Simplicity Java Crashcourse @simplejavacourse-blog - Tumblr Blog

okonrad

Public, Protected, Default, and Private?

Here’s a chart

Class Subclass Package World

Public Y Y Y Y

Protected Y Y Y N

Nothing Y Y N N

Private Y N N N

simplejavacourse-blog

I accidentally posted this from my main blog a while back.

#simple #java #public #private #protected #class

Libraries!

Libraries tend to involve a lot of just plain memorization. No tricks here.

One trick I do is adding a * to my import, which means all from this library.

If you want to work with a GUI you have to

import javax.swing.*;//This will include JFrame JPanel and many more

java.awt.*; is used for many graphics and keyboard tools

java.awt.event.*; is used for mouse events and key events and even button events.

java.util.*; is like the batman belt of Java I tend to use this with all real programming assignments because I just LOVE the ArrayList ^^

These are the ones I tend to use the most, but there are MANY MORE and it just takes time to learn the ones that apply to you.

#simple #java #library #class

Hey, what about something that uses an API, something like a simple Twitter tweeter app. And, welcome back :)

Sure thing, and thanks!Now just something that lets you log into your account, and send tweets in an input bar?Warning: This may be a series of tutorials, because I have to build you up to doing that.

NubecInfiniteArray

//We have to import the ArrayList class import java.util.ArrayList; //Making of a public class public class NubecInfiniteArray { //Main method public static void main(String[]args) { //We create a new ArrayList of Integers //Integers are different than ints //Integers can act like ints though ArrayList<Integer> list = new ArrayList<Integer>(); //We add an int 7,8,9 to the Array list.add(7); list.add(8); list.add(9); //We remove the 3rd element from the list //Remember we count like 0,1,2 list.remove(2); //A for each loop to print out all elements in the ArrayList //For Every Integer "i" in list // print "i" for(Integer i:list) System.out.println(i); } }

#simple #java #arraylist #class

#Simple #Java #Youtube #hello world #Class

KeyboardListener

import java.awt.*; import javax.swing.*; import java.awt.event.*; public class KeyboardEar { public static void main(String[]args) { JFrame window = new JFrame(); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); window.setSize(200,200); window.setLayout(null); JPanel box = new JPanel(); box.setBackground(Color.BLACK); box.setBounds(20,20,20,20); box.setFocusable(true); box.addKeyListener( new KeyAdapter() { public void keyPressed(KeyEvent e) { JPanel panel = (JPanel)e.getSource(); Point pos = panel.getLocation(); int x = (int) pos.getX(); int y = (int) pos.getY(); switch(e.getKeyCode()) { case(KeyEvent.VK_UP):panel.setBounds(x,y-5,20,20);break; case(KeyEvent.VK_DOWN):panel.setBounds(x,y+5,20,20);break; case(KeyEvent.VK_LEFT):panel.setBounds(x-5,y,20,20);break; case(KeyEvent.VK_RIGHT):panel.setBounds(x+5,y,20,20);break; } } } ); window.add(box); window.setVisible(true); } }

#Simple #Java #KeyEvent #KeyListener #Class

NubecArray

public class NubecArray { public static void main(String[]args) { //We create an Array of 10 ints int[]array = new int[10]; //Unless set otherwise all elements = 0; //We set the 4th element in the array to 9 array[3] = 9; //You have to start counting from 0 //We'll use a for each loop to cylce through the elements for(int x:array) System.out.println(x); } }

#Simple #Java #Array #Class

Challenge Present: Internet Browser!

import java.awt.*; import java.util.*; import javax.swing.*; import java.awt.event.*; import javax.swing.event.*; public class MyBrowser { private JFrame window; private JTextField urlBar; private JEditorPane display; public MyBrowser() { window = new JFrame("Krowser"); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); window.setLayout(new BorderLayout()); window.setSize(1000,700); urlBar = new JTextField("http://www.google.com/"); urlBar.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { load(e.getActionCommand()); } }); window.add(urlBar, BorderLayout.NORTH); display = new JEditorPane(); display.setEditable(false); display.addHyperlinkListener(new HyperlinkListener() { public void hyperlinkUpdate(HyperlinkEvent e) { if(e.getEventType()==HyperlinkEvent.EventType.ACTIVATED) load(e.getURL().toString()); } }); window.add(display, BorderLayout.SOUTH); window.setVisible(true); } public void load(String url) { try { display.setPage(url); } catch(Exception e) { //Nothing! } } public static void main(String[]args) { new MyBrowser(); } }

#Simple #Java #Internet #Browser #Class

Grabbing user input

import java.util.*; public class Scanning { public static void main(String[]args) { Scanner scanner = new Scanner(System.in); System.out.println(scanner.nextLine()); } }

#Simple #Java #Scanner #Class

Ideas for lessons!

I would appreciate some ideas as to what to teach you guys. I've installed disqus, so please leave a comment below!

Are you guys finding these tutorials useful?

Adding HTML to a window

import javax.swing.*; public class HTML { public static void main(String[]args) { JFrame window = new JFrame(); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); window.setSize(200,200); window.setLayout(null); JLabel label = new JLabel("<html><h1>Hello World!</h1></html>"); label.setBounds(20,0,200,50); window.add(label); window.setVisible(true); } }

#Simple #Java #HTML #Class

Teaches you how to make, compile, and run your first java project!

IDE's for different OS's

Windows: BlueJ, Notepad++

Linux: Geany

Mac:TextMate

#Simple #Java #Youtube #Class

To be continued then broken

public class ContinueAndBreak { public static void main(String[]args) { for(int i=0;i<10;i++) { if(i==4)continue; System.out.println(i); } System.out.println(); for(int i=0;i<10;i++) { if(i==4)break; System.out.println(i); } } }

#Simple #Java #Continue #Break #Class

Commenting and Youtube Uploads

I've decided against the Javadoc'ing process and will instead make Youtube videos. I will post the uploads as they come.

#Java #Youtube #Javadoc #Update

Commenting Update

So I'm going to work on giving all the codes Javadocs.

Javadocs aren't nessisary to the actual code itself, but it'll help you know what on earth is going on with this sorcery.

Think of Javadocs as fancy comments

#1st world problems #Java #Javadocs

JC-C-C-ComboBox!

import javax.swing.*; import java.awt.event.*; public class ComboBox { public static void main(String[]args) { JFrame window = new JFrame(); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); window.setSize(200,200); window.setLayout(null); String[]opts = {"Option 1","CheeseBurger","Taco"}; JComboBox<String> opt = new JComboBox<>(opts); opt.setBounds(25,60,150,25); opt.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { JComboBox cb = (JComboBox)e.getSource(); System.out.print(cb.getSelectedIndex()+": "); System.out.println(cb.getSelectedItem()); } }); window.add(opt); window.setVisible(true); } }

#Simple #Java #JComboBox #Class #Mortal Combat

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