I want to know if there is any general rule/pattern about things which give compilation fails and things which go for Runtime error/exception. OR only way is to remember all of them and there is no actual pattern in it.
I am trying to make a game, for some reason i have begun to get a java.lang.StackOverflowError.
I am not exactly sure how i can fix it. only removing line 14 from infopannel1 (and everything that used that class.) seems to work. im not sure what else i can do to fix it. or why its resulting in stack overflow for that matter.
I am putting in a link for the files i wrote this using bluej (several classes have no relevance, errorv2, demonstration, folderreadertest, ReadWithScanner, saveloadtest, menutest,rannum, and menutestTester. are all irrelivent to my problem.)
I came across this code which proves that variable initialisation occurs before even constructors are called.However, I am confused over some things.
Firstly, from my understanding, when a new House object is created in this line House h = new House(); , the no-arg constructor of the House class is called.
Since the no-arg constructor House() is called, why are all the creation of Window objects being run first ? Shouldn't Java jump straight into the no-arg constructor House() ?
class Window { Window(int marker) { System.out.println("Window(" + marker + ")"); } } class House { Window w1 = new Window(1); // Before constructor House() { // Show that we’re in the constructor: System.out.println("House()"); w3 = new Window(33); // Reinitialize w3
I am using netbeans 7.2, glassfish 3.1.2, JSF 2.1 and Primefaces 3.2. When I add more than three menu tabs, I get this error ui layout initialization error the center-pane element does not exist the center-pane is a required element. This is my template.xhtml code:
<?xml version='1.0' encoding='UTF-8' ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:h="http://java.sun.com/jsf/html" xmlns:p="http://primefaces.org/ui">
public class SavingsAccount extends Account { private static final double MIN_BALANCE = 100.00; private static final double RATE = 0.035; public SavingsAccount(Customer customer, double bal, String accountNum, Transaction[] trans) { super(customer, bal, accountNum, trans);
[code]....
When I execute this code there is an error in Transaction array initialization. Change the Saving account constructor from (String customer,double balance, String accountnumber,Transaction[] tr) to (String customer,double balance, String accountnumber,Transaction tr)
public static void main(String... args) { String i; // String i = null; that would compile if (i == null) {// this line does not compile as i was not initialized System.out.print("A"); } else { System.out.print("B"); i = "A"; main("A", "B"); } }
Why does the above code not compile although the statement String i should lead to an initialisation of i to the value of null which is the default value for Strings.
Now If I hit /Allen it sets init parameter for both servlet MyServlet and jsp JjspInit. I don`t have any servlet all I have is a web.xml and a jsp page. But accessing JjspInit.jsp directly gives null.
How hiting the url /Allen prints valu. This code is on JjspInit.jsp .
So does that mean that in web.xml I have registered this jsp as the target for /Allen. And one more question directly accessing the jsp page shows null it means init parameter haven`t been set.
if, instead of an ArrayList, can I do the following to initialize a Dyanmic array ? :
First, in my class, I have :
class Example{ private int rows; private int columns; private AnotherClass[][] 2DArray; public Example(int rows, int columns){ this.rows = rows; this.columns = columns;
Now if I am in the admin 1 environment, I would initialize my servlet with request parameter admin=1 and the servlet should load email address of admin 1 and similarly when in the environment 2, should load the servlet with admin 2.
I could do the same by putting the email address of the respective admin as request param value, but i don't want to the email address to appear in the url.
class A { final Object b; public A(C c) { try { b = c.someMethodThatMayThrowSomeException(); } catch (SomeException e) { b = null; // This line results in compiler error: "variable b might already have been assigned" } } // take away b=null line and you get "variable b might not have been initialized" on this line }
Why? How could 'b' be assigned if the exception was thrown?
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package vecchiogiovane; import java.io.*; public class Vecchiogiovane { /** * @param args the command line arguments */ public static void main(String[] args) throws Exception{
[Code] .....
run:
run:
ins first name: aldo ins first age: 35 ins second name:
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */
I've been trying to finish this blackjack program I have been making for my programming class, however, there are a few bugs I can't seem to iron out. It's a pretty short program, it's just that I'm an idiot and can't figure basic stuff like this out. Specifically, when I try and run it, I get this error:
Error occurred during initialization of VM java.lang.OutOfMemoryError: unable to create new native thread
I noticed it is a huge success to have the backgrounds of games move and the character just move up and down and dodge obstacles.How Do I make a background that scrolls horizontally to the left? I know how to keep the character in place with up and down to move, but not sure how to go about making the background move with obstacles.
1. I read somewhere that instead of looping through every player (below), you use could Events to do it for you:
for (Player player : this.getPlayers()) { if (player.getLocation().getX() == 10) { } }
I'm not sure as to how to use Events in place of a for loop. I've been thinking on this for days, but I'm still stuck. Any example of using an Event instead of a for loop?
2. Is there any way to accept multiple connections on a server without using a while loop? Maybe use Events to handle the acceptance of connections?
Is it possible to enable & disable "jdk.certpath.disabledAlgorithms" property programmatically. I want to remove all disabled Algorithms for some time and later I will enable it.
Or is it possible to enable only for a particular place & not in a JVM level. I want that Algorithm need to be enabled for a piece of code, but I don't want it to the remaining part of the application.
I am making a Dice Roll GUI and I have most of it down and I only need this constructor to work for the program to work (I think). I don't know where to place the constructor, I tried placing it around the RollButton class but it still didn't work and gave me java error constructor in class cannot be applied to given types
Here's my constructor:
private JPanel panel; public RollButton(JPanel panel){ this.panel = panel; }
I am currently trying to solve a programming problem on this site, and the problem includes working on a 100 digits of decimal places of a certain irrational number. I tried using BigDecimal class but it displays, correctly me if I am wrong, just 20+ decimal digits. Is there other way to do this?
