Call Variables From Main To Write To External File
Apr 27, 2015
I have this program, I am wondering if it is possible to call files from the main method and sort them into my saveOneRocord method? If so, how would that look?
my orderProcess Class
package stu.paston.finalprogram;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Scanner;
import java.io.File;
import java.io.PrintWriter;
import java.io.FileWriter;
[Code] .....
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Jun 19, 2014
Whenever I try to write a file to the disk and then load it within the same Class (if it is even possible) ...
It gives me an error: Could not find the main class: score.Score. Program will exit.
I have tried this with 2 different classes and it works fine? Why that error is appearing.
Code:
package score;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.Scanner;
public class Score {
public static void main(String [] args) throws Exception
[Code] .....
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Apr 17, 2014
How do I call a class within the main. For example, this is what i have in my code right now. I am trying to call the class BlackJackGame.
package blackjack;
public class BlackJack {
public BlackJack() {
BlackJackGame();
}
}
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Jul 3, 2014
I am trying to call a constructor from PrepaidCard class in my main method, but I am not sure how to proceed.
As seen below, both the PrepaidCard constructor and the setCardID method have the ability to set the card ID.
public class PrepaidCard
{
public PrepaidCard(String id, int token) {
cardID = id;
tokenBalance = token;
}
public void setCardID(String id, int token) {
cardID = id;
tokenBalance = token;
}
}
Now in this block of code, I can successfully pass the id and token value by calling the setCardID method from the PrepaidCard class. Now I would like to call the PrepaidCard constructor from the PrepaidCard class to pass the id and token value, instead of using the setCardID method.
public class PrepaidCardTest
{
public static void main(String[] args) {
PrepaidCard card2 = new PrepaidCard(id, token);
System.out.print("Enter Card2 cardID: ");
id = input.nextLine();
card2.setCardID(id, token);
}
}
How to call the PrepaidCard constructor from the PrepaidCard class, to successfully pass the id and token value, in my main method?Specifically how to modify or replace this line of code so that it can correctly call the PrepaidCard constructor?
card2.setCardID(id, token);
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Jun 2, 2014
If I had this code:
<h:dataTable value="#{customer.customerList}" var="c"
styleClass="order-table"
headerClass="order-table-header"
rowClasses="order-table-odd-row,order-table-even-row"
>
And in the server getCustomerList() accessed to database, how many times getCustomerList() would be called from I request the xhtml page?. I have read this would be called several times because of JSF internals and It would be better to store it in a variable and access this variable.
1. Is this true this would be called several times? why?
2. If the previous statement was true, how to avoid it, I mean not call the method from a service?
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May 7, 2015
I can call a child method from a main method. If I have a parent called "Assessment", a child called "Quiz", and another child called "test". Can I instinate an object like Assessment a = new test(); and call a method in test.I know the method can be called if I instinate the test t = new test() but that defeats the purpose of inheritance which I'm learning in class.
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Jul 3, 2014
I am trying to call a constructor from PrepaidCard class in my main method, but I am not sure how to proceed.
As seen below, both the PrepaidCard constructor and the setCardID method have the ability to set the card ID.
Java Code:
public class PrepaidCard {
public PrepaidCard(String id, int token) {
cardID = id;
tokenBalance = token;
} public void setCardID(String id, int token) {
cardID = id;
tokenBalance = token;
}
} mh_sh_highlight_all('java');
Now in this block of code, I can successfully pass the id and token value by calling the setCardID method from the PrepaidCard class.
Now I would like to call the PrepaidCard constructor from the PrepaidCard class to pass the id and token value, instead of using the setCardID method.
Java Code:
public class PrepaidCardTest {
public static void main(String[] args) {
PrepaidCard card2 = new PrepaidCard(id, token);
System.out.print("Enter Card2 cardID: ");
id = input.nextLine();
card2.setCardID(id, token);
}
} mh_sh_highlight_all('java');
How to call the PrepaidCard constructor from the PrepaidCard class, to successfully pass the id and token value, in my main method?
Specifically how to modify or replace this line of code so that it can correctly call the PrepaidCard constructor?
Java Code: card2.setCardID(id, token); mh_sh_highlight_all('java');
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Nov 27, 2014
So I have been given this code, below:
public class Person{
/*Complete*/
public String format(){
return String.format( "Name: %s", name );
[Code] ....
And I have been asked to add a new field called name, and call the display method in the main. I need to use an appropriate type and privacy for the name field, and once the code is finished, I should see 'Harry Potter' appear on the command line. However I don't know what it means by field. I've tried googling it and one search result said it is a field parameter, and another search result said it was something completely different, and I don't know which one it is. I've created a parameter 'Private String name;' but it only prints out 'name: null'
This is the code I wrote but it obviously doesn't work?
package Practical8;
public class Person{
Private String name;
public String format(){
return String.format( "Name: %s", name );
[Code] ....
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Dec 9, 2014
The following code is located in my main class called InjectionFix. I have another class where I need to call or initiate the string in the code below. How can I achieve this. I tried to create an Object of the class but I cant do this because my other class doesnt contain a main method.How can I get the other class to initiate the code below which is loacted in my main class.
public static String escapeDN(String name) {
StringBuilder sb = new StringBuilder();
// space or # character at the beginning of a string
if ((name.length() > 0) &&
((name.charAt(0) == ' ') ||
(name.charAt(0) == '#'))) {
[Code] .....
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Mar 25, 2015
I am trying to make a 2d graphical animation using the java swing classes in order to make a frame. I had a basic version working when all of the code was under the main method, but when I moved some into another method it broke it. With y understanding of java my code should work as I create a variable of the method containing the code and then assign the size and exit button. However this causes many problems such as my BeaconFrame method informing me that it is unused when I have used it. Here is my code:
import javax.swing.*;
import java.awt.*;
public class BelishaBeacon {
public void BeaconFrame() {
JFrame frame = new JFrame();
JPanel panel1 = new JPanel();
[code]....
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Aug 27, 2014
For the below program what are the default values passed by the JVM in order to call main() method
class program
{
public static void main(String[] args)
{
System.out.println(args[0]);
System.out.println(args[1]);
}
}
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Dec 19, 2014
For reference I am programming Java in BlueJ. I am fairly new to the language and I am having trouble with sorting.
I am trying to call / test all of the 5 sorting methods (at the same time) in the main class. To be specific, the sorted list has to technically outputted 5 times.
I figured out how to call / test Quicksort:
Sorting.quickSort(friends, 0, friends.length-1);
But the others are not working correctly. Specifically these:
Sorting.mergeSort(friends, 0, friends.length-1);
Sorting.PbubbleSort(friends, 0, friends.length-1);
Sorting.PinsertionSort(friends, 0, friends.length-1);
Sorting.selectionSort(friends, 0, friends.length-1);
For reference, this is the output when it is not sorted:
Smith, John 610-555-7384
Barnes, Sarah215-555-3827
Riley, Mark 733-555-2969
Getz, Laura 663-555-3984
Smith, Larry464-555-3489
Phelps, Frank322-555-2284
Grant, Marsha243-555-2837
This is the output when it is sorted:
Barnes, Sarah215-555-3827
Getz, Laura 663-555-3984
Grant, Marsha243-555-2837
Phelps, Frank322-555-2284
Riley, Mark 733-555-2969
Smith, John 610-555-7384
Smith, Larry464-555-3489
This is the class Sorting, which I should note is all correct:
public class Sorting{
/**
* Swaps to elements in an array. Used by various sorting algorithms.
*
* @param data the array in which the elements are swapped
* @param index1 the index of the first element to be swapped
* @param index2 the index of the second element to be swapped
*/
private static <T extends Comparable<? super T>> void swap(T[] data,
int index1, int index2){
T temp = data[index1];
data[index1] = data[index2];
[Code]...
This is the Main class in which I am supposed to call the sorting methods, SortPhoneList:
public class SortPhoneList{
/**
* Creates an array of Contact objects, sorts them, then prints
* them.
*/
public static void main (String[] args){
Contact[] friends = new Contact[7];
friends[0] = new Contact ("John", "Smith", "610-555-7384");
friends[1] = new Contact ("Sarah", "Barnes", "215-555-3827");
[Code]...
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Dec 3, 2014
I have understood my programming class up to this point and now I have been given a lab that I can't figure out for the life of me. Here what I have to do: Write a program that will call a method (called f) to calculate the following function" f(x)=(x^2)-16...this is what the output should be:
x f(x)
1 -15
2 -12
3 -7
4 0
5 9
6 20
7 33
8 48
9 65
10 84
I guess it also has to print this output in a table even though my professor never mentioned it. Usually
public class Lab12 {
public static int f(int x)
{
return x*x-16;
[code]....
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Jan 15, 2015
a. Create an application named ArithmeticMethods whose main() method holds two integer variables. Assign values to the variables. In turn, pass each value to methods named displayNumberPlus10(), displayNumberPlus100(), and displayNumberPlus1000(). Create each method to perform the task its name implies.
b. Modify the ArithmeticMethods class to accept the values of the two integers from a user at the keyboard.
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Oct 3, 2014
Write a program OutCircle.java that declares and initializes three floating-point variables (r, x, y): the first variable represents the radius r of a circle centered at (0,0) and the second and third variables are the coordinates (x, y) of a point in the plane.Your program should print true if the point is outside the circle and false otherwise. Hint: A point is outside the circle when its distance to the center is greater than the radius.
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Feb 13, 2014
I am just trying to test this array, for a locker combination program that involves classes...but the array is printing out the whacky numbers for the location. When I try to call the method in the main, it does not work. How do I call a method that exist within a class into the main method?
public class locker {
public static void main(String[] args) {
CombinationLock();
[code]....
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Mar 15, 2014
1. creates a file.
2. ask user to write into that file
3. save the file
4. print content of file.
Is my current exercise, so far i have gotten the code to create a file. What should i use to ask user to write into that file and save?
package assignment7;
import java.io.*;
public class Exercise2
{
public static void main ( String [ ] args ) {
String filePath="newfile.txt";
File newFile = new File ( filePath ) ;
[Code] .....
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Mar 17, 2014
1. creates a file.
2. ask user to write into that file
3. save the file
4. print content of file.
is my current exercise.so far i have gotten the code to create a file, and ask the user to input their age.what should i use to save what the user writes into the file?
Java Code:
package assignment7;
import java.io.*;
import java.util.*;
public class Exercise2
{
public static void main ( String [ ] args ) throws IOException
{
Scanner scan = new Scanner(System.in);
[code]....
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Apr 14, 2014
I have a EAR file which has a java class file and EAR file is deployed in weblogic.I have to call the java class of EAR file from a standalone java code which is present inside a JAR.While making the call to EAR i have to pass a parameter from JAR to one of the methods of class file which is present in EAR.
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Feb 14, 2014
I am a JSP/Servlet newbie currently adding the first servlets to a web site that had been static all along. My local instance worked great but the servlets did not respond on the test instance. Apparently, my hosting service provider requires me to use an invoker servlet mapping.
<servlet-mapping>
<servlet-name>invoker</servlet-name>
<url-pattern>/servlet/*</url-pattern>
</servlet-mapping>
Adding this to local web.xml broke the application but the servlets respond on test instance (when their calls are not preceded by another servlet call). A Servlet fails when it is called immediately after another servlet has been called.
What I saw happening on test is URL for first call is of the form:
xxx.org/<app-name>/servlet/<servlet-name>?Id=1
And URL for the second call became:
xxx.org/<app-name>/servlet/servlet/<servlet-name>?Id=1
The servlets are invoked using "href=servlet/<servlet-name>?Id="
How can I avoid the inclusion of 'servlet' in the URL and reset the URL to the JSP page it navigates to after processing of the servlet?
P.S.: I am also trying to enable the Invoker servlet on local so I can troubleshoot easier. I went through the changes to Tomcat's web.xml and context.xml. However, my local servlets did not respond even after calling them using "href=<servlet-name>?Id=". Is there a way I can check if my invoker is active?
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Dec 23, 2013
I am newbie in java and little bit known to apex. I write an java code and compile it to class file. Now i want to call that class file from an push of button on apex. When button is pushed i need some arguments to be password to java class files . For arguments i need to take the item value from the apex page.
But i stuck on how to call that java class file from apex. On command prompt when i ran java class file, its working.
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Jul 3, 2014
I have an issue with variables/attributes scope inside a jsp tag file.
In short, I have a tag with an attribute named "id". If the page using my tag has a variable called "id" (maybe coming from the spring model) and I call my tag WITHOUT specifying the id attribute, inside my tag I still can acces to the "id" attribute that was defined in the page but I don't want this behavior; if the tag is called without the "id" attribute then it should defaults to empty/null.
Example:
print.tag
<%@ attribute name="id" required="false" type="java.lang.String" %>
id=${id}
site.jsp
(...)
The id is: ${id} // <- Prints 'X'
<my:print /> <- Prints 'X' ! I want it to not print anything in that case
<my:print id="Y"/> <- Prints 'Y'
(...)
What I want is to have the tag attributes live only in the tag, without having any knowledge of any variable outside of the tag itself. Is it possible?
My current workaround is to remove the "id" attribute, enable dynamic attributes and with a scriptlet search in the dynamic attributes map for the "id" and save it in a variable with a different name (e.g. "__id").
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Feb 2, 2014
I want to write an application which stores files inside of itself, like a Zip file, but it will not be a zip or have the zip compression class.
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Dec 8, 2014
I have created a program that allows a pizza shop to enter a customers orders (via 3 seperate panels of options), and calculate a total. Everything works just fine, and now we have to take it a step further and record the sale data in a .txt file (which will include the Crust Type, Toppings, and Extras).
I need to make it so that when a user clicks the calculate button, it also writes to a file (in this case, SalesRecords.txt). I have it all set up, but for some reason I can not get it to work. The error I get is:
"error: unreported exception FileNotFoundException; must be caught or declared to be thrown
PrintWriter outputFile = new PrintWriter(filename);
Here's my code: (the calculate button that I am working with is indicated by a comment)
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.text.DecimalFormat;
import java.io.*;
import java.io.BufferedWriter;
[I looked up the exception I got, and just so everyone knows I made sure that the file "SalesRecords.txt" DOES EXIST. It is in the same folder as my java and class files for this program. I even tried defining the absolute file path for SalesRecords.txt and that changed nothing.
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Mar 5, 2014
i start work with TxT files. And i need know how to write text in the next line if file exist. My code just last text replace new.. Here code :
Main :
package YoYo;
import java.util.Scanner;
public class Main {
static String atsakymas;
static String FileName;
[code]....
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Nov 3, 2014
For a class, I'm making a prison system program. The prison has cell blocks, each cell block has cells, each cell has bed(s), and each bed has prisoners. There are also visitors and visits. I thought, rather than write all of those to different files, I could just write the entire prison to a file and make all the classes under it implement serializable. The instructor said that is a bad practice and we shouldn't do it. So I'm thinking I'll make the prison non-serializable. But the prison has maps of cell blocks, inmates, visitors, and visits. I think I'll make all those serializable and I'll also make everything a cell block contains serializable as well. Then I can just read the cellblocks from the file. But is that too easy as well? Is that a bad practice?
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