I get no errors but the gui is not displaying
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package part1;
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import javax.swing.*;
class brick {
[Code] ....
I have a question about a method I have. In my game, I had a move method to move my player left and right, and originally this method was huge, as it also took care checking collisions and a few other things. I broke it up a bit and put the collisions in their own methods and call them from again another method... Here is an extract which I hope illustrates my point:
private static final double MOVE_SPEED = 0.2;
private static final double MAX_MOVE_SPEED = 3.5;
private static final double STOP_SPEED = 0.18;
private double xPos;
private double yPos;
[Code] .....
Something I thought might be a good idea is to check the direction collision when im doing the calculations for that direction:
if(moveLeft) {
dx -= MOVE_SPEED;
(dx < -MAX_MOVE_SPEED) {
dx = -MAX_MOVE_SPEED;
}
checkLeft();
}
But then I would also need to check it when I'm slowing down the left movement:
if(dx < 0.0) {
dx += STOP_SPEED;
if(dx > 0.0) {
dx = 0.0;
}
checkLeft();
}
Then I thought instead i can check it after both of these steps:
if(moveLeft || dx < 0.0) {
checkLeft();
}
I guess my question is quite general: How much is acceptable to break up a method? How many chains of method calls is acceptable? Is it ok to call the same method from different nearby places?
I don't know how to write a code to pong ball, when it touch red block.
public class bounc2 extends JPanel implements ActionListener,KeyListener{
double x = 0,y=0,velX=3,velY=3;
double x2 = 5,y2=145,velX2=0,velY2=0;
double x3= 473,y3=145,velX3=0,velY3=0;
Timer t = new Timer(5,this);
public bounc2(){
setBackground(Color.GREEN);
[Code] .....
package memorygame;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import java.util.Random;
import java.awt.*;
public class MemoryGame extends JFrame{
[Code]...
Is it a best practice to return from try block or place return statement after try-catch when we intend to return a value from a method(* Catch block is being also used to rethrow the exception)??
View Replies View RelatedI'm doing project in area of "Cryptography and Network security". I'm having a file with binary Unicode (mean file contain Unicode value of corresponding data (text file)), want to divide that as blocks with the size of 144bits.
View Replies View RelatedModify the program in Assign4 to synchronize access to the instance variable, balance. Save the program as SyncBank.java. Because balance is a double and not an object, it cannot be used as the monitor. Use synchronized methods or synchronized blocks of code as appropriate. Simultaneously test two threads as was done in Assign4. Because the threads can complete too quickly to determine if they are interfering with each other, delay the adding of a deposit by inserting the following code within the synchronized block or method:
try {
Thread.currentThread().sleep(10000); //sleep for milliseconds
}
catch(InterruptedException e) {
}
My code attempt so far:
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import java.net.*;
import java.text.DecimalFormat;
public class SyncBank extends HttpServlet //throws ServletException, IOException
[Code] .....
why Static Block in java executes first than the main block?
what is specific reason??
I'm suppose to read the following code and devise a program that can break the lock.
public class InsecurePasswordLock {
private char[] secret;
private boolean unlocked;
public InsecurePasswordLock() {
// secrets are usually 30 to 50 upper case characters long
// but here's a hard coded example one
secret = "ASECRETTHATYOUWILLNOTGUESSTODAY".toCharArray();
[Code]....
So, I believe that I can try various password lengths until I get a return from open that !=-1. But I'm not sure how to implement this. This is what I have so far to get the length:
public char[] breakLock(InsecurePasswordLock lock) {
int checkCount=1;
int length=0;
while(checkCount!=-1){
for(int i=0;i<=25;i++){
char[] key = new char[i];
if(InsecurePasswordLock.open(key)!=-1){ // I get a fault at this line for calling a static method
length=i;
checkCount=-1;
}
}
}
I get the error:
Cannot make a static reference to the non-static method open(char[]) from the type InsecurePasswordLock..
How can I keep querying the open method to get my length??
I'm trying to figure out how to read in an integer and break it down into a sequence of individual digits in reverse order. Example: an integer input of 12345 gives an output of54321.
View Replies View Relatedso I have a Text File that looks like this:
JohnGibson9127OakDrCorvallisOR973305552812313156.78
RonWills1155IvyPlAtlanticGa373395552123145189.56
RitaJones1259ChaseAveLas VegasNV8712655544456712145.60
JasonKnight7154PineDrGresjam OR9738055581245453157.44
ClaraSwanson1944MainPlSpringfieldCA973395552123144212.99
it has first name tab, last name tab, so on I'm saying this because it kept changing format but they are Tabs betwwen each word.
I need to print it in the correct order, so I will need to break this down into objects such as FirstName, LastName,Adress ect. I don't know how to break it into pieces. here is my code thus far:
import java.io.*;
import java.util.Scanner;
public class Postal
{
[Code]....
in which while loop do I add these variables, and could i get a example of how to do one, like first name?
You are given 2 files - "testcase.txt" and "validwords.txt".In testcase.txt, the sentences are written without any space inbetween/for ex: this is a sentence which looks ambigous.You are to insert a space at the proper place by breaking the sentence into correct words, ex o/p: this is a sentence which looks ambigous.validwords.txt contains all valid words (as 1 word per line). If you find a word that does not match, replace it with ####. After correcting
View Replies View Relatedhow to display a jpg image on a through a Jlabel. I am sure it is a simple error but I am still new to GUI's. line 31 to 35 you can see the ImageIcon and file wrapped in the JLabel. I verified its in the correct location and file name, but usually fails (i thought) when it is not correct.
Java Code:
import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
[code]....
my web browser isn't displaying any web page. When I create the method editorPane.setPage(), it takes forever (about 20 seconds) to show nothing. It'll load the web browser after the 20 seconds of waiting. Here is my code:
public class Browser extends JInternalFrame {
/**
*
*/
private static final long serialVersionUID = 4589041456161585394L;
public Browser() {
super("Browser", true, true);
this.setLayout(new BorderLayout());
this.setVisible(true);
this.setSize(Desktop.getSingletonInstance().getWidth(), Desktop.getSingletonInstance().getHeight());
[code]....
my java applet - displaying output with text
View Replies View RelatedI keep getting an error in my browser:
java.lang.IllegalArgumentException: argument type mismatch
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
[Code] .....
I see the file "myApache.log" got created but there's no info in it when i re-test the error, I have other existing appenders and categories in this same file which do give output so I know it has nothing to do with the file or the path itself.
I developed a simple java gui . On running a frame opens with 5 buttons and each button opens another frame when selected. There are no errors and frames open and close as required however i see that only the main program frame has the icon and title that i assigned and the frames bieng called through the buttons have the default frame with java icon and no title although it's been specified in the code of these called frames. When these called frames are executed individually though the program the title and icon are displayed.
View Replies View RelatedI have been given a task to scan the contents of a websites source code, and use delimiters to extract all hyperlinks from the site and display them. We havent been told anything about how to do this so after some looking around online this is what I have so far:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Scanner;
[Code] ....
So my program can extract each line from the source code of a website and display it, but realistically I want it to extract each WORD as such from the source code rather than every line. I've looked around online but I don't really know how it's done because I keep getting errors when I use input.read();
How to make it extract each word from the source code?
I have written some error checking code
File name ErrorPage.jsp
<%@ page language="java" isErrorPage="true" 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">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Error</title>
</head>
[code]...
I have put error.jsp and badpage.jsp file in public access folder that is web content in eclipsewhen I am running the code I am status code of 500 and not the errorpage.jsp message .
I have used FileInputStream class but its not working properly to divide the bits into blocks.I will attach the coding
public static void main(String[] args) {
ReadFileExample newclass = new ReadFileExample();
System.out.println("cryptography");
[Code].....
In the following piece of code Iam confused as to where the InputMismatchException in the catch block is thrown on the first place? Is the InputMismatchException thrown automatically with declaring to throw the exception?
import java.util.*;
public class InputMismatchExceptionDemo {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
boolean continueInput = true;
[code]....
Regarding return statements within methods. So I have a method containing try and catch block (as required) and much like when you have an if else statement... I noted you have to return an object for both the try and catch blocks. Now in my case my method should return a List object.
The way I have tried to overcome this:
- I've initialised a List object to null as an attribute of the class I'm working in.
- Therefore in the catch block would just simply return the null List object, where as the try block would return the non-empty List (which is what I want).
- I then just test to see if the List != null, when the method is invoked... and that is that.
However the method always seems to return null (when it shouldn't).
I can make my program print block letters out in a vertical format but I need them to come out in a horizontal format.
public class MISSISSIPPI {
public static void main(String[] args) {
drawM(); drawI(); drawS(); drawS(); drawI(); drawS(); drawS(); drawI(); drawP(); drawP(); drawI();
}
How would I get those methods to come out in a horizontal fashion instead of vertical?
It's always good to keep functions smaller and focused on one behavior. So is this safe:
Java Code:
public Unit findBySql(int id){
Unit unit=null;
DbConnectionPool dbPool = DbConnectionPool.getInstance();
HashMap<String, String> conditions = new HashMap<String, String>();
conditions.put("id", String.valueOf(id));
String sql = buildSelect("units", "*", conditions);
[Code] ......
As you can see a pass ResultSet to a function which populates the item. But I also make sure that the ResultSet that the passed object is pointing to is closed, so it doesn't leak resources.
I am developing a Client/Server java application, where CSMessage is sent through socket.CSMessage has some data like String type and HashMap<String, String> type.the Client send message:
private ObjectInputStream in;
private ObjectOutputStream out;
out = new ObjectOutputStream(socket.getOutputStream());
in = new ObjectInputStream(socket.getInputStream());
[code]....
When this happen, the only way to make the system to work is to kill the process and restart it, that's bad!
My current lesson in Java is about ArrayLists and I'm having a tough time to understand this bit of code: This exercise is concerned with the problem of deleting a block of items from an ArrayList.
public static void deleteBlock( ArrayList<String> strings, int n )
{
for ( int i = 0; i < n; i++ )
{
if ( strings.size() > 0 )
strings.remove( i );
[Code] ....
This is the output: [rosion, sion, on, n]