well,it is the easist way that I have found.
the following is my final code:
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import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import java.net.*;
public class SimpleScannerApplet extends JApplet {
// Declare the GUI components used by the applet
TextField portTextField = new TextField("25",5);
TextArea resultsTextArea = new TextArea(2,60);
JButton scanButton = new JButton("scan");
// JButton helpButton = new JButton("help");
JLabel helpLabel = new JLabel("warning:set the port to be null,you can stop the program!");
JLabel portLabel = new JLabel("port: ");
JLabel resultsLabel = new JLabel("result: ");
JPanel mainPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel topPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel bottomPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
public SimpleScannerApplet() {
// Layout the applet's components
Border etched = BorderFactory.createEtchedBorder();
// Add an etched border to the main panel
mainPanel.setBorder(BorderFactory.createTitledBorder(etched, "local port scanner"));
// Host and port fields in top panel
topPanel.add(portLabel);
topPanel.add(portTextField);
topPanel.add(helpLabel);
// Scan button and result field in bottom panel
bottomPanel.add(scanButton);
bottomPanel.add(resultsLabel);
bottomPanel.add(resultsTextArea);
// Add top and bottom panels to main panel
mainPanel.add(topPanel);
mainPanel.add(bottomPanel);
// Set up the button's event handler
scanButton.addActionListener(new Scanner());
// Add the main panel to the applet's content pane
getContentPane().add(mainPanel);
}
// The Scan button's event handler does the actual scanning
private class Scanner implements ActionListener {
// Declare fields used as scan parameters
InetAddress address;
int port;
// Handle the button's action event
public void actionPerformed(ActionEvent ev) {
new Thread(){
public void run(){
out("check parameters ...");
while(validParameters()) {
out("scannering...");
try {
// Try to connect to the host/port
Socket s = new Socket("localhost",port);
// No exception: SUCCESS
out(" "+s+"\n");
s.close();
}catch(Exception ex) {
// Could not connect
if(ex instanceof SecurityException) out(ex.getMessage());
else out("Port "+port+" is closed ");
}
try{
Thread t =Thread.currentThread();
Thread.sleep(1000);
}
catch(InterruptedException e) {System.out.println("thread has wrong"); }
}
}
}.start();
}
// Validate scan parameters
private boolean validParameters() {
try {
String portString = portTextField.getText();
// Convert the portString to an int
port = Integer.decode(portString).intValue();
// Make sure that it's in range
if(port > 65535) throw new ScannerException("Invalid port.");
}catch(Exception e) {
// Handle any validation-related exceptions
out(e.getMessage());
return false;
}
return true;
}
// Convenience method for writing results
private void out(String msg) {
resultsTextArea.setText(msg);
}
}
// Used to identify invalid scan parameters
private class ScannerException extends Exception {
public ScannerException(String msg) {
super(msg);
}
}
}
*********************************
the html code is:
**************
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"DTD/xhtml1-transitional.dtd">
<html>
<head><title>Local port scanner</title></head>
<body>
<div style="text-align: center">
<h1>Local port scanner</h1>
<applet name="ScanApplet" code="SimpleScannerApplet.class"
width="600" height="125">
Java not supported.
</applet>
</div>
</body>
</html>
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you could try it^_^
