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Thread: Character Count Frequently

  1. #1
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    Unhappy Character Count Frequently

    Hello, i'm new here. I want create a character count frequently using SWING.

    it's my code
    import java.awt.BorderLayout;
     
     
    public class CharacterCounter extends JFrame {
     
    	private JPanel contentPane;
    	private JTextField input;
    	private JTextArea output;
     
    	/**
    	 * Launch the application.
    	 */
    	public static void main(String[] args) {
    		EventQueue.invokeLater(new Runnable() {
    			public void run() {
    				try {
    					CharacterCounter frame = new CharacterCounter();
    					frame.setVisible(true);
    				} catch (Exception e) {
    					e.printStackTrace();
    				}
    			}
    		});
    	}
     
    	/**
    	 * Create the frame.
    	 */
    	public CharacterCounter() {
    		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    		setBounds(100, 100, 274, 258);
    		contentPane = new JPanel();
    		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    		setContentPane(contentPane);
    		contentPane.setLayout(null);
     
    		JLabel lblText = new JLabel("Text");
    		lblText.setBounds(34, 17, 70, 15);
    		contentPane.add(lblText);
     
    		input = new JTextField();
    		input.setBounds(77, 12, 164, 25);
    		contentPane.add(input);
    		input.setColumns(10);
     
     
     
    		JButton btnCalculate = new JButton("Calculate");
    		btnCalculate.addActionListener(new ActionListener() {
     
    			public void actionPerformed(ActionEvent arg0) {
     
    				String text = input.getText();
    				text = text.toLowerCase();
    				char [] character =  { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' };
    				int [] freq = new int [character.length];
     
    				for ( int i = 0; i < text.length(); i++ ){
    					for ( int j = 0; j < character.length; j++ ){
    						if ( text.charAt(i) == character [j]) {
    							freq[j]++;
    						}
    					}
    				}
    				for ( int i = 0; i < freq.length; i++ ){
    					if (freq[i] >= 1) {
    						output.append(character[i]+"="+ freq[i]+ "\n");
    					}
    				}
    			}
     
    			}
    		);
    		btnCalculate.setBounds(141, 46, 100, 25);
    		contentPane.add(btnCalculate);
     
    		JTextArea output = new JTextArea();
    		output.setBounds(34, 83, 93, 133);
    		contentPane.add(output);
    	}
    }

    I've got error message when try to show the character count in text area (variable = output). Anyone can help?


  2. #2
    Member snowguy13's Avatar
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    Default Re: Character Count Frequently

    It'd be nice if you could print the message of the error here, and be more specific in your question.

    One thing that comes to my mind is that fact that you use the append() method... Can you think of a simpler way to add to a String?
    Use highlight tags to help others help you!

    [highlight=Java]Your prettily formatted code goes here[/highlight]

    Using these tags makes your code formatted, and helps everyone answer your questions more easily!




    Wanna hear something funny?

    Me too.

  3. #3
    Administrator copeg's Avatar
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    Default Re: Character Count Frequently

    Quote Originally Posted by snowguy13 View Post
    One thing that comes to my mind is that fact that you use the append() method... Can you think of a simpler way to add to a String?
    Its the append method of a JTextArea, so I'm not sure what your getting at

    Quote Originally Posted by ndundupan
    I've got error message when try to show the character count in text area (variable = output). Anyone can help
    I can guess this is a NullPointerException, but for future reference always provide as much information as possible. Add some println's in there to see what is null, and have a close look at which instance variables may not have been instantiated.

  4. #4
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    Default Re: Character Count Frequently

    Thank for response my question. this almost resolve, the application using this code
    import java.awt.BorderLayout;
    import java.awt.EventQueue;
     
    import javax.swing.JFrame;
    import javax.swing.JPanel;
    import javax.swing.border.EmptyBorder;
    import javax.swing.JLabel;
    import javax.swing.JTextField;
    import javax.swing.JButton;
    import java.awt.event.ActionListener;
    import java.awt.event.ActionEvent;
    import javax.swing.JTextArea;
     
     
    public class CharacterCounter extends JFrame {
     
    	private JPanel contentPane;
    	private JTextField input;
    	private JTextArea output;
     
    	/**
    	 * Launch the application.
    	 */
    	public static void main(String[] args) {
    		EventQueue.invokeLater(new Runnable() {
    			public void run() {
    				try {
    					CharacterCounter frame = new CharacterCounter();
    					frame.setVisible(true);
    				} catch (Exception e) {
    					e.printStackTrace();
    				}
    			}
    		});
    	}
     
    	/**
    	 * Create the frame.
    	 */
    	public CharacterCounter() {
    		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    		setBounds(100, 100, 274, 258);
    		contentPane = new JPanel();
    		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    		setContentPane(contentPane);
    		contentPane.setLayout(null);
     
    		JLabel lblText = new JLabel("Text");
    		lblText.setBounds(34, 17, 70, 15);
    		contentPane.add(lblText);
     
    		input = new JTextField();
    		input.setBounds(77, 12, 164, 25);
    		contentPane.add(input);
    		input.setColumns(10);
     
    		output = new JTextArea();
    		output.setBounds(34, 83, 93, 133);
     
     
     
    		JButton btnCalculate = new JButton("Calculate");
    		btnCalculate.addActionListener(new ActionListener() {
     
    			public void actionPerformed(ActionEvent arg0) {
     
    				String text = input.getText();
    				text = text.toLowerCase();
    				char [] character =  { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' };
    				int [] frek = new int [character.length];
     
    				for ( int i = 0; i < text.length(); i++ ){
    					for ( int j = 0; j < character.length; j++ ){
    						if ( text.charAt(i) == character [j]) {
    							frek[j]++;
    						}
    					}
    				}
    				for ( int i = 0; i < frek.length; i++ ){
    					if (frek[i] >= 1) {
    						output.setText(String.valueOf(frek));
    //						output.append(character[i]+"="+ frek[i]+ "\n");
    					}
    				}
    			}
     
    			}
    		);
    		btnCalculate.setBounds(141, 46, 100, 25);
    		contentPane.add(btnCalculate);
     
    		contentPane.add(output);
    	}
    }

    but if i try to writing "welcome to java" and calculate it the result is there:
    009.jpg

    I want the result showing every character on every word. Sorry my english not good.

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