How To Create Unmodified / Read Only List
Jun 26, 2014How to create a unmodifiable/read-only list in Java?
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How To Create Unmodifiable / Read Only List In Java
Jun 26, 2014How to create a unmodifiable/read-only list in Java?
View Replies View RelatedHow To Create Unmodifiable / Read-only List In Java
Jun 26, 2014I am a java fresher, How to create a unmodifiable/read-only list in Java?
View Replies View RelatedCannot Read Into Array List
Apr 5, 2014I am creating a hangman game and I want to read in a list of words from a text file, but after the user inputs the name of the text file. I get 'Exception in thread "main" java.lang.NullPointerException'.
Here is the code, where I think the problems lie.
public void runModel(){
ArrayList<String> pirateWordsList = new ArrayList<String>();
System.out.println("What is the name of the file you would like to load? (The file included is called piratewords.txt'");
Scanner in=new Scanner(System.in);
String file=in.next();
load(file);
[Code] ....
The full error message is this:
Exception in thread "main" java.lang.NullPointerException
at uk.ac.aber.dcs.pirate_hangman.Model.load(Model.jav a:108)
at uk.ac.aber.dcs.pirate_hangman.Model.runModel(Model .java:45)
at uk.ac.aber.dcs.pirate_hangman.Main.main(Main.java: 6)
Read String To List (Integer) And Back
Feb 14, 2014I 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.
Searching Array - Read From A File That Is List Of Songs
Oct 10, 2014I have an assignment for my intro class that requires me to read from a file that is a list of songs, their artists, and the year they were released. As seen below, a print line statement prompts the user to enter an artist name, and then it uses a buffered reader to gain input, and then it is supposed to match that input.I realize that this is not a complete statement, but I'm mostly concerned with getting the .indexOf statement to work.Currently it only returns the first object in the array.
for(int i = 0; i < song.length; i++) {
System.out.println("Enter an Artist name");
String input1 = kb.readLine();
if (song[i].getArtist().indexOf(input1) > -1) {
/*tried changing -1 to -2. When I do, it returns the
first array entry, regardless of what I input*/
System.out.println(song[i].toString());
}
}
Use Data Read From File To Create Instances?
Sep 10, 2014"Write a program (save the program as ProductInventory.java) that will read data about 5 products from a text file (Products.txt. The program should use the data read from the file to create instances (objects) of Product.java(Use Product class as a Reference Type)."
I'm yet to discover how I will get the info from the textfile using scanners but I don't know how to "create instances of a reference type".
This is the code of Product.java that came with the exercise.
public class Product {
private String productCode = "";
private String productName = "";
private int quantity;
private String supplierName = "";
private String supplierAddress = "";
private double price;
[Code] .....
By the way, the exercise also required me to use the abstract class ProductLister. To be clearer, the text file is kinda like this:
54643
Rizer Mouse
Mark5s Merchandising
Marquee Mall
4
205.50
23412
Acer Ultrabook
JohnJade Merchandise
Cornal City
2
62200.00
93112
Dell Ultrabook
Octagon Marketing
Cornal City
3
68900.00
22126
Macbook Air Pro
Computerware Services
San Beda, Chad
2
93500.00
EJB / EE :: Create Json From List Data
Dec 16, 2014Create Json from a List's data
View Replies View RelatedHow To Create Withdraw / Deposit Feature So It Cannot Exceed Maximum Limit (read)
Nov 25, 2014So lets say I got maximum of 20 deposit, I want to create a method/function (idk what proper name for it is) so that you cannot deposit more than 20 nor withdraw more than you have in your account, so this function checks your account, if your total is for example 18 and you're trying to deposit 10, it rejects it and doesn't add to your total and pops up with a message, vice versa for withdraw.
This is what I have so far . Not I already have the maximum limit + total feature created just not displayed here
Java Code:
public void depositMoney (int dMoney) {
if(DMoney > 0 ) {
totalMoney = totalMoney + dMoney;
} else {
System.out.println("Please insert money more than 0");
[Code] ....
Create A Java Program That Can Read Specific Data Within Csv File To Work Out Averages
Aug 7, 2014i am fairly new to java but have made a few projects so i do know most aspects that would allow me to complete the task its just i have been stuck at the same place now for 2 days.The project is to create a java program that can read specific data within a csv file to work out the averages etc. The csv file is a database of different weather stats . an example of the first 12 months of the csv file is below..
[CSV FILE]
year ,month,average rainfall etc
1946 15.70.616108.131.5
1946 28.23.56111.871
1946 38.82932.9 102.9
1946 414.16.3029.2 150.5
1946 513.96060.7 143.6
[code]...
I know that once the data is indexed i can than use a double to find the average of the 12 specific pieces of data and so on. once this is complete i should than be able to transfer the data to a simple graph.
Swing/AWT/SWT :: Create A Sub Menu For Every List Item In A Jlist
Oct 8, 2014I would like to create a sub menu for every list item in a Jlist. I need the UI like avast interface. If we hover over an list item, its sub menu should be shown. I attempted to put an sub menu but didn't work. Is this possible in Swing?
View Replies View RelatedJSP :: Random List Of Links - Create Web Pages Dynamically
May 1, 2014I have a random list of links whose title I am getting from the database. I'd like to catch one of these links when the user clicks one of them and process it from a single jsp file. Possible?
<ul>
<%
Random random=new Random();
TreeSet<Integer> ts=new TreeSet<Integer>();
for(int i=0;i<8;i++) {
randomInteger=al.get(random.nextInt(al.size()));
ts.add(randomInteger);
[Code] ....
E.g.: when user clicks one of these links, can I dynamically call a web page that fetches information from the click and gets values from a database and insert it on JSP page....
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 RelatedJavaFX 2.0 :: Create List Of Entities - Multi-row Tableview?
Apr 10, 2015I would like to create list of entities which is populated by a search function with the data coming from our REST webservice. However I would like it to be multi-line, with the first line being details from the entity itself and the second line buttons for options that can be performed.
So as an example say my entity is People, the first line would contain columns for first name, last name, gender, DOB, etc. The second line would be buttons for "Edit Person", "Print Person details". With the standard TableView I can't see anyway to alternate between one row of data and another row of buttons.
Create Program Which Inherit Stack And Queue From A Linked List Class
Nov 18, 2014I want to create java program in which i want to inherit stack and queue from a linked list class and also make infix to postfix inherit from stack and periority queue from queue class.Ho can i make this program.
View Replies View RelatedJSF :: Create A List Or Array Of Child Elements To Feed To Java Bean
Feb 5, 2014I have a project I am currently working on using Primefaces and MySQL. I have a page that will display information queried from the database. I have textfields that will display the data from a given record. But I want to ensure that the displayed data cannot be altered. I decided on disabling the textfields unless the create or edit button were clicked. At which point all textfields will be enabled for editing, and cleared if create button was clicked. I want to push the disabling/enabling of the elements back to a managed bean, but I want to have the bean take in two lists or arrays, one containing all elements by ID and one containing a list of exempt elements. Is there a way I can create a List or Array of the ID's that I can send to the bean? I know little in Javascript and previous attempts to implement it have met with little success.
A short example of the code:
<p:tabView>
<p:tab id=pmDBTab title="PM Database Tab">
<p:panelGrid id="projectInfo">
<p:row id="rowOne">
<p:column id="r1c1" colspan="2">
<p:outputLabel id="searchLabel" for="searchField" value="Search: " style="font-weight: bolder"/>
[Code] ....
I want to create a list that would contain all and another that would contain the exemptions such as searchField, searchCriteria, searchButton, projectList and viewButton. The actual exemption list is far smaller than the list of all children. I have found sources that can disable the elements with a java bean, but I have not been able to find one that would allow me to define those that should and should not be disabled, then vice versa for enabling.
Read Input File And Create Output With Anagram For Words In File
Sep 24, 2014Well my code is supposed to ask for an input file and then (ex: input.txt), read the input file and create an output.txt file with the anagram for the words in the file. Also it should be displayed on the screen. However my code doesn't display the anagram on screen or the output file!
Heres is the code:
import java.io.*;
import java.lang.*;
import java.util.*;
/* This program will read a file given by the user, read the words within the file and determine anagrams of the given words. If the file that the user inputs is empty, then the program will output "The input file is empty."
* The program will read the file line by line, counting the total number of words read. If there are more than 50 words, "There are more than 50 words."
* will be printed, and the program will terminate. After each line is read, the words in the line will be separated,punctuation characters will be removed, and upper case characters will be switched to lower case.
* If any word is larger than 12 characters, that word will not be considered in the total amount of words in the file and it will not be sorted.
* After each word is read, the letters will be sorted and stored into an array containing each
* word's 'signature'. After all the words have been read, words will be printed to the output file on the same line based upon their signature.
*/
public class Anagram {
//Creating constants for maximum words in file and maximum chars in word
public static final int MAX_CHARS = 12;
public static final int MAX_WORDS = 50;
[Code] ....
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.
How To Append New Entry In A List Of 100,000 Names Without Iterating List Each Time
Apr 22, 2015I have a list of 100,000 + names and I need to append to that list another 100,000 names. Each name must be unique. Currently I iterate through the entire list to be sure the name does not exist. As you can imagine this is very slow. I am new to Java and I am maintaining a 15+ year old product. Is there a better way to check for an existing name?
View Replies View RelatedUnable To Filter A List And Then Assign Results To New List
Dec 30, 2014I receive a java.lang.NumberFormatException: For input string: ""DepDelayMinutes"" error when trying to filter a list and then assign the results to a new list.
I have edited the code so it is an int that throws the exception so it isn't the presence of a string that is causing the error - java.lang.NumberFormatException: For input string: ""0914"" .
I believe the issue is because of the two sets of double quotes but I do not understand how they came about. The original dataset does not have any quotes whatsoever.
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.function.Predicate;
import java.util.stream.Collectors;
public class FilterObjects extends Thread{
[Code]...
Iterating Over List And Inserting Each Element From List Into BST?
Jul 5, 2014Suppose i have given a List<Intervals> list; I am iterating over list and inserting each element from list into BST, if time require to insert into BST is logn then what is the total time require to insert all the elements into tree ?
logn or nlogn ?
Linked List Implementation Of List Interface?
Oct 5, 2013So we have an assignment regarding a linked list implementation of a given list interface.
In my list interface, the method contains(T anEntry) is defined.
In the LList implementation, contains is already implemented as part of getting the core methods in.
Now I am being tasked with the following:
Provide a second implementation of the method contains2(T anEntry) that calls a private recursive method
Private boolean contains (T anEntry, Node startNode) that returns whether the list that starts at startNode contains the entry anEntry.
I've written the private recursive method already. That's not an issue (at least not right now).
But what I don't understand is how startNode is supposed to be populated when this private contains method is called from the public contains2 method? contains2 only takes one parameter: anEntry. the private method takes two parameters: anEntry and startNode. How am i supposed to provide startNode when I am calling contains2?
Add To List With ID Makes List Upside Down
Feb 14, 2015I saved the content of an ArrayList<SomeClass> to a file
I write each serialised object to the file by adding to each an id that is created with list.indexOf(object) (and saved before each object)
So I can repopulated the list with SomeClass objects in the same order as they were and once I reload the file, I do list.add(id,object)...
Well my list is populated upside down, I mean the first object is the last and the other way around, If i remove the id when I do the add(object)...
Create A Class That Will Accept Dates In Various Formats And Create A Range
Feb 1, 2014In the class below I'm trying to create a class that will accept dates in various formats and create a range. The first constructor is easy because I send it the begin date and end date as Date objects. Now I want to send a month(and year) in a constructor and derive the begin and end dates from it. In my constructor that accepts the month/year I need to put the this(startDate, endDate) at the top to be allowed, but the parameters are not built yet.
package com.scg.athrowaway;
import java.util.Calendar;
import java.util.Date;
public class DateRange {
private Date startDate;
private Date endDate;
[code].....
List Interface Class That Has Operations For Linked List And LList Class
Oct 6, 2014I have this ListInterface class that has operations for my linked list and a LList class. The Llist and ListInterface classes are perfect. My job is to create a driver, or a demo class that showcases these operations. That being said, heres the driver so far:
import java.util.*;
public abstract class DriverWilson implements ListInterface
{
public static void main(String[] args)
{
LList a = new LList();
[code]....
Create A Menu Where The User Can Create A New Account?
Oct 5, 2014I'm having some difficulty with my bank account project. I'm supposed to create a menu where the user can create a new account, withdraw, deposit, view their balance, and exit. There's issues with the account creation.
Here's my necessitated class below: BankAccount, TestBankAccount, SavingsAccount, CurrentAccount, and Bank
/*---------------------------------------------------
Plagiarism Statement
I certify that this assignment is my own work and that I have not copied in part or whole or otherwise plagiarized the work of other students and/or persons.
----------------------------------------------------------*/
package BankAccount;
import java.util.Date;
import java.util.Random;
//Project 3
public class BankAccount {
protected static int accountID;
[code]....