String

Kelas FileChooserDemo

/*
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 * and open the template in the editor.
 */

package String;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import javax.swing.*;

/**
 *
 * @author admin
 */
public class FileChooserDemo extends JPanel
                             implements ActionListener {
    static private final String newline = "\n";
    JButton openButton, saveButton;
    JTextArea log;
    JFileChooser fc;

    public FileChooserDemo() {
        super(new BorderLayout());

        //Create the log first, because the action listeners
        //need to refer to it.
        log = new JTextArea(5,20);
        log.setMargin(new Insets(5,5,5,5));
        log.setEditable(false);
        JScrollPane logScrollPane = new JScrollPane(log);

        //Create a file chooser
        fc = new JFileChooser();

        //Uncomment one of the following lines to try a different
        //file selection mode.  The first allows just directories
        //to be selected (and, at least in the Java look and feel,
        //shown).  The second allows both files and directories
        //to be selected.  If you leave these lines commented out,
        //then the default mode (FILES_ONLY) will be used.
        //
        //fc.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
        //fc.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);

        //Create the open button.  We use the image from the JLF
        //Graphics Repository (but we extracted it from the jar).
        openButton = new JButton("Open a File...");
//                                 createImageIcon("images/Open16.gif"));
        openButton.addActionListener(this);

        //Create the save button.  We use the image from the JLF
        //Graphics Repository (but we extracted it from the jar).
        saveButton = new JButton("Save a File...");
//                                 createImageIcon("images/Save16.gif"));
        saveButton.addActionListener(this);

        //For layout purposes, put the buttons in a separate panel
        JPanel buttonPanel = new JPanel(); //use FlowLayout
        buttonPanel.add(openButton);
        buttonPanel.add(saveButton);

        //Add the buttons and the log to this panel.
        add(buttonPanel, BorderLayout.PAGE_START);
        add(logScrollPane, BorderLayout.CENTER);
    }

    @Override
    public void actionPerformed(ActionEvent e) {

        //Handle open button action.
        if (e.getSource() == openButton) {
            int returnVal = fc.showOpenDialog(FileChooserDemo.this);

            if (returnVal == JFileChooser.APPROVE_OPTION) {
                File file = fc.getSelectedFile();
                //This is where a real application would open the file.
                log.append("Opening: " + file.getName() + "." + newline);
            } else {
                log.append("Open command cancelled by user." + newline);
            }
            log.setCaretPosition(log.getDocument().getLength());

        //Handle save button action.
        } else if (e.getSource() == saveButton) {
            int returnVal = fc.showSaveDialog(FileChooserDemo.this);
            if (returnVal == JFileChooser.APPROVE_OPTION) {
                File file = fc.getSelectedFile();
                //This is where a real application would save the file.
                log.append("Saving: " + file.getName() + "." + newline);
            } else {
                log.append("Save command cancelled by user." + newline);
            }
            log.setCaretPosition(log.getDocument().getLength());
        }
    }

    /** Returns an ImageIcon, or null if the path was invalid. */
    protected static ImageIcon createImageIcon(String path) {
        java.net.URL imgURL = FileChooserDemo.class.getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL);
        } else {
            System.err.println("Couldn't find file: " + path);
            return null;
        }
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event dispatch thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("FileChooserDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Add content to the window.
        frame.add(new FileChooserDemo());

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event dispatch thread:
        //creating and showing this application's GUI.
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                //Turn off metal's use of bold fonts
                UIManager.put("swing.boldMetal", Boolean.FALSE);
                createAndShowGUI();
            }
        });
    }
}



Kelas RegexSubstitution

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package String;

/**
 *
 * @author admin
 */
public class RegexSubstitution {

    public static void main(String args[]) {
        String firstString = "Every day is sunday";
        String secondString = "Vini pergi ke pasar 3 jam lalu, bersama 4 temannya";

        System.out.printf("Original String 1: %s\n", firstString);
        firstString = firstString.replaceAll("\\bday\\b", "week there"); // jelaskan
        System.out.printf(
                "Original string 1 become : %s\n", firstString);

        System.out.printf("Original String 2: %s\n", secondString);//%s = diisi dengan string
        secondString = secondString.replaceAll("[a]", "o");//jelaskan
        System.out.printf(
                "Original string 2 become : %s\n", secondString);

        System.out.printf("Every word replaced by \"word\": %s\n\n",
                firstString.replaceAll("\\w+", "word")); // jelaskan

        secondString = secondString.replaceFirst("\\d", "digit");
        // jelaskan
        System.out.printf("?? %s\n", secondString); //isilah ?? dengan kalimat yang sesuai

        String output = "String split at commas: [";
        String[] results = secondString.split(",\\s*"); // jelaskan

        for (String string : results) // jelaskan sintaks ini
        {
            output += "\"" + string + "\", ";
        }
        System.out.println("Hasil split : " + output);
        output = output.substring(0, output.length() - 2) + "]";
        System.out.println(output);
    } // end main
}




Kelas StringConstructor
package String;

import java.util.StringTokenizer;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
/**
 *
 * @author admin
 */
public class StringConstructors {

    public static void main(String args[]) {
        char charArray[] = {'b', 'i', 'r', 't', 'h', ' ', 'd', 'a', 'y'};
        String s = new String("hello");

        String s1 = new String();
        String s2 = new String(s);
        String s3 = new String(charArray);
        String s4 = new String(charArray, 6, 3);

        System.out.println("s1 = " + s1);
        System.out.println("s2 = " + s2);
        System.out.println("s3 = " + s3);
        System.out.println("s4 = " + s4);

        if (s.equals("hello")) {
            System.out.println("s is equals as \"hello\"");
        } else {
            System.out.println("s is not equals as \"hello\"");
        }

        if (s.equalsIgnoreCase("HELLO")) {
            System.out.println("s is equals as \"hello\"");
        } else {
            System.out.println("s is not equals as \"hello\"");
        }

        System.out.println("Compare to : "+s.compareTo("hello"));
        System.out.println("Compare to : "+s.compareTo("hai"));

        if(s3.contains("day")) {
            System.out.println("s3 contains \"day\"");
        } else {
            System.out.println("s3 do not contains \"day\"");
        }

        String s5 = s.concat(" " + s3);
        System.out.println(s5);

        String s6 = s5.replaceAll("hello", "happy");
        System.out.println(s6);

        String[] s7 = new String[3];
        s7 = s6.split(" ");
        for (int i = 0; i < s7.length; i++) {
            System.out.println(s7[i]);
        }

        StringTokenizer tokens = new StringTokenizer(s6);
        System.out.println("Number of Token =" + tokens.countTokens());

        while (tokens.hasMoreTokens()) {
            System.out.println(tokens.nextToken());
        }

    }
}