open a port on linux server

January 13th, 2010

=========================================
iptables -A RH-Firewall-1-INPUT -p tcp -m state –state NEW -m tcp –dport 3690 -j ACCEPT
=========================================
RH-Firewall-1-INPUT is the name of the chain, and change 3690 to the port number you expect.

make div align center

December 31st, 2009

use style as:
.style{margin-left:auto;margin-right:auto;}

or
.style{margin:0 auto;}
for short

ORACLE UTL_RAW.BIT_AND

December 1st, 2009

eg.
select to_number(UTL_RAW.bit_and(to_char(1), ‘3′)) from dual;

href and onclick method in ‘A’ tag

October 16th, 2009

How to invoke onclick method but not go to the page head.

1
<a href="#" onclick="javascript:jsMethod();return false;">a link</a>

create a swing application

September 11th, 2009
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import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
 
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JApplet;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.WindowConstants;
 
public class Test3 extends JApplet {
 
	public void init() {
		Container contentPane = getContentPane();
 
		Icon icon = new ImageIcon(ClassLoader.getSystemResource("swing.gif")); 
		JLabel label = new JLabel(icon);
//		java.net.URL codebase = getClass().getResource("../swing.gif");
//		JLabel label = new JLabel(new ImageIcon(codebase));
 
		contentPane.setLayout(new FlowLayout());
		contentPane.add(label);
	}
 
	public static void main(String args[]) {
		final JFrame f = new JFrame();
		JApplet applet = new Test3();
 
		applet.init();
 
		f.setContentPane(applet.getContentPane());
		f.setBounds(100, 100, 308, 199);
		f.setTitle("An Application");
		f.setVisible(true);
 
		f.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
 
		f.addWindowListener(new WindowAdapter() {
			public void windowClosed(WindowEvent e) {
				System.exit(0);
			}
		});
	}
}

how to read a url

September 1st, 2009
String s = request.getRequestURL().toString();
URL url = new URL(s);
BufferedReader bf = new BufferedReader(new InputStreamReader(url.openStream()));

use kill with awk

August 27th, 2009

kill `ps -ef | awk ‘{if($11~/WorkOrderProcessor/) print$2}’`

VI command – D & x

August 10th, 2009

D

The D command deletes from the cursor position to the end of the line. (D is a shortcut for d$.)

x

Often you want to delete only one or two characters. Just as r is a special change command to replace a single character, x is a special delete command to delete a single character. x deletes only the character the cursor is on.

VI command – dw&dd

August 9th, 2009

dw

dw deletes a word beginning where the cursor is positioned. Notice that the space following the word is deleted.

dd

The dd command deletes the entire line that the cursor is on. dd will not delete part of a line. Like its complement, cc, dd is a special command.

VI command – (~)

August 5th, 2009

~

Changing the case of a letter is a special form of replacement. The tilde (~) command will change a lowercase letter to uppercase or an uppercase letter to lowercase. Position the cursor on the letter whose case you want to change, and type a ~. The case of the letter will change, and the cursor will move to the next character.