NameSenderpublic class NameSender extends Applet implements Runnable
| Fields Summary |
|---|
| private Thread | pl | | private Button | send | | private TextField | t | | private String | str | | private Label | l | | private Label | l2 | | private DatagramSocket | s | | private InetAddress | hostAddress | | private byte[] | buf | | private DatagramPacket | dp | | private int | vcount |
| Methods Summary |
|---|
| public boolean | action(java.awt.Event evt, java.lang.Object arg)
if(evt.target.equals(send)) {
if(pl != null) {
// pl.stop(); Deprecated in Java 1.2
Thread remove = pl;
pl = null;
remove.interrupt();
}
l2.setText("");
// Check for errors in email name:
str = t.getText().toLowerCase().trim();
if(str.indexOf(' ") != -1) {
l.setText("Spaces not allowed in name");
return true;
}
if(str.indexOf(',") != -1) {
l.setText("Commas not allowed in name");
return true;
}
if(str.indexOf('@") == -1) {
l.setText("Name must include '@'");
l2.setText("");
return true;
}
if(str.indexOf('@") == 0) {
l.setText("Name must preceed '@'");
l2.setText("");
return true;
}
String end =
str.substring(str.indexOf('@"));
if(end.indexOf('.") == -1) {
l.setText("Portion after '@' must " +
"have an extension, such as '.com'");
l2.setText("");
return true;
}
// Everything's OK, so send the name. Get a
// fresh buffer, so it's zeroed. For some
// reason you must use a fixed size rather
// than calculating the size dynamically:
byte[] sbuf =
new byte[NameCollector.BUFFER_SIZE];
str.getBytes(0, str.length(), sbuf, 0);
DatagramPacket toSend =
new DatagramPacket(
sbuf, 100, hostAddress,
NameCollector.COLLECTOR_PORT);
try {
s.send(toSend);
} catch(Exception e) {
l.setText("Couldn't send datagram");
return true;
}
l.setText("Sent: " + str);
send.setLabel("Re-send");
pl = new Thread(this);
pl.start();
l2.setText(
"Waiting for verification " + ++vcount);
}
else return super.action(evt, arg);
return true;
| | public void | init()
setLayout(new BorderLayout());
Panel p = new Panel();
p.setLayout(new GridLayout(2, 1));
p.add(t);
p.add(send);
add("North", p);
Panel labels = new Panel();
labels.setLayout(new GridLayout(2, 1));
labels.add(l);
labels.add(l2);
add("Center", labels);
try {
// Auto-assign port number:
s = new DatagramSocket();
hostAddress = InetAddress.getByName(
getCodeBase().getHost());
} catch(UnknownHostException e) {
l.setText("Cannot find host");
} catch(SocketException e) {
l.setText("Can't open socket");
}
l.setText("Ready to send your email address");
| | public void | run()
try {
s.receive(dp);
} catch(Exception e) {
l2.setText("Couldn't receive datagram");
return;
}
l2.setText(new String(dp.getData(),
0, 0, dp.getLength()));
|
|
