import java.awt.BorderLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.IOException;

// Thrown when a URL doesn't contain http://

// and other rules like that

import java.net.MalformedURLException;

import java.net.URL;

// A text component that allows for rich text

// and basic html display

import javax.swing.JEditorPane;

import javax.swing.JFrame;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JScrollPane;

import javax.swing.JTextField;

// Provides information on events triggered

// through interaction with links

import javax.swing.event.HyperlinkEvent;

// Monitors user activity with links

import javax.swing.event.HyperlinkListener;

public class JavaLesson39 extends JFrame implements HyperlinkListener, ActionListener{

public static void main(String[] args){

new JavaLesson39("file:///Volumes/My%20Book/Presentations/HTML%20Tutorial/htmlexample.html");

}

String defaultURL;

JPanel toolPanel = new JPanel();

JTextField theURL = new JTextField(25);

// Displays basic html pages

// Doesn't understand JavaScript

JEditorPane htmlPage;

public JavaLesson39(String defaultURL){

JFrame frame = new JFrame("Java Browser");

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.defaultURL = defaultURL;

// If the user interacts with the JTextField the

// actionPerformed method is called

theURL.addActionListener(this);

// Set default text in the JTextField

theURL.setText(defaultURL);

// Add the text field to a panel

toolPanel.add(theURL);

// Add the panel to the northern quadrant of a frame

frame.add(toolPanel, BorderLayout.NORTH);

try {

htmlPage = new JEditorPane(defaultURL);

// If the user interacts with the JEditorPane

// actions are triggered. Ex. Click on a link

// change the JEditorPane page location

htmlPage.addHyperlinkListener(this);

// You can leave this true for rich text documents

// but it will mess up web page display

htmlPage.setEditable(false);

// Add the JEditorPane to a Scroll pane

JScrollPane scroller = new JScrollPane(htmlPage);

// Add Scroll pane and JEditorPane to the frame

frame.add(scroller, BorderLayout.CENTER);

}

// If something goes wrong with locating the html page

// this will handle that error

catch (IOException e) {

e.printStackTrace();

}

// Set size of the frame and display it

frame.setSize(1200, 800);

frame.setVisible(true);

}

public void hyperlinkUpdate(HyperlinkEvent e) {

// Checks if a link was clicked

// EventType.ENTERED : Checks for hovering

// EventType.EXITED : Checks for leaving link

if(e.getEventType() == HyperlinkEvent.EventType.ACTIVATED){

try {

// Sets the URL to be displayed

// getURL gets the URL for the link

htmlPage.setPage(e.getURL());

// toExternalForm creates a String representation of the URL

theURL.setText(e.getURL().toExternalForm());

}

catch(IOException e1){

e1.printStackTrace();

}

}

}

public void actionPerformed(ActionEvent e) {

String pageURL = "";

// Gets the Object that had an event triggered

if(e.getSource() == theURL){

// Get the text in the JTextField

pageURL = theURL.getText();

} else {

pageURL = defaultURL;

// Opens an alert box when an error is made

JOptionPane.showMessageDialog(JavaLesson39.this,

"Please Enter a Web Address", "Error",

JOptionPane.ERROR_MESSAGE);

}

try{

// Sets the URL to be displayed

htmlPage.setPage(new URL(pageURL));

theURL.setText(pageURL);

}

catch(MalformedURLException e2){

JOptionPane.showMessageDialog(JavaLesson39.this,

"Please use http://", "Error",

JOptionPane.ERROR_MESSAGE);

}

catch(IOException e1){

e1.printStackTrace();

}

}

}