I'm just starting out in java and trying to use some example code I found online to get started, but for some reason, I am unable to compile this code. I on Ubuntu 16.04 and I have the "default-jdk" installed.
Here's the code:
import java.awt.*;
import java.awt.event.WindowListener;
import javax.swing.*;
import java.io.*;
public class Test extends JFrame{
public static void main (String argv [])
{
new Test("Window Application");
}
public Test(String title)
{
super(title);
setSize(200, 100);
addWindowListener((WindowListener) new WindowDestroyer());
setVisible(true);
}
private class WindowDestroyer extends WindowAdapter
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
}
When I try doing javac Test.java I get 2 cannot find symbol errors.
private class WindowDestroyer extends WindowAdapter
public void windowClosing(WindowEvent e)
From the Java 8 docs for WindowAdapter, it is defined as java.awt.event.WindowAdapter.
You need to import the class first:
import java.awt.event.WindowAdapter;
in addition to your other imports.
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowListener;
As a side note, you might be tempted to just do
import java.awt.event.*;
to avoid import errors like that in the future.
I suggest reading the discussions on Why is using a wild card with a Java import statement bad? to have an idea on the pro's and con's of doing so.
I can see, that you create simple Swing application window and close it close window. You do it in incorrect way. It is much better to use setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE) (only if you not plan to do smth. special before). And use SwingUtilities.invokeLater() to execute asynchronously on the AWT event dispatching thread:
public class Test extends JFrame {
public static void main(String... ars) {
SwingUtilities.invokeLater(() -> new Test().setVisible(true));
}
public Test() {
super("Window Application");
setSize(200, 100);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}
Related
Everything works in the program when the libraries with import javax.swing.* and import java.awt.*,but it doesn't work when something from these libraries is typed that doesn't offer awt and swing options in drop-down menu.
Example:
import javax.swing.*;
import java.awt.*;
public class MainFrame extends JFrame{
public static MainFrame instance = null;
private MainFrame() {
inicijalizacija();
}
private void inicijalizacija() {
Toolkit kt=Toolkit.getDefaultToolkit();
Dimension velicina=kt.getScreenSize();
int visina=velicina.height;
int sirina=velicina.width;
setSize(visina/2,sirina/2);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setTitle("GeRuDok");
}
public static MainFrame getInstance() {
if(instance==null) {
instance=new MainFrame();
}
return instance;
}
}
e.g Toolkit cannot be released here as awt, but offers it as com.sun.javafx.tk and like others(Dimension,getScreenSize...)
I thought it had something to do with the content assistant, but it doesn't work either.
It may have something to do with the Java version 1.8 that the project is in, but I really have no idea how to fix it.
I'd appreciate it.
I have the following question: I am trying to execute the usConstitution wordcram example (code follows) and if provided as is the code executes in eclipse, the applet starts and the word cloud is created. (code follows)
import processing.core.*;
//import processing.xml.*;
import wordcram.*;
import wordcram.text.*;
import java.applet.*;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.event.MouseEvent;
import java.awt.event.KeyEvent;
import java.awt.event.FocusEvent;
import java.awt.Image;
import java.io.*;
import java.net.*;
import java.text.*;
import java.util.*;
import java.util.zip.*;
import java.util.regex.*;
public class usConstitution extends PApplet {
/*
US Constitution text from http://www.usconstitution.net/const.txt
Liberation Serif font from RedHat: https://www.redhat.com/promo/fonts/
*/
WordCram wordCram;
public void setup() {
size(800, 600);
background(255);
colorMode(HSB);
initWordCram();
}
public void initWordCram() {
wordCram = new WordCram(this)
.fromTextFile("http://www.usconstitution.net/const.txt")
.withFont(createFont("https://www.redhat.com/promo/fonts/", 1))
.sizedByWeight(10, 90)
.withColors(color(0, 250, 200), color(30), color(170, 230, 200));
}
public void draw() {
if (wordCram.hasMore()) {
wordCram.drawNext();
}
}
public void mouseClicked() {
background(255);
initWordCram();
}
static public void main(String args[]) {
PApplet.main(new String[] { "--bgcolor=#ECE9D8", "usConstitution" });
}
}
My problem is the following:
I want to pass through main (which is the only static class) an argument so as to call the usConstitution.class from another class providing whichever valid filename I want in order to produce its word cloud. So how do I do that? I tried calling usConstitution.main providing some args but when I try to simply print the string I just passed to main (just to check if it is passed) I get nothing on the screen. So the question is How can I pass an argument to this code to customize .fromTextFile inside initWordCram ?
Thank you a lot!
from: https://wordcram.wordpress.com/2010/09/09/get-acquainted-with-wordcram/ :
Daniel Bernier says:
June 11, 2013 at 1:13 am
You can’t pass command-line args directly to WordCram, because it has no executable.
But you can make an executable wrapper (base it on the IDE examples that come with WordCram), and it can read command-line args & pass them to WordCram as needed.
FYI, it’ll still pop up an Applet somewhere – AFAIK, you can’t really run Processing “headless.” But that’s usually only a concern if you’re trying to run on a server.
I'm a beginner in Java and I followed a tutorial to write this program (yes, I that much of a beginner) and it works perfectly when I run it on Eclipse. It also runs great on the computer I coded it on. However, if I send it to another computer (just the .jar file) and run it, it fails because it can't find the icon. Here is everything I've got. The icon I'm using is saved in the bin folder along with all the class files for the program. For privacy reasons, I replaced certain lines with "WORDS".
The tutorial I followed in two parts:
Part 1 - https://buckysroom.org/videos.php?cat=31&video=18027
Part 2 - https://buckysroom.org/videos.php?cat=31&video=18028
My main class (I called it apples cause the tutorial did).
import javax.swing.JFrame;
public class apples {
public static void main(String[] args) {
Gui go = new Gui();
go.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
go.setSize(1920,1080);
go.setVisible(true);
}
}
And now my second class, "Gui":
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JOptionPane;
public class Gui extends JFrame {
private JButton custom;
public Gui () {
super("WORDS");
setLayout(new FlowLayout());
Icon b = new ImageIcon(getClass().getResource("b.png"));
custom = new JButton(null, b);
custom.setToolTipText("WORDS");
add(custom);
HandlerClass handler = new HandlerClass();
custom.addActionListener(handler);
}
private class HandlerClass implements ActionListener {
public void actionPerformed(ActionEvent event) {
JOptionPane.showMessageDialog(null, String.format("WORDS", event.getActionCommand()));
JOptionPane.showMessageDialog(null, String.format("WORDS", event.getActionCommand()));
JOptionPane.showMessageDialog(null, String.format("WORDS", event.getActionCommand()));
JOptionPane.showMessageDialog(null, String.format("WORDS", event.getActionCommand()));
}
}
}
Thank you so much for helping!
It's worth reading Loading Images Using getResource where it's explained in detail along with loading images from jar as well.
You can try any one based on image location.
// Read from same package
ImageIO.read(getClass().getResourceAsStream("b.png"));
// Read from src/images folder
ImageIO.read(getClass().getResource("/images/b.png"))
// Read from src/images folder
ImageIO.read(getClass().getResourceAsStream("/images/b.png"))
Read more...
I am java newbie.
I was reading a tutorial book, and tried almost all code given as examples, and they all worked perfectly. But, when I tried this audio playing tutorial, even though I understood most of it, I still can't make it play. It gives me error, saying
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
at MouseClicker.main(MouseClicker.java:9)
Here is the code.
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.applet.*;
import java.net.URL;
public class MouseClicker extends Jframe{
AudioClip click;
public static void main(String[] args){
new MouseClicker();
}
public MouseClicker(){
this.setSize(400,400);
this.setTitle("Mouse Clicker");
this.addMouseListener(new Clicker());
URL urlClick = MouseClicker.class.getResource("hello.wav");
click = Applet.newAudioClip(urlClick);
this.setVisible(true);
}
private class Clicker extends MouseAdapter
public void mouseClicked(MouseEvent e){
click.play();
}
}
public class MouseClicker extends Jframe{
It's a JFrame, not a Jframe. (capital F)
Remember, Java is case sensitive!
You're missing an opening brace in the definition of the Clicker class
private class Clicker extends MouseAdapter {
^
A Java IDE can highlight these syntax errors.
Also ensure that the audio file hello.wav is located in the same location as MouseClicker.class (the bin folder in this case) so that it can be read as a resource.
Can someone convert this into Clojure, I don't know to do the line setMainWindow(argument) like things....
import com.vaadin.Application;
class something {
public void init() {
Window main = new Window("The Main Window");
setMainWindow(main);
addComponent(new WindowOpener("Window Opener", main));
}
}
Update:
package app;
import com.vaadin.Application;
import com.vaadin.ui.Button;
import com.vaadin.ui.Window;
/**
* The Application's "main" class
*/
#SuppressWarnings("serial")
public class MyVaadinApplication extends Application{
private Window window;
#Override
public void init(){
window = new Window("My Vaadin Application");
setMainWindow(window);
window.addComponent(new Button("Click Me"));
}
}
There is a "/lib/vaadin.jar" which contains all "com.vaadin.*" things.
I think setMainWindow(window); is from the extended class. I am not going to write that method.
Literal translation:
(defn init []
(let [main (Window. "The Main Window")]
(setMainWindow main)
(addComponent (WindowOpener. "Window Opener" main))))
Though it doesn't make much sense without the context.
See http://dev.vaadin.com/wiki/Articles/ClojureScripting. Also I would suggest http://www.odesk.com.