Iterate Over List And Get Values From Object?
Jan 22, 2015first i looked at this example and understand this fine:
import java.util.ArrayList;
import java.util.Iterator;
public class Main {
[Code]....
ADVERTISEMENT
Learning To Iterate A List And Search Through Another
May 5, 2015I am learning iterating through lists. What I have so far is two Hash Sets and two Tree sets. Hash Set 1 and Tree set 1 include the words from Roughing it by Mark Twain. Hash set 2 and tree set 2 include the words from Adventures of Huckleberry Finn by Mark Twain. (Everything is read from a file I made).
I am stuck trying to find out how to "Iterate through the words in HashSet1 and search for these words in both TreeSet2 and in HashSet2".Here is my code:
public class UsingSets {
public static void main(String[] args) throws FileNotFoundException {
String riHashIterator = null;
HashSet<String> riHash = new HashSet<>();
Scanner input = new Scanner(new File("roughingit.txt"));
while(input.hasNext()){
String riHashWords = input.next();
riHashWords = riHashWords.toLowerCase();
riHash.add(riHashWords);
[code]....
Array - How To Iterate Through Only Values Greater Than 0
Feb 9, 2014I have an 46x9 array. I only have 108 values in the array for which I need to perform preliminary computations. How do I get the read to only read the 108 values whose values are greater than 0 and skip the other 495 whose values are 0?
View Replies View RelatedIterate Linked List And Map With Properties File Value
Jan 22, 2014I have `country.properties` file which have values as follows:
1=USA
91=India
20=Egypt
358=Finland
33=France
679=Fiji
and, have a response class file, which is setting a response from database to display it on `JSP` file. The value that I am getting from database is in the form of `code` or `integer`. I needed to have that value from the database and before setting the response I need to use `getProperty(code)` and save the String representation of that code into a new list and then pass that list to `setResponse`. For e.g: This is the value I am getting from database:
col1 | col2 | col3 |
1 helo done
I needed to show on my JSP page as:
col1 | col2 | col3 |
USA helo done
I was following this tutorial [URL].... but not able to exactly understand how to achieve the same.
This is my `DAOImpl` where I needed to `iterate` and save the `mapped key-value` in a new list and then pass to `JSP` page
public class CountDAOImpl implements IDataDAO {
private Connection conn = null;
private Statement statement = null;
private ResultSet rs = null;
private List<String> country_code = new LinkedList<String>();
[Code] ....
JSP :: Iterate And Populate Values Of TXT File Into Text Area
May 15, 2014How can I read a text file present in my local directory say (C://test.txt) , iterate and populate the values of test.txt into a text area of the JSP page?
Contents in the test.txt file:
username:test
password:test123
domain:test321
DBname:testDB
Sort Linked List Through The Nodes Of List - Data Of Calling Object
Feb 14, 2014I have some class called sorted to sort the linked list through the nodes of the list. and other class to test this ability, i made object of the sort class called "list1" and insert the values to the linked list.
If i make other object called "list2" and want to merge those two lists by using method merge in sort class. And wrote code of
list1.merge(list2);
How can the merge method in sort class know the values of list1 that called it as this object is created in other class.
Get Object Strings To Print In List So That User Can Select That Object To Manipulate Its Attributes
Oct 7, 2014I am new to Java and have read books, the Java docs, and searched the Internet for my problem to no avail. I have an Array of objects that contains strings. How can I get the object's strings to print in a list so that the user can select that object to manipulate its attributes? For example, the user can select "Guitar 1" from a list and manipulate its attributes like tuning it, playing it, etc. I have a class called Instruments and created 10 guitar objects.Here is the code:
Instrument [] guitar = new Instrument[10];
for (int i = 0; i < 10; i++) {
guitar[0] = new Instrument("Guitar 1");
guitar[1] = new Instrument("Guitar 2");
guitar[2] = new Instrument("Guitar 3");
guitar[3] = new Instrument("Guitar 4");
guitar[4] = new Instrument("Guitar 5");
guitar[5] = new Instrument("Guitar 6");
[code]...
Display Properties Of Each Object Instead Of Object Array List Itself?
Mar 23, 2015If I set a Jlist to contain an array of objects, how can I display properties of each object instead of the object array list itself. Ex:
Instead of:
Person1
Person2
Person3
display values such as each person name within the Jlist:
Mike
Paul
Andrew
Searching For Object In Linked List Then Removing The Object
Nov 19, 2014I have just started working with linked lists. I have a linked list of Objects and I want to be able to search for a specific object. But currently my code continues to return false. Also how would I go about removing the first index of the linked list.
public static void main(String[] args) {
LinkedList<Cookies> ml = new LinkedList<>();
int choice = 0;
while (choice >= 0) {
choice = menu();
[Code] ....
Accessing Map Values Through A List
Apr 15, 2013I am trying to create a method in BlueJ which needs the values from a Map to be copied into a List so I can use the List methods min() and max(). Here is the method I have created so far:
public String findNamesInPageRange()
{
int minOfRange = Integer.parseInt(OUDialog.request("Input number for start of range"));
int maxOfRange = Integer.parseInt(OUDialog.request("Input number for end of range"));
String foundIt = null;
for(String eachKey : bookIndex.keySet()) {
List<Integer> pageList = new ArrayList<>(); //Cannot access values from a map using this List
if((minOfRange >= Collections.min(pageList)) && (maxOfRange <= Collections.max(pageList))) {
foundIt = eachKey;
}
}
return foundIt;
}
As can be seen there is a comment showing where my problem lies.
The Map is coded as Map<String, Set<Integer>> bookIndex = new TreeMap<>();
Ive tried using bookIndex.values() as the argument of the List but I get an incompatible type error
So, how can this problem I am having be resolved?
Printing Random Values From Array List
Jun 15, 2014I am having a hard time trying to figure out how to print random numbers from a an array list. I tried google but nothing worked. I have to pick certain values from two lists and print them on the screen. I have included comments in the code to facilitate the explanation.
import java.util.Random;
public class Parachute {
public static void main(String[] args) {
Random randomNumbers=new Random();
int number;
int array []={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21};
char A[] = {'a', 'b', 'c','d','e','f','g','h', 'i','j','k','l','m','n','o','p','q'};
[Code]...
Finding Duplicate Values In Array List
Jul 8, 2014I am working on this project that wants me to write a program that inputs 20 numbers, each of which is between 10 and 100, inclusive. As each number is read, display it only if it is not a duplicate of a number already read. The only part I am confused about is how to go about checking for duplicate values that the user may enter. And IF the user does input a duplicate value, it should not be stored again.In addition, the value entered should be printed out after it is entered along side the value that have been previously entered by the user such as:
23
23 45
23 45 67
23 45 67 12
and so on.
I am still fairly new at java programming.
import java.util.*;
public class NumberArray
{
public static void main(String[] args) {
// declare an array with 5 elements
[code]....
Code That Find Median Value In List Of Values
Mar 19, 2014a simple Java program for finding the median value in a list of values with the following requirements:
- Create an array with an even number of values in it (an odd number of values is little bit trickier, so if you want a challenge, do it for either an even or odd number of values)
- Find the value with an equal number of values greater than the value as there are values less than the value
- Your solution must not require a sorted list of values - Output the median value
This assignment is intended to get you to demonstrate basic knowledge of arrays, and to create methods with both input and output.
JSP :: Populate A Dropdown With Fixed / Static List Of Values?
Nov 3, 2014I have a fixed list of 20+ values to be populated in a dropdown. The set of values are always going to remain the same, no future scope of modifications, additions or deletions.
Listing each of them as <option> in JSP is making the page look cluttered. Or is it better reading it as a comma-separated string from a properties file and then iterating to populate the dropdown.
What will be the best approach to populate such a dropdown in JSP?
Retrieving Values Of Object
Aug 8, 2014How do I retrieve values of an object?
public Software[] getSoftware(int index){
return software;}
The object is initialized and i get no errors when entering values .. but when i try to print by calling getSoftware I get :
[Ldd1318398project4.Software;@257f6796
How To Assign Values To Object
Apr 25, 2015simple assignment of values to a previously initialized object?
See the method useModel ()
The idea is, assign the values to the temporary object, data
Then plunk it into this statement:
model.addRow ( data );
Simple enough?
I've been putzing with the syntax for multiple hours, over days, now.
With and without
[0];,
Netbeans keeps giving me: Illegal start of expression data is declared as an array of Object, although, in this case, it does not need to be an array. What is the correct syntax?
Java Code: //--
import java.awt.BorderLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Date;
import javax.swing.JFrame;
[Code]....
Array List That Contain String Object
May 5, 2014Suppose that you have an ArrayList and that it contains String objects. Which declaration of the ArrayList requires that objects retrieved using the get method be cast to Strings before calling a String method?
I. ArrayList a = new ArrayList();
II. ArrayList<Object> a = new ArrayList<Object>;
III. ArrayList<String> a = new ArrayList<String>;
A. I only
B. II only
C. III only
D. I and II only
E. I, II, and III
I know that all of these are ways to declare an Array List, but I am unfamiliar with the last two since I usually just declare my Array Lists with the first option.
One Object / One Instance Variable - Different Values?
Feb 5, 2015Let's pretend I'm working on an RPG. Like in all RPGs, there are items found all throughout the imaginary world. Each player and NPC can obtain an item. My question will concern those items.
In other words, I'd like to use instances of a class in multiple places of the code. Each instance will have its own, individual values of instance variables, with one obvious exception: itemQuantity should have a different value in playerInventory, npcInventory, etc. Also, I'd like a list of all items that can be found in the game. This list doesn't need itemQuantity at all.
class Items {
String itemName;
float itemWeight;
int itemQuantity;
[Code] ....
The question is: should I really make itemQuantity an instance variable of the Item class? It seems as though for each copy of the Item class I should create a separate copy with different value of itemQuantity, but that's not very efficient. Where is the error in my logic?
What's important is that there may be plenty items in a game and a player may be given power to create new items during the course of the game.
JTextField - Enter Some Values For Object
Mar 29, 2014I'm working with a project there ill need to enter some values for an Object and for this i'm using JTextField. However some of the variables are of the types double, int and bool. Is there a different method of reading thees types?
for example:
double playTime = this.playTime.getText();
This won't work because playTime is of type double and .getText(); takes a String.
How will i handle this? Id rather not convert from String to Double if its possible.
How To Modify Property Of Object Stored In List
Jul 31, 2014I'm facing a problem in below scenario:
List lst = tDAO.executeReport();
lst contains list of objects and one of the objects contains the property bDate(Timestamp) which has the value 28-2-1989 00:00:00.0, now I just wants to change the value into 28-2-1989 and store it back into the List as a Timestamp. how can I do that.
Deleting Complex Object In Java List
Sep 3, 2014I am following those three tutorials and I have completed it with success.
( [URL] .... )
( [URL] .... )
( [URL] .... )
But then, as author haven't implemented removeCountries method I tried to create it. What I did initially was to just add to class Countries this method:
public boolean removeCountry(Country country) {
return countries.remove(country);
}
But although compiler wasn't complaining it didn't work. Actually it worked last night (before reboot) but not today. Must be some SOAP iterator/binding thing or whatever. Or I thought that it worked but in fact it didn't.
Here are original classes:
//-------------------------------
public class Country {
String CountryId;
String CountryName;
public Country() {
super();
[Code] ....
I would like to avoid my own iterator as JDeveloper can generate automatically iterators for webservices, but if I can't get it that way, what would be better way to write above mentioned iterator in removeCountry method?
Is there any way to remove object directly with something like this:
co.countries.remove(o);
co.removeCountry(country)
using method
// This left unused
public boolean removeCountry(Country country) {
return countries.remove(country);
}
from class Countries?
Parameters should be set by web service iterator.
Passing Object As Parameter - Combination Values Are All Zero
Mar 8, 2015I have an object that has an instance of another object class as its parameter :
CombinationLock oneHundred = new CombinationLock(28,17,39);
Locker Mickey = new Locker(100, "Mickey", 3, oneHundred);
This is for a locker, which has a combination assigned to the student. Within the locker class I have the following constructor:
public Locker(int locker, String student, int numberOfBooks, CombinationLock combo) {
this.locker = locker;
this.combo = combo;
this.student = student;
this.numberOfBooks = numberOfBooks;
}
combo is the private CombinationLocker object I created within the Locker class. Do I need to pass the combo object on to the CombinationLock class? For reason, I do not comprehend, the combination password from the main class is not passing through to the CombinationLock class, and the combination values are all zero.
Initializing Object Outputs Zeroes Instead Of Values Given To It
Oct 30, 2014public class Check2
{
private int red;
private int green;
private int blue;
public Check2(){
red = 0;
green = 0;
blue = 0;
[Code] .....
And when i uses it in another class named "Check" it returns zeroes :
public class Check
{
public static void main(String[] args) {
Check2 obj = new Check2(125,254,12); // the toString method should return the values i gave it here . but it shows me zeroes instead.
System.out.println("the colors are " + obj.toString());
}
}
Output : the colors are (0,0,0)
Create Object Of List Type Such As Text File?
Dec 27, 2014I want to create a program where I need to create an object of list type such as text file will contain nos like 1,2,3,4,5 and write into text file and delete the in FIFO order i.e 1,2,3,4,5...how i can achieve to write a program? I tried bt everytime got concurrent modification exception or Array out of bound exception.
View Replies View RelatedInvoking Subclass Method On Object In A Linked List
Apr 9, 2014I am trying to put a reference to a given subclass object into a linked list, and then come back later, and invoke a method of the subclass object that is in a given spot in the linked list. This produces an error because Object does not have that method. Is it necessary to cast the object to the correct subclass every time I want to use one of its methods, or is there a way to convince the JVM to treat it as always of type MySubclass?
View Replies View RelatedJSF :: Passing Parameters From Normal List Object Without Using DataModel
Oct 9, 2014How to use the id parameter in my documents entity to download documents from a list of documents. Normally I use ListDataModel and the getRowData method. I would like to know how to achieve the same thing using an ordinary List object.
My list of documents is called List<CountryDocs> selectedDocs;
<h:form>
<p:dataTable value="#{countryDocBean.selectedDocs}" var="docs">
<p:commandLink id="download" value="Download" ajax="false">
<p:fileDownload value="#{countryDocBean.downloadedFile}"
contentDisposition="attachment"/>
[Code] ....
Clicking on the download link calls the following method in my managed bean:
@ManagedBean(name = "countryDocBean")
@SessionScoped
public class CountryDocBean {
private List<CountryDocs> selectedDocs;
public StreamedContent getDownloadedFile() {
[Code] ....
Debugging shows the value for the id is 0 and this results in a NullPointerException. I've tried several methods for grabbing the document id in my backing bean, but no luck yet. I also read about the the ViewParams and ViewAction method but they caused validation errors to do with the <f:metadata> tags. I don't know how to obtain this value using a normal List object.