Caused by: javax.persistence.NonUniqueResultException: result returns more than one elements
at org.hibernate.ejb.QueryImpl.getSingleResult(QueryI mpl.java:109)
What are the common reasons for the above exception and the suitable fixes?
The error I get when I execute my java file.
Exception in thread "main" java.lang.NullPointerExceptionat DogTestDrive.main(DogTestDrive.java:19)
Here is the source
class Dog {
int size;
String name;
void bark () {
if (size < 60) {
System.out.println("Woof woof");
[code]....
Some background: I'm reading "Head first Java 2nd edition" and I'm going through the examples which is showing me how to change the state of an object. The original code looks like the code below, however the previous chapter went over creating array's of an object, so I created an array of the object "Dog" and wanted to re-write it this way. To my understanding, it should work but it's giving me that error when I execute it. The error itself isn't very clear, if I could get a line number pointed to, that would work.
class Dog {
int size;
String name;
void bark() {
if (size > 60) {
System.out.println(“Wooof! Wooof!”);
} else if (size > 14) {
System.out.println(“Ruff! Ruff!”);
} else {
System.out.println(“Yip! Yip!”);
[code]....
I am attempting to create a very simple game where two squares move around and each can see the other square moving. This is a multi-player game over a TCP network using JavaFX. I am getting an illegal state exception when I call requestFocus(). This is my server:
public class GameServer extends Application {
ObjectOutputStream p1out;
ObjectOutputStream p2out;
int PLAYER1 = 1;
int PLAYER2 = 2;
[Code] .....
Class A{
Public static synchronized void main(String args[]){
Thread t= new thread();
t.start();
Sysout("hi");
t.wait(1000);
Sysout("hello");
}}
Illegal state monitor exception. Why?
I've come across an interesting problem when using a Jcombobox as a custom cell editor(and renderer) in a jtable. I was hoping to add a keybinding in order to display the dropdown of the combobox instead of having to click on it however, when I make a call to showPopup() I get:
Exception in thread "AWT-EventQueue-0" java.awt.IllegalComponentStateException: component must be showing on the screen to determine its location Which is strange as my jtable is visible and the editor/renderer seems to be working fine.
Here's the cell editor + renderer I'm using:
class MyComboBoxRenderer extends JComboBox implements TableCellRenderer {
public MyComboBoxRenderer(String[] items) {
super(items);
} public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
boolean hasFocus, int row, int column) {
if (isSelected) {
setForeground(table.getSelectionForeground());
[code]....
I am working on a program that will allow a user to input grades for a class of four students who have taken two tests. Based on the grades entered, the program will calculate the averages of the two tests for each student and display it along with their respected letter grades.
Now I can get the program to compile successfully, but after inputting the grades in, I get the error message saying that it cannot format given object as a number. I am using 4 arrays to execute this program and maybe that's why I'm having the trouble? I'm not sure because I am still fairly new at this stuff and can't sen to resolve it.
I was having problems for a while and then finally got excited when I got it to compile without any errors and now I'm getting an error inside my program. All I need to do is format the numbers of the grades into something like: 000, and each of the averages as 000.0. I understand how to do it because I have done it in another program I've done in the past. I just don't know how to fix this error that is coming up.
here is my code:
import java.util.Scanner;
import java.text.DecimalFormat;
public class TestAverage
{
/**
* A program that will store and process 2 test scores for a class of 4 students.
* The program will prompt for the test scores as shown above in the sample run.
* After all the data is entered,the program will display the score for test 1, test 2 .
* The average of the 2 tests and the letter grade for the class for each student in a tabular format.
*
*
[code]....
I am getting Run time Exception while converting String object to Date Object ....
java.text.SimpleDateFormat@b9b195a0
java.text.ParseException: Unparseable date: "14-07-2012"
public static void main(String[] args) {
String time = "14-07-2012";
[Code] .....
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.
Hello World program. We had to build it. Write a basic Java program that will implement one class to store a state of a project. The class should have one property to store a textual name of the state. When a object of this class is created the initial state should be "Open".
1) Class should have one method next() which will move the project to the next step in the sequence: Open - In progress - Closed.If next method is called for a project in the Closed state it should do nothing.
2) Class should have a method close() which will move the project into the Closed state.
3) Class should have a method print() that will output a current state of the project.
Submit a java code file as your assignment. Do not hesitate to contact me if you have any troubles with the assignment.
I have been working on this thing for almost a week, and really don't have a clue on what to do. I know I have to use a string = open, and I know I have to create an object. I don't have a clue on how to do this. I have read the chapter so many times, I almost memorized it, but what he wants is nothing like our demo in the book. the Book used set and get, and utility scanner, but he doesn't want any of that. Just a basic code that will move from Open --- in progress --- closed.
The best I can tell what he wants is when I set the object to open it will display " project is open", then when I set it to " in progress" it will read project is "in progress". I don't have a clue what close is suppose to do, or the print method.
I am working in software testing, specifically automatic test cases generation. Among the existing forms of test cases, my focus is on the test cases that are composed of sequences of events such as _.event1.event2 eventx()
However, the events can be classified into: sensitive and insensitive. The latter does not affect the system's states, and hence, it can be ignored; while the former affects the states. Anyhow, the sensitive events in the test cases may lead to states explosion and there is a need to prevent that. Therefore, some techniques suggest using one variable to present states and group all similar states together such as using len variable in circular queue. Relatively, the states can be represented by using specific drawings such FSM.
For example, the test cases for circular queue may look like:
add(0).remove().add(1).Front()
add(0).add(1).remove().Front()
which produce the following states:
len=1, rear=0, front=0 and dataQ[0]=0
len=0, rear=0, front=1 and dataQ={0}
len=1, rear=1, front=1 and dataQ[1]=1
len=1, rear=0, front=0 and dataQ[0]=0
len=2, rear=1, front=0 and dataQ[1]=1
len=1, rear=1, front=1 and dataQ={1,0}
As can be seen, every addition/deletion produces a new state. A state is composed of 4 variables: len, rear, front and dataQ. The 1st three variables are integers while the dataQ is an integer array. Nonetheless, the states produced by different test cases can be identical which wastes effort and time. So, there is a need to optimize these states. The search techniques were suggested where the problem can be represented as a search problem and the technique is applied. If we consider Len as a state, then we will have: len=0; 0QSize. However, this does not represent the state but it suits for classifying the states into groups.
In terms of states representation, State Machine/Map Compiler (SMC) was suggested as a modeling mechanism that takes the state machines (i.e. FSM) drawing and generates the code in any preferred language. In SMC, the FSM is represented in a specific syntax (state---transition----next state) and saved in a file (.sm). This file will be compiled by SMC to generate a context class which includes definitions of states, transitions and actions in FSM but still need to be triggered by another class. This class has to call the transitions that modifies the state.
We had created that class and implemented all the methods with their transitions. However, the FSM used was based on 1 variable only (i.e. len). Besides, we are still looking for the SMC results as they will be the input for any search technique to be applied. Supposedly, the states generated by SMC can be used directly in the search technique but this is still questionable.
in my web.xml the.STATE_SAVING_METHOD setting is server
<context-param>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>server</param-value>
</context-param>
for measurement of application security isn't not allow to change this parameter to client , so the problem when I access for application and I open a new page via linker for print for example and I would access for my initial page to make change or modify my initial page it s no possible to make any modification because I have a empty bean , but if the state saving is a client I haven't a problem because a tree map is stored in client browser, so my version of JSF is 1.1.1 ,
I am using Java Swing to create a GUI. I have some radio buttons on a JFrame that gets opened when the user makes a certain selection. I want to read a config file to have the radio buttons selected or deselected when the form is opened to indicate the current state of the radio button based on the saved config file.
How do I go about setting the radio button as selected (visibly selected) when I open up the JFrame?
I was trying to use RadioButton.setSelected(True); but this doesn't actually visibly select the radio button.
When a thread completes its execution, it will be destroyed.In Java thread pool implemenation, how does threads come back to ready state after executing the task.?
View Replies View Relatedcode for extracting kerala state vehicle number plate from an image
View Replies View RelatedI would like to ask you about possibility to restore javafx 8 app from iconified mode (setIconified(true)) to regular size via shorcut for example: Ctrl + Shift + Ins I use Windows 7 and jdk 1.8.0_40 beta.
View Replies View RelatedI am new to OOP, i am not sure if this is the correct approach or not. Write a class named CreditCard that has (at least) the following member variables:
- name. A String that holds the card holder's name.
- cardNumber. A field that holds the credit card number.
- balance. A double that stores the current credit card balance.
- spendingLimit. A double that stores the spending limit of the card holder.
- Bonus: additional fields that you can think of.
In addition, the class should have the following member functions:
- Constructor. The constructor should accept the card holder's name and card number and assign these values to the object's corresponding member variables. The constructor should initialize the spending limit to $2,000 and the balance to $0.
- Accessors. Appropriate accessor functions should be created to allow values to be retrieved from an object's member variables.
- purchase. This function should add the amount specified as a parameter to the balance member variable each time it is called.
- increaseSpendingLimit. This function should add 500 to the spendingLimit member variable each time it is called.
- payBill. This function should reset the balance to 0.
- Input validation: Whenever a credit card number is modified, verify that it is of reasonable length.
Demonstrate the class in a program that creates a CreditCard object and allows the user to change and view the state of the credit card with a menu driven program.
View Card Information.
- Purchase an Item: ask the user the purchase amount and increase the card balance accordingly.
- Pay Bill: call payBill method to set the balance to 0.
- Increase Spending Limit: ask the user how much the spending limit should be, and call the increaseSpendingLimit function the appropriate number of times.
[CODE]
import java.io.*;
import java.util.Scanner;
public class CreditCard
{
Scanner input = new Scanner(System.in);
//data members
private String holderName;
private int cardNumber;
private int accountBalance;
private double spendingLimit;
[Code] ....
I was giving a quick skim to some tutorials on the internet where I have found the exception that is handled is also declared in the throws clause of the method wrapping the try-catch block. For a code representation consider the following:
public void methodName() throws IOException {
try {
...
} catch (IOException ex) {
.... TODO handle exception
}
}
Right, so I got this program. It takes input from the user and assigns it to fields on an object. But, it's meant to check the users input. If the user enters bad input, it's supposed to throw this exception. For each of these exceptions, theres a class specifically for it.
public class PayrollDemo
{
public static void main(String[] args)
{
Payroll pr = new Payroll ("Test Name", 234);
System.out.println("Current Employee Information.
");
System.out.println("Name: " + pr.getName());
System.out.println("ID: " + pr.getID());
System.out.println("Hourly Pay Rate: " + pr.getHourlyPayRate());
[Code] ....
And this is the exception class.
public class InvalidNameException extends Exception
{
/**
No-arg constructor
*/
public InvalidNameException()
{
super("Invalid name");
}
}
PayrollDemo.java:43: error: cannot find symbol
InvalidNameException.InvalidNameException();
^
symbol: method InvalidNameException()
location: class InvalidNameException
1 error
It's just meant to tell the user that they entered an invalid value, which would mean if they entered an empty string instead of a name.
I have a TrafficLightsManager Thread class that create one new CarTrafficLight object, and manage him by synchronized semaphore.
Unfortunetly the line sleep(5000); after the traffic1.WaitToRed(); never happenned, and the class jumps very quickly over the Red State.
I added the Message "!!!" before moving out from the Red State to the orange to check if the red exists at all and the result was positive - the red status entered and then I got the "!!!" message,but at the second that I accepting the message the red state turns into the orange state......
I don't get it!!!
package MyTzomet;
import java.awt.Point;
import javax.swing.JOptionPane;
public class TrafficLightsManager extends Thread {
CarTrafficLight traffic1;
ViewFrame frm;
[Code] .....
Create an equals method that takes an object reference and returns true if the given object equals this object.
Hint: You'll need 'instanceof' and cast to a (Geocache)
So far I have:
public boolean equals(Object O){
if(O instanceof Geocache){
Geocache j=(Geocache) O;
if (this.equals(j)) //I know this is wrong... but I can't figure it out
return true;
}
else return false;
}
I think I have it correct up to the casting but I don't understand what I'm suppose to do with the this.equals(). Also I'm getting an error that I'm not returning a boolean... I get this all the time in other problems. I don't get why since I have to instances of returning booleans in this. "returns true if the given object equals this object" makes no sense to me. I assume the given object, in my case, is 'O'. What is 'this' object referring to?
I 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]...
can a keyevent in java make the space ship and the laser too ?
View Replies View RelatedFor example I create an object like this:
BankAccount b = new SavingsAccount();
Now lets say that I want to access a method 'addInterest()' that is in the 'SavingsAccount' class I would have to do: '((SavingsAccount)s).addInterest();'
The question I have is why do I have to cast 'b' to SavingsAccount? Isn't the actual object reference of 'b' already an instance of 'SavingsAccount' class? How does the 'BankAccount' affect the object itself? I'm really confused as to what class is truly getting instantiated and how BankAccount and SavingsAccount are both functioning to make the object 'b'.
I don't understand why the object reference variable 'a' cannot be recast from a thisA object reference to a thisB object reference.Is it the case that once a reference variable is linked to a particular object type then it cannot switch object types later on.I am facing the Java Associate Developer exam soon and I am just clearing up some issues in my head around object reference variable assignment,
class thisA {}
class thisB extends thisA { String testString = "test";}
public class CastQuestion2 {
public static void main(String[] args) {
thisA a = new thisA();
thisB b = new thisB();
[code]....
I am trying to get this to where I can type in a name and it will search through each object and print back the corresponding object info.
Java Code:
import java.util.Scanner;
public class MyPeople {
public static void main(String[] args) {
Person[] p = new Person[] {
new Person("Chris", 26, "Male", "NJ", "Single"),
new Person("JoAnna", 23, "Female", "NJ", "Single"),
new Person("Dana", 24, "Female", "NJ", "Single"),
new Person("Dan", 25, "Male", "NJ", "Single"),
new Person("Mike", 31, "Male", "NJ", "Married") };
[code]....
Task:The main method of the class Things below creates an object called printer deriving from the class PrintingClass and uses that object to print text. Your task is to write the PrintingClass class.
Program to complete:
import java.util.Scanner;
public class Things {
public static void main(String args[]) {
String characterString;
Scanner reader = new Scanner(System.in);
PrintingClass printer = new PrintingClass();
System.out.print("Type in the character string for printing: ");
characterString = reader.nextLine();
printer.Print(characterString);
}
}
// Write the missing class here
Note: In this exercise the solution is part of a conversion unit where many classes have been declared. Because of this the classes are not declared as public using the public attribute.
Example output
Type in the character string for printing: John Doe
John Doe
My Class:
class PrintingClass {
public void print(){
System.out.println(characterString);
}
}