Attributes from below example. identify 7 classes and its attributes from this scenario:
ABC Maps Maker produces electronic maps for global positioning systems. Every map needs to define the latitude and longitude of the centre of the map, together with the length and breadth of the map. A map also has a name, and a set of geographical features.
A geographical feature is something noticeable in a a map; e.g., a hill, or valley. Among the types of features are the following: trace features, track features and tract features. All features have a name that is displayed on the map next to the feature.
A trace feature has a coordinate point to indicate its location relative to the centre of the map.
Broadcasting stations, mountain peaks, and transmission towers, are examples of trace features. Every trace feature has a description associated with it. Examples of track features include roads, railways and rivers. Each track feature has a list of points that define its course, and a line pattern. The line pattern specifies the colour, and the thickness.
Like a track feature, a tract feature also has set of points, except that when drawn on the map, the last point is linked to the first point to enclose a complete region. Additionally, it has a fill pattern which incorporates essentially a colour. Recall that there is a class, Point, in the java.awt package - this can be used to hold the co-ordinate of a point
Class:
Attributes:
Class:
Attributes:
Class:
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Class:
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Can User Define Array Variable?
Feb 10, 2015I am writing a program to store books (Book class) in volumes (Volume class). Within the main class (DemoVolume) I am doing a couple different things. I want to ask the user if they are creating a new array, if yes, I was to create a new array with a variable names assigned by the user. Is this possible? The reason is I want to allow the user to be able to search their library of volumes. If no, then the user will enter the book information and I will assign it to an array unassignedVolume that will contain individual books. I would also like to create book objects that are defined with the book name, if this is possible. I'm just messing around and trying to deepen my understanding of JAVA. My main issue is how to allow the user to title the volume (array variable).
import java.util.Scanner;
public class DemoVolume {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String [] volume, unassignedVolume;
Volume volumeOne = new Volume("JAVA", 3, volume);
[Code] ......
Swing/AWT/SWT :: Trying To Define Visible JTable But Failing
Apr 4, 2014I'm trying to make a simple table with JTable class by reading the following tutorial but when try to see my JTable my program doesn't show me nothing! What i'm doing wrong?
[Code] .....
import javax.swing.JScrollPane;
import javax.swing.JTable;
public class MyFirstTable {
public static void main( String[] args ) {
String[] columnNames = {"First Name",
"Last Name",
[Code] ......
JavaFX 2.0 :: How To Define Indeterminate CheckBox In TableView
Jun 6, 2014I would like to defined a TableView with a column containing a CheckBox.
This can be done with an instruction like this : myColum.setCellFactory(CheckBoxTableCell.forTableColumn(myColumn);
The problem is how to specify that the displayed CheckBox is an indeterminate one ?
Define Variable When User Has To Type Into Program So It Can Be Converted
Sep 23, 2014I don't understand how i'm supposed to define a variable when the user has to type it into the program so it can be converted. This program i'm working on is supposed to convert from meters to feet (meter = feet * 0.305) but the user has to type in the meters they want converted. how do i solve the problem that keeps coming up that says "variable meter symbol cant be found" ? I keep trying different lines to no avail
public class Lab2
{
public static void main(String[] args) {
double feet = meter * 0.305;
double meter = feet/0.305;
System.out.println("Enter in feet for conversion to meters");
meter = meter * 0.305;
[Code] .....
Define All Local Variables And Method Parameters As Final?
May 16, 2015I am using findbugs and PMD as a code analyser. I am keep getting warnings to use local variables and method parameters as final.
I want to know if its a good practice to keep them final or what to do?
Sometime i have a private method which is 1 line longer. Sometime it is annoying to use final.
JavaFX 2.0 :: How To Define Cell In The Table By Table Event
Mar 23, 2015How to define Cell in the table by table event?
I need to process one component drag to the table. I misunderstand, how I can see to which Cell fall the component. I tried to use Event and Mouse event handlers in my custom Cell, but they do not work. I can copy the drag event to the table and table handles it, but how to get needed Cell I cant understand.
Copying Data Objects To Serializable Objects
Jul 27, 2014I am currently working on a project where I need to return data from a database over RMI to a client who requests it. Some of the fields in the Data Object can not be seen by the client so I need to create another object to send over the network instead. The method I use is this...
public static SerializableObject createSerializableObjectFromDataObject(DataObject dataObject){
SerializableObject serializableObject = new SerializableObject();
serializableObject.setField(dataObject.getField());
serializableObject.setAnotherField(dataObject.getAnotherField());
return serializableObject;
}
Is there a better way of doing this? I am creating many subclasses DataObject which all require this static method to be implemented and I can't push it into the superclass because each one needs custom behaviour.
How String Objects Are Different From Other Objects
Jan 23, 2015how String objects are different from other objects
part 1:
// creating two objects
Dog mydog1 = new Dog();
Dog mydog2 = new Dog();
// comparing the reference variables
if( mydog1 == mydog2){
System.out.println(" The reference variables refer the same object ");
}
else {
System.out.println(" They refer to different objects ");
}
The above code works as I understand objects , it prints "They refer to different objects " to the screen.
Part - 2
// creating two objects ( I beleive, pls correct me if i am wrong )
String a = "haai";
String b = "haai";
if( a == b){
System.out.println(" Reference variables refer to same object");
When i run the above code it prints that a and b refer same object , I don't understand how they refer to same object when i didn't assign " String b = a; ". My question is did java just create one object and stored the same reference values to a and b .
Update XML Using DOM Objects
Sep 29, 2014I have a requirement to insert the data into xml file . I have used DOM class for doing this. Below is my xml file
<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<deployments>
<applications>
<application>
<name> PCMH</name>
[Code] ....
The thing is if SITA is the name then I have to insert component to the particular envi tabs , if DEVB is the component I have to insert the component there. How can I do this I have done some code its inserting the data at the bottom og the XML .
How To Get Two Classes To Get Objects From Each Other
Oct 18, 2014I'm quite new to Java. I have some trouble with understanding how to get two classes to get objects from each other (if that is the correct term).
Lets say I have a login class, in which I have a method checking what the user has entered into the console (I have not displayed the whole code, but this class works as it should and give the user an option to enter username and password and return it true if entered correct).
public static boolean validateUserPass(String userName, String password) {
String[] user = {"admin"};
String[] passwords = {"firkanten"};
boolean check = false;
for (int i = 0; i < user.length; i++) {
if (userName.equals(user[i])) {
if (password.equals(passwords[i])) {
check = true;
Now, in another class I want a display box to appear on the screen and give the user three options: Click yes, no or cancel. I get this to run perfectly alone, this is not the hard part for me. I want the display box only to appear when the correct username and password is given, but I can't seem to figure out how to do this probably.
Getting Names Of Objects?
Jan 22, 2015In my project I had to create 2 classes, Room and Animal.
Room had to have an array (NOT arrayList-I know theyre better and easier but I need to use an array, for now) This array must be able to be populated by 10 "Animals", and the Room class needs two methods, a method to add animal a to the room (rooms array) and a toString() that returns the name of the room and the names of the animals in the room. The teacher added a hint saying that this toString() should reference the animal classes toString()
Here is my code thus far:
public class Room {
private String name;
Animal[] inRoom = new Animal[10];
public Room(String roomName){
name = roomName;
} public void addAnimal(Animal a){
for(int i = 0; i < 10; i++){
[code].....
XML Editing Using DOM Objects?
Sep 29, 2014I have a requirement to insert the data into xml file . I have used DOM class for doing this.
Below is my xml file
<code>
-<deployments>
-<applications>
-<application>
<name> PCMH</name>
-<envs>
-<env>
<name> DEVA</name>
<version>1.0.0 </version>
[code]....
The thing is if SITA is the name then I have to insert component to the particular envi tabs , if DEVB is the component I have to insert the component there. How can I do this I have done some code its inserting the data at the bottom og the XML.
Objects Being Displayed On Top Of One Another?
Dec 15, 2014I am making a game in java and for the game board i want to fill the screen with blocks. to do this i stored objects of a class that displays squares into an array list and displayed the array list. however, when i do this all of the squares are drawn on top of anther at the final squares coordinates and i dont know why.
here is the code
// code for adding the squares into the array
nt x = 0;
int y = 0;
int size = 10;
static ArrayList<Map> map = new ArrayList<Map>();
//static ArrayList<Items> items = new ArrayList<Items>();
[code]....
Can't Create New Die Objects?
Apr 2, 2015I'm having trouble creating two new die objects for the PairofDie class. I'm trying to run two separate die and print the face value and then add both numbers up and print those values as well.
public class Die {
private final int MAX = 6;
private int faceValue;
//private int faceValue2;
public Die(){
faceValue = 1;
[Code] .....
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
The method Die() is undefined for the type PairofDice
The method Die() is undefined for the type PairofDice
at PairofDice.main(PairofDice.java:6)
Iterate Through Objects
Feb 27, 2015I would like to know how I can iterate through objects . I have a manually created linked list (without using the built-in method one). So in the memory my object looks like this(attachment).I would like to do a for loop or while loop to get each element under the test3.head.
View Replies View RelatedArray Of Objects
Mar 28, 2014Exercise the Coin class using a driver class in which 5 coins are flipped, as a group, 1024 times. Display the number of times exactly 4 tails are obtained. Display the number of times exactly 5 tails are obtained. Use an array of Coin.
how to put an object into an array?I know how to make a coin class with a Heads and Tails, but I dont know how to make 5 coins all at once.
How To Compare Objects With Another
Feb 3, 2014I have the following method stubs to complete:
public class Item{
private int myId;
private int myInv;
public Item(int id, int inv){
myId = id;
myInv = inv;
[Code] .....
I do not understand how to complete the compareTo() method and the equals() method. I understand that the compareTo() to should return 1 if the argument is smaller -1 if its bigger and 0 if they are the same, but I do not understand how it's possible to compare the current object with the object passed in as the parameter.
This is what I tried for the compareTo():
public int compareTo(Item other){
return this.compareTo(other);
}
But my compiler tells me its a recursive call so I am not sure if I am doing this correctly.
Basically I am supposed to compare an object to another but I am not sure how to access the object that is not passed in as a parameter and compare it. Same goes for the equals(). This is what I tried for that (compiler also says its a recursive call):
public boolean equals(Item other){
return this.equals(other);
}
How Many Objects Are Created
Jan 19, 2014String s= new String ("Hello");
String a = new String ("Hello");
As per my understanding the first line creates 2 objects : 1 for the heap memory and 1 for String pool
2nd line : new object created and no new object created in the String pool as the keyword already exists in the pool.
So the total number of objects created after the execution of 2 lines are : 3
Unwanted Changes In Objects
Nov 22, 2014I can't come up with a simple scenario so I'll use my actual code to explain the problem, and it's going to be related to java.awt.Color, but my problem is general, not awt dependent. Although I will shorten my code to show only what I think is relevant to the problem.
Java Code:
public class GameColor {
public abstract class Effect {
public int strength;
public Effect(int strength) {
this.strength = strength;
}
public abstract Color get(Color color);
[Code] ....
I have my reasons for having a SetHue inner class and a setHue method that practically do the same thing. The inner abstract class Effect and inner class SetHue was static but I changed it when I testing what could cause this problem, later I will need them to be static, but since they don't affect the problem I don't think it matters if they're static or not.
So down to the problem, I create three new GameColor instances which all are 255, 0, 0, basically red. Then I do setHue(0) method on the first one, setHue(20) on the second one, and setHue(40) on the last one. And for some reason all of them have a hue of 40, whereas the last one should've had this, so basically the last time I call setHue on the instances of GameColor, changes the hue of all of these colours to that hue. I want it to be individually affected, but all of them are affected. This is where I apply these changes:
Java Code:
colo1.setHue(0);
colo2.setHue(20);
colo3.setHue(40); mh_sh_highlight_all('java');
And how I initialise the colors:
Java Code:
public GameColor colo1 = GameColor.RED;
public GameColor colo2 = GameColor.RED;
public GameColor colo3 = GameColor.RED; mh_sh_highlight_all('java');
Using Objects In HashMaps
Mar 21, 2014I am currently trying to implement a hashmap from a class i currently have that is called 'Paper'
My paper class consists of:
String Title;
String[] author;
What I am wondering, is if there is anyway I can call these seperate attributes to be both the key and the value of the hashmap. Currently I cannot see a way to call individual values, only the class itself.
Compare All Objects In ArrayList To All Others But Not Self
Mar 15, 2015I have a ArrayList of objects of class called HockeyPlayer (ArrayList<HockeyPlayer>). A HockeyPlayer has a String name and int number of goals.
This is my current work for comparing each object in the list to every other and printing them to screen:
Iterator<HockeyPlayer> it = hockeyPlayersList.iterator();
while (it.hasNext()) {
HockeyPlayer singleHockeyPlayer = it.next(); //the first one encountered
// HockeyPlayer nextHockeyPlayer = it.next(); //the next one encountered
[Code]...
This of course produces some duplication in the print-out: These are the equal hockey players: Who Ever wears jersey. This type of employee is paid: true. This employee has post-secondary education: false. This employee's work is to play. This hockey player has scored 0 goals.
Jason Harrison wears jersey. This type of employee is paid: true. This employee has post-secondary education: false. This employee's work is to play. This hockey player has scored 0 goals.
These are the equal hockey players: Jason Harrison wears jersey. This type of employee is paid: true. This employee has post-secondary education: false. This employee's work is to play. This hockey player has scored 0 goals.
Who Ever wears jersey. This type of employee is paid: true. This employee has post-secondary education: false. This employee's work is to play. This hockey player has scored 0 goals.
How do I remove the duplication in the print-out?