I 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.
I have a simple question but I dont understand why I am getting false for this boolean statement.
System.out.println("hash compare " + (trialSearch.returnHash() == fish.returnHash()));
System.out.println("fish.returnHash()" + (fish.returnHash()));
System.out.println("trialSearch.returnHash()" + (trialSearch.returnHash()));
the output is as follow:
hash compare false
fish.returnHash(){T=[1, 2, 3, 5], G=[], A=[0], C=[4]}
trialSearch.returnHash(){T=[1, 2, 3, 5], G=[], A=[0], C=[4]}
why is it printing false for the boolean statment when the two hashmaps contain the same values and keys?
my query is like: "i want to create hashmaps where the inner hashmap contains the key as firstname and value as a Class Student which contains parameters firstname, lastname,etc. I need this hashmap to be accessed by other objects of different classes".
public class Student {
private String FirstName;
private String LastName;
private String EmailAddress;
private String PhoneNumber;
private String Username;
private String Password;
private String EducationalInstitution;
[code]....
As we give the values by Scanner, it should be Stored in Hashmap and how those values can be accessed by other object classes?How does the Logic works? What my next step?
I'm learning Java using BlueJ, I have made a class that has a HashMap of (String, String) that contains an the make of a car and the model.
I want a method to return a collection of all the keys that satisfy a condition, like if someone wants to find what make a certain model is. I know it requires a loop, just not too sure how to write the loop to satisfy the condition.
So I am learning HashMaps/Arraylists and I can't really understand the diamond operator or what it's for. Take the following code for example: Why could we not just do this without the diamond?
Java Code:
import java.util.HashMap;
class Untitled {
public static void main(String[] args) {
HashMap<String, String> map = new HashMap<String, String>();
map.put("California","Sacramento");
map.put("Oregon","Salem");
map.put("Washington","Olympia");
System.out.println(map);
}
} mh_sh_highlight_all('java');
I 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
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 .
I 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 .
I'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.
In 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].....
I 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.
I 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]....
I'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)
I 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 RelatedExercise 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.
I 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);
}
String 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
I 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');
I 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?
Suppose i have a hashMap which includes instances of class Employees and instances of class Customers.
How can i get the employees objects only?
And would it be possible to find the oldest staff by comparing the ages stored in the age fields of the staff objects.
I have GameConsole class with gamePlay(). There are two objects in this class that I want to access from a class in another package.
package blackjackControls;
public class GameConsole {
Player dealer; //both of these objects I am trying to bring over into the blackjackGUI package
Deck playingDeck;
public void gamePlay(){
[code].....
The dealer and playingDeck objects are giving me an error of unresolved. the way it is written I also get a static error on line 37. I know that I have not yet written in the actionEvent statement in the button constructor.
I am trying to access an array of "Movie" objects in my jsp. The array is loaded via
org.springframework.web.servlet.ModelAndView.addObject().
Here is my jsp code:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="security" uri="http://www.springframework.org/security/tags"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
[Code] .....
The System.out.println("jsp page: .... &> results in the output: "jsp page: movielist - [Title: Die Hard; Budget: 20000000, Title: two days in paris; Budget: 1000000]" so I am confident the objects are being loaded into the ModelAndView correctly. However the output of the block is "${movie.name}" instead of the list of movies. My movie object has a getName() method to return a string (and a setName() method). I am not sure why the System.out.println statement can find the movielist attribute, but ${movie.name} is being treated a plain text. There are no execptions thrown or other indications of errors.
I want to clone some Arraylist, but the compiler apparently are just referencing the values to it's original ArrayList. I don't know what should it be:
package projetoteste;
import java.util.ArrayList;
import java.util.List;
public class TestFood {
public static void main(String[] args) {
List food=new ArrayList();
[code]....
Notice that ArrayList dailyMeal should be untouchable, but it return the changes that I made in local for-loop iteration although I didn't added nothing to it, just to it's clone.
Output:
[[[Suco, 1 , 2], [Suco, 1 , 2]], [[Suco, 1 , 2], [Suco, 1 , 2]]]
[[[►, ►, Suco, 1 , 2], [►, ►, Suco, 1 , 2]], [[►, ►, Suco, 1 , 2], [►, ►, Suco, 1 , 2]]]
Given the class MyExample below:
public class MyExample extends GCompound {
//instance variables
public GRect R1 = new GRect(0, 0, 20, 20);
public GRect R2 = new GRect(0, 0, 5, 5); //R2 is in front of R1, but its coordinates are all "inside" of R1's coordinates
//constructor
public MyExample() {
add(R1);
add(R2);
}
}
1) Suppose I'm in a GraphicsProgram and declare:
MyExample myex = new MyExample();
Suppose I have coordinates (x1, y1), and want to find out whether this is the myex object defined in the previous line. I would use:
obj = getElementAt(x, y);
if (obj == myex) (...and so on)
Now suppose I want to test whether the object is the GRect object R1 within myex. Why doesn't the following work?
if(obj ==myex.R1) (...and so on);
Here is the full code that shows my question; it outputs "myex", none of the other outputs come out...
public void run() {
GObject obj1, obj2;
MyExample myex = new MyExample();
add(myex);
obj1 = getElementAt(1, 1);
obj2 = getElementAt(19, 19);
if (obj1 == myex) System.out.println("myex");
if(obj1 == myex.R1) System.out.println("R1");
if(obj1 == myex.R2) System.out.println("R2");
if(obj2 == myex.R1) System.out.println("R11");
if(obj2 == myex.R2) System.out.println("R22");
}
how to refer to objects die1 and die2 in the PairofDie class from the SnakeEyes class and what to do.
public class Die {
private final int MAX = 6;
private int faceValue;
private int sum;
//private int faceValue2;
public Die(){
faceValue = 1;
[code]....
I want to generate a Hash key for a [ Nested Hierarchical nodes]. Any lightweight non-cryptographic hash map functions which generate a key, so that I can use this hashkey to comparison purposes.
NOTE: Security is not a concern for me, I just want to create a Unique ID.