When does an internal cast actually happen? I am aware that compound assignment operator do an internal cast. Does it happen in Assignment 1?Assignment 2?Assignment 3?Assignment 4?
Java Code:
public class Parser{
public static void main( String[] args){
byte b=1;
short s=1;
int i=1;
s=b;//Assignment 1
s<<=b;//Assignment 2
b<<=s;//Assignment 3
s +=i;//Assignment 4
}
} mh_sh_highlight_all('java');
Is it possible to dispose(); an internal frame and keep my main JFrame open.
View Replies View RelatedAny way I can call an internal Frame in java by clicking a button in separate internal Frame to display in a panel in Main JFrame....
View Replies View RelatedI am just learning java now i have a problem where i have to run a test order on my internalOrder class from the orderTester class and i,m not sure how to do this ?
This is the code i have for my order class:
public static void testCase8(){
orders ords = new orders ("Pen", 8, -0.5);
System.out.println("Test Case 8:" + "
" + ords.getOrderDetails());
[Code] ....
This is the code for my Internal class
public final static double DISCOUNT = 0.4;
public InternalOrder(String productName,int quantity ){
super(productName, quantity,DISCOUNT);
}
public void printInternalReport(){
System.out.println("Printing internal report ...");
}
Now my orderTest class is passed though orders class if you need that code i will put it up...
I have a problem where i have to run a test order on my internalOrder class from the orderTester class and I am not sure how to do this. This is the code i have for my orderTester class:
public static void testCase8(){
orders ords = new orders ("Pen", 8, -0.5);
System.out.println("Test Case 8:" + "
" + ords.getOrderDetails());
[Code] ....
this is the code for my Internal class
public InternalOrder(String productName,int quantity ){
super(productName, quantity,DISCOUNT); }
public void printInternalReport(){
System.out.println("Printing internal report ...");
}
Now my orderTest class is passed though orders class and intrenalOrder class if you need that code i will put it up.
My program compiles and runs ok how ever when i open my Jinternal frame and click on one of the JLabels i get a error on the Cmd ther error reads as follows
************************ ERROR **************************
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at JLabelAssignment.mouseClicked(JLabelAssignment.jav a:429)
at java.awt.Component.processMouseEvent(Component.jav a:6508)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3320)
[code]...
I am attempting to make a CoalescedHashMap<K, V> with internal chaining. It isn't a hard concept, but it needs to extend AbstractSet and implement Map<K, V>.
Map requires a remove method that returns a V(value). AbstractSet extends Collection, which requires a remove method that returns a boolean value. It gives a syntax error either way it is done. This is a standard homework assignment for a junior level class, so there must be some way to deal with this. It is annoying as we do not need to implement the remove method, it just throws and exception.
compiling javac is nt recognized as internal or external command
View Replies View RelatedI've installed the Java JDK onto my Windows 8 laptop and the first thing I need to do is run the compiler from the Command Prompt. The first prompt I enter is C:java -version. This worked fine, however when I try to enter the next prompt C:javac -version, I am getting the following screen and messages:
Microsoft Windows [Version 6.3.9600]
(c) 2013 Microsoft Corporation. All rights reserved.
C:UsersMary>java -version
java version "1.8.0_20"
Java(TM) SE Runtime Environment (build 1.8.0_20-b26)
Java HotSpot(TM) 64-Bit Server VM (build 25.20-b23, mixed mode)
C:UsersMary>javac -version
'javac' is not recognized as an internal or external command,
operable program or batch file.
I have entered the path into the environment variables area within my control panel. Not too sure why the first prompt works, but the second doesn't...
I'm deploying Java 8 update 40 to my users and want to know if there's a way to manage sites that prompt the user with warnings about untrusted and unsigned applets?
i'm using the exception.sites file to manage applicable prompts/warnings for our internal sites, but doesn't look like the exception list works for untrusted and unsigned.
is there a way to manage these from an all users level, particularly with a deployment (ie, SCCM)?
I have a design scenario here which is quite interesting and complex. I have a Java class structure as follows,
class A
{
class B;
innerClass B
{
List<class C> listofC;
innerClass C
{
String attribute1;
String attribute2; // Their getter setters
}
}
}
So I have this as an API. Now my challenge is that I need to add one more property to inner class C. i.e attribute3 in innerClass C. I need to do this without disturbing the code in class A by extending these classes or writing a new wrapper, so I can use class C with new properties .
I hope this should be achievable through any design pattern either at runtime or design time.
Im trying to loop through a hashmap of objects. They are defined as People objects. People has two subclasses , Instructor and Student. As I am looping through the map of People, I am searching for class Instructor. If I find it, I want to access its method getDepartment in a println by casting to Instructor. When I do I get a runtime error:
Exception in thread "main" java.lang.ClassCastException: java.util.HashMap$Node cannot be cast to uStaff.Instructor
at uStaff.PersonApp.menu(PersonApp.java:108)
at uStaff.PersonApp.main(PersonApp.java:21)
//Instantiate the different Person, student and instructor objects
Person thisPerson = new Person(01,fName,mName,lName,email,ssn,age);
Student thisStudent = new Student(02,"Stacey","Marie","Morgan","smorgan@gmail.com","213-45-6789",20);
thisStudent.setMajor("music");
Instructor thisInstructor = new Instructor(03,"Joe","Douglass","Wells","joe@drumhaven.com","555-98-3029",46);
thisInstructor.setDepartment("Computer Science");
[code]....
ScriptEngineManager mgr = new ScriptEngineManager();
ScriptEngine engine = mgr.getEngineByName("js");
String expres = calc.getText().toString();
calc.setText(expres);
try {
calc.setText(((double)engine.eval(expres)) + "");
} catch (Exception e) {
}
This line: calc.setText(((double)engine.eval(expres)) + "");
*The error message for this line: Cannot cast from object to Double
I ve got a 2d array and I want to cast it in an 2d arraylist. I ve create a function that cast an array to arraylist. My problem arises, when I tried to parse the whole 2d matrix to the arraylist. I use the following code:
Java Code: double sums[][] = computeSums(lab, projections);
ArrayList<ArrayList<Double>> lists = new ArrayList<ArrayList<Double>>();
ArrayList<Double> nu = new ArrayList<Double>();
System.out.println(sums[0].length);
for (int i = 0; i < sums.length; i++) {
ArrayList<Double> tt = toList(sums[i], nu);
lists.add(tt);
} mh_sh_highlight_all('java');
The problem is that only the first matrix sums[0] is copied to the 2d arraylist sums.length times. How is is possible to store all the different sums matrices to the arraylist??
I'm actually trying to complete the excersise of the Servlets and JSP book in page 303 but I'm getting the following error in Eclipse Cannot cast from String to ArrayList(JSP).Here is the code
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%@ page import="java.util.*" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Hobbies Sharing</title>
</head>
[code]...
The error as it appears in line <% ArrayList al = (ArrayList)request.getParameter("Names"); %>
I have Java code that iterates through files in a directory like this:
for (File child : dir.listFiles()) {
}
Inside that for loop I want to put the filename into a HashMap like this: autocompleteMap.put((String)child,itemList);
The java compiler doesn't like my cast attempt: "Cannot cast from File to String".How do I convert the filename into a String to put into my hash?
JAVA CODE:
package gui.dialog;
import cli.data001;
import java.awt.Color;
import java.awt.Component;
import java.awt.Font;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.Vector;
[Code] ....
OUTPUT:
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Boolean
at javax.swing.plaf.synth.SynthTableUI$SynthBooleanTa bleCellRenderer.getTableCellRendererComponent(Synt hTableUI.java:731)
at javax.swing.JTable.prepareRenderer(JTable.java:573 1)
at javax.swing.plaf.synth.SynthTableUI.paintCell(Synt hTableUI.java:684)
[Code] ....
import java.util.ArrayList;
public class Demo {
class Expr {}
abstract class Factory <T extends Expr> {
abstract T generate();
[Code] ....
Doesn't Factory2 produce Statements?
the output of this:
int x = (int) 24.6;
I'm trying to write a condition to jstl if tag,
<c:forEach var="ledg" items="user_ledgers">
<c:if test="${ledg.transactionID == param['trns']}">
<c:out value="${ledg.name}"/>
</c:if>
</c:forEach>
Ledg is an object of ledger class and transactionID is a field of type long.
I found this error while runtime.
javax.el.PropertyNotFoundException: Property 'transactionID' not found on type java.lang.String
I tried to convert transactioID value to String by several ways. But not working.
String concatenation
<c:if test="${(ledg.transactionID+’’) == param['trns']}">
Using custom tag
<c:set var="equals" scope="page">
<z:doTheyEquals v1="${ledg.transactionID}" v2="${param['trns']}"/>
</c:set>
It also expects String type.
I want to write formatted output on a notepad file using ObjectOutputStream but I am not getting it in human readable formatted form
Here is my person class
public class Person implements Serializable {
private String firstName;
private String lastName;
private int age;
public String getFirstName() {
return firstName;
[code]....
I want to know how to use printStream.print() like method to write formatted output.
I am working on a program where I want the user to input multiple classes.
One int, and one String.
Can this be done? if so, how?
I have a tried to get input from both, like in the code below:
Java Code:
import java.util.Scanner;
public class ForumFlowchart {
public static void main(String[]args){
//Creating scanner.
Scanner input = new Scanner(System.in);
//Get information about job
System.out.println("Type in Int");
int i1 = input.nextInt();
[Code] ....
If I keep my input in the same class, I get the error "Can not cast int to string". My question is, it is possible to get an input from both an Int and a String in the same program?
how is cast a class at a methods parameters? i have a problems in a methods paramter. i draw red line my exception and mymethods is orage color ....
Caffe drink = new Caffe();
CoffeCup cup = new CoffeCup();
cup.setTempeture(100);
drink.drinkcaffe((CaffeCup)(cup.getTempeture()));
[code]....
I have a msg object that contains an ArrayList<Integer> collection. However, in order to send the elements in the array over the udp socket, it needs to be sent as a byte[] array. So why am I using ArrayList<Integer> over byte array in first place? Well when I receive data from socket from embedded c program, I need to get an unsigned representation of the data, and thus I need to store it in integers, since bytes in Java are unsigned and unsigned chars in c that are greater than 127 will yield incorrect values in java. But when I send an ack back over the socket, I need to send the data back as bytes. So I convert the ArrayList<Integer> to a byte array:
Java Code: byte[] data = msg.toByteArray();
DatagramPacket response = new DatagramPacket(data, data.length,
packet.getAddress(), packet.getPort());
public class Gprs {
...
public byte[] toByteArray(){
[Code] ....
The problem is I get an "Cannot cast from Integer to byte" when trying to cast the integer to byte: data[i] = (byte)m_data.get(i);
How can I resolve this?
I'm developing an application to track the status of a production flow-line and have hit a bit of a snag. When attempting to read saved data I run into this:
Exception in thread "main" java.lang.ClassCastException: flowline.End_Of_File cannot be cast to flowline.Operation
at flowline.Station.checkLoadPreviousStationStatus(Station.java:91)
at flowline.Station.main(Station.java:212)
Java Result: 1
I've been reading up on different methods to saving and retrieving data and have decided ObjectInputStream would be the best option.
The save method works fine, I opted to use a EndOfFile class to determine when I've reached the end of the input stream. The problem is, when my loop encounters this object, it doesn't terminate the loop.
public void checkLoadPreviousStationStatus() throws FileNotFoundException, IOException,
ClassNotFoundException, EOFException, TempArrayOutOfBoundsException{
Object loadOpn = null;
End_Of_File eof = new End_Of_File();
File f = new File(fileName);
[Code] .....
The Operation cast is a cast to the objects my LinkedList contains. The highlighted line is where the exception occurs.
I am getting "Type safety: Unchecked cast from Object to LinkedList<EventData>" in eclipse for a piece of code stated below
public LinkedList<EventData> loadFromFile(File file) {
queue=new LinkedList<EventData>();
//Some piece of code
return (LinkedList<EventData>)queue.clone(); //--->getting warning here
}
I know that because clone() method is returning Object, hence compiler doesn't have type information that's why showing warning. I don't want to suppress this warning instead i want to fix it.