i rewrote this code from head first java book . but every time i try to compile it it gives me this exception
java.lang.ExceptionInInitializerError
Caused by: java.lang.RuntimeException: Uncompilable source code - simpleFrame is not abstract and does not override abstract method actionPerformed(java.awt.event.ActionEvent) in java.awt.event.ActionListener
at simpleFrame.<clinit>(simpleFrame.java:6)
how can i instantiate simpleFrame class if i shoild make it abstract?
public class simpleFrame implements ActionListener{
JFrame f;
public static void main(String[] args){
simpleFrame s = new simpleFrame();
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.
import java.io.Console; public class Introductions{ public static void main(String[] args){ Console console = System.console(); console.printf("Hello!My name is ---"); } }
Output :-
Compiling Introductions.java....... -----------OUTPUT----------- Exception in thread "main" java.lang.NullPointerException at Introductions.main(Introductions.java:5) [Finished in 2.2s with exit code 1]
I have a enum class which contains some string which i am comparing to a string i get from a user
Java Code:
public enum Compare { a, b, c, d, e, f } class SomeClass { String method(String letter){ Compare word= Compare.valueOf(letter); } } mh_sh_highlight_all('java');
Everything works fine but when I added a new word to it like "g" it throws the IllegalArgumentException ?
The requirement is to write a rectangle class and a test class, which include try-catch blocks and exception handling. Exceptions, involving try, catch, throw, throws, and finally commands,how to write a code about basic things, but in the test class, it gives me specific width and height so that i dont konw how to write a try-catch blocks an exception handling in this test class.There is my two classes, they are separated.
public class Rectangle { double width ; double height ; Rectangle(){ width = 1; height = 1;
I am validating an xml file using XQuery in Java using XQJ API. When the query is triggered it is giving the ClassNotFoundException for orai18n.text.OraCollator. I have placed the orai18n-collation.jar file in MANIFEST.MF file and it is loaded in to the class path.
Not sure on why it is giving the exception.
The JDK i am using JDK1.7 and application server is weblogic.
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 wrote a program that would play a game of Hangman. It plays the game but it keeps on bringing up a exception error. This is my class code
import java.util.ArrayList; class Assignment2Q4 { private final ArrayList<Character> guessList = new ArrayList<>(); private final char[] charArray; private final String secretWord; private int guesses;
[Code] ....
This is the output that is given:
Enter the secret word: pizza Guess a letter: d ????? Guess a letter:
[Code] .....
Also when I guess the first letter of the word correctly it stops the program without going further on with the guessing.
So I'm learning java having been using c#. I based this code off an example from class. It compiles fine with no errors, but I'm getting this:
Which model do you want? + Standard,Electrum,CurveHilted, or Tonfa Standard Exception in thread "main" java.lang.ClassNotFoundException: Standard at java.net.URLClassLoader$1.run(URLClassLoader.java:366) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method)
I have written a java applet. Few months before It was working all fine but my client has some other requirements now and I have to edit it. I am getting two problems:
1. I could not execute it on my local computer as it always gives "your security settings have blocked a local application from running". I have edited the settings from Control Panel but it is then started giving permission error on including permission in manifest file it started giving trusted library error and still it is not resolved.
2. Can I know how to work with third party library with applets. I have imported the library and uses its few classes but when I tried to load applet it always give no class definition found error. I have some ways mentioned online like use comma separated names for all the jars but no luck so far.
i want to list files from resources folder like this:
@ManagedBean public class galley implements Serializable { private List<String> list; @PostConstruct public void init() { list = new ArrayList<String>();
[Code] ....
but it give me a null pointer exception on fList .... The directory of resources is :
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 }
How do you declare methods for a class within the class whilst objects of the class are declared else where?
Say for instance, I have a main class Wall, and another class called Clock, and because they are both GUI based, I want to put a Clock on the Wall, so I have declared an instance object of Clock in the Wall class (Wall extends JFrame, and Clock extends JPanel).
I now want to have methods such as setClock, resetClock in the Clock class, but im having trouble in being able to refer to the Clock object thats been declared in the Wall class.
Is this possible? Or am I trying to do something thats not possible? Or maybe I've missed something really obvious?
Regarding the lifecycle of servlet , in headfirst servlet i can find :
You normally will NOT override the service() method, so the one from HttpServlet will run. The service() method figures out which HTTP method (GET, POST, etc.) is in the request, and invokes the matching doGet() or doPost() method. The doGet() and doPost() inside HttpServlet don’t do anything, so you have to override one or both. This thread dies (or is put back in a Container-managed pool) when service() completes.
How can I call the doGet method of the subclass from the superclass. i am not getting this .
I have a quick polymorphism question. I have a parent class and a sub class that extends the parent class. I then declare an array of parent class but instantiate an index to the sub class using polymorphism. Do I have to have all the same methods in the child class that I do in the parent class? Here is an example of what I mean.
public class ParentClass { public ParentClass(....){ } public String doSomething(){ } } public class ChildClass extends ParentClass { public ChildClass(....)
[Code] ....
Is polymorphism similar to interfaces where the child class needs all the same methods?
I have a program which runs perfectly fine in Eclipse. however, the same program after exporting to jar in desktop and then executing in cmd gives exception.
why is this difference.
in eclipse. it is built up 1.6 JDK and run using 1.6 JRE.
in CMD, it runs by 1.7 JRE.
can this JRE version make a difference. Technically should not i believe.
value1 = text1.getText(); value2 = text2.getText(); Connect c = new Connect(value1,value2); if(c.check()== true) { Menu start = new Menu(c.getID()); dispose();
[code].....
I get an error "unreported exception java.SQLException; must be caught or declared to be thrown" how can i solve this I have taken a few basic classes but never got to exceptions.
I want to encrypt and decrypt a txt file by using PGP.I completed my PGP Encryption.I'm getting an error in PGP Decryption. The error msg as follows
Quote:
Exception in thread "main" java.lang.IllegalArgumentException: Invalid PGP message at com.newpackage.bouncy.PGPUtils.getDataList(PGPUtil s.java:502) at com.newpackage.bouncy.PGPUtils.decryptFile(PGPUtil s.java:198) at com.newpackage.bouncy.PGPFileProcessor.decrypt(PGP FileProcessor.java:56) at com.newpackage.bouncy.Tester.testDecrypt(Tester.ja va:46) at com.newpackage.bouncy.Tester.main(Tester.java:61)
I am getting this error in the following line of my code.
PGPObjectFactory factory=new PGPObjectFactory(PGPUtil.getDecoderStream(is)); =>> Object obj=factory.nextObject();//here i am getting obj as null if (obj == null) { //System.out.println("Invalid PGP Message"); //System.exit(0);
So I've been working on this program to make tournament matches for beach volley.
First little info: (I'm Belgian so some words are Dutch) -Class Speler: has arraylist with information with which player already has been played (codesLijst) -Class Inschrijvingen: makes players sign up with their level and name -Class Wedstrijd: makes matches, checks with Inschrijvingen if the players already have played together. If so, gives message that they need to change partner. If not, makes them a team.
Now if I run the program with fresh players, none of them have had a partner, it works fine. If I make just one new team and the other already exists, it also works fine. It's when I make the two teams with existing records (to see whether they already played together), that the error comes.I know there's a lot of code duplicate, will clear out eventually, this is just a raw version.
CLASS SPELER
import java.util.ArrayList; public class Speler { private Wedstrijden wedstrijd; private Inschrijvingen inschrijving; private String naam, ploeg; private int setPunten, winPunten; private long time; private String code; private ArrayList<String> lijstCodes = new ArrayList<String>();
public static void main(String[] args) { float y = 7 * i; } }
It gives : Exception in thread "main" java.lang.NullPointerException : Line 5...Why is it giving NPE? Isnt the variable defaulted with 0.0f? Also, I am not performing any dot operation, it's just a multiplication operation.
