Java IO.pdf - Nguyen Dang Binh

}
public void actionPerformed(ActionEvent evt) {
}
Java I/O
try {
URL u = new URL(theURL.getText());
InputStream in = u.openStream();
OutputStream out = theDisplay.getOutputStream();
StreamCopier.copy(in, out);
in.close();
out.close();
}
catch (MalformedURLException ex) {theDisplay.setText("Invalid URL");}
catch (IOException ex) {theDisplay.setText("Invalid URL");}
public void windowClosing(WindowEvent e) {
}
this.setVisible(false);
this.dispose();
public void windowOpened(WindowEvent e) {}
public void windowClosed(WindowEvent e) {}
public void windowIconified(WindowEvent e) {}
public void windowDeiconified(WindowEvent e) {}
public void windowActivated(WindowEvent e) {}
public void windowDeactivated(WindowEvent e) {}
public static void main(String args[]) {
}
URLViewer me = new URLViewer();
me.init();
The URLViewer class itself extends Frame. An alternative would have been to extend Panel,
which would have allowed URLViewer objects to be embedded in other containers. However,
this application seemed big enough to justify exclusive use of a window. URLViewer
implements the WindowListener interface to enable the user to close the window by clicking
in the close box. Only the windowClosing() method is nontrivial. The other six window
methods are do-nothing methods required to satisfy the contract of the WindowListener
interface.
The init() method builds the interface and displays the window. This is invoked by the
main() method, which constructs a new URLViewer object. The constructor is quite simple,
merely passing the title of the frame to the superclass constructor.
The streamed text area is filled when the user clicks the Load button or hits Return inside the
URL text field. The URLViewer object listens to both of these components. The URLViewer's
actionPerformed() method constructs a URL from the text in the text field, then opens an
input stream from the URL in the text field. Next, StreamCopier from Chapter 3 pours the
data from the URL's input stream into the text area's output stream. When that's finished, both
streams are closed.
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