VPN configurations for internet addicts

Preamble :

One of my friends have blogged on how he managed to connect via VPN and to generic internet in parallel.

http://tdevinda.blogspot.com/2009/11/whats-inside-what-virtualization.html

This ended up in bringing a nice discussion on routing, VPN and VMs.

Following is my solution.


Issue :

Under normal conditions; when you get connected to a VPN, it is not possible to get connected with the internet.

Reason:

When you get connected to the VPN, automatically it is set as the default route.


Solution:

1. Once you are connected to VPN, remove the default route for VPN. Under linux vpn is normally tun0.
2. Then add a default entry for your usual network interface. (eth0, ppp0, etc)
3. Then add the routing entry for the specific IP or the subnet which you need to get connected through VPN for tun0

Installing IE 8

Installed IE 8 in my office pc. (Yes I do use Fedora in my laptop, but the PC at office is still windoz xp). I am an avid follower of firefox. But my job includes testing web pages in many browsers. Earlier I was using IE6. But it was a pain to use it as it had no tabs. So after putting it off for many months, finally I decided to have the plunge.

Installing was a pain. If I participated in testing IE8, I will never give OK for it. There are many improvements to be done.
1. Installing process is awfully lengthy. In fact, an OS can be installed within that time.
2. There is no progress bar in the installation dialog, only a scrolling green worm like bar. So you got no idea whether installtion is actually in progress or something has gone wrong and installer is not responding.

Functionality seems still OK. In fact I'm writing the blog, via IE8. :-)

Hats off for Linux

I decided to use Fedora in my Laptop. The biggest hindrence I had to shift to Fedora from Windoz is now solved. You can plug and play USB HSPA modems now. Now hassles, just plug it and it works, even faster than on windoz xp.

This facility is available in Fedora 11 and Ubuntu 9. Guess most of the new Linux like Oss should have this.

C++ with netbeans

Few steps should be followed to integrate C++ with netbeans in Windows

1. Download and install MinGW
2. Download and install msys

• MinGW is the C/C++ compiler
• Msys is some kind of a unix emulator. After installing it and setting it in the path system variable, you can input unix commands such as mkdir, ls in the dos prompt. This is needed as makefile in C++ needs to access unix commands.

3. In the compile command dialog in netbeans provide the MinGW bin directory for base. Then it will identify C and C++ compilers other than the makefile. You need to provide the makefile.exe in msys/bin as the makefile location.

Then as the K&R said in their famouse C book, "if you have not botched anything, it should work" :-)

JSP importing class and jar files

Using java class files in jsp files

1. Put the class files in WEB-INF/classes/ folder

2. Import the class as <%@page import="."%>

3. Call that class as you would do in a normal java program

eg:

<%@page import="test.Hello"%>

<%
Hello heloo = new Hello();
String myName = heloo.SayName();
out.println("From scriptlet : "+ myName + "\n");
%>





Using a jar file in jsp

1. Put the jar file in lib folder.

2. Import the jar file as <%@page import=".*"%>

3. Call the class as .

eg:

<%@page import="jarTest.*"%>

<%
jartest.Main m = new jartest.Main();
String name = m.getName("Pinda");
out.println(name);
%>

Vive la Netbeans

Following day's I was completely worries and frustrated with my bad experience on web services with Eclipse plugging for Axis.

Found a solution today. It is netbeans. Really nice and I love the way it creates the implementation from wsdl file.

axis2 plugins for Eclipse

I wasted a complete day by trying to do a web service using them.

It is a complete bad job. There are no complete set of jar files in lib folder. When the site says it is version 1.4.1 but when downloaded it is shown as 1.3.

Followed 2 tutorials published by WSO2. Oops, only the frustration is left.

When you do something, do it properly.

A simple SOAP client

The program is written in C#.

You can find a java client in http://www.cafeconleche.org/books/xmljava/chapters/ch03s05.html

The below code will not work just by copying and executing. If you are familliar with C# will get the idea.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Xml;
using System.IO;
using System.Net;

namespace WWeb
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
XmlDocument doc = new XmlDocument();

doc.Load(@textBoxIn.Text);

HttpWebRequest req = (HttpWebRequest)WebRequest.Create(textBoxURL.Text);

req.Headers.Add("SOAPAction", "\"\"");

req.ContentType = "text/xml;charset=\"utf-8\"";
req.Accept = "text/xml";
req.Method = "POST";
Stream stm = req.GetRequestStream();
doc.Save(stm);
stm.Close();
WebResponse resp = req.GetResponse();
stm = resp.GetResponseStream();
StreamReader r = new StreamReader(stm);

richTextBox1.AppendText(r.ReadToEnd());


}

private void buttonIn_Click(object sender, EventArgs e)
{
openFileDialog1.ShowDialog();
textBoxIn.Text = openFileDialog1.FileName;
}
}
}

Creating a table from a query

The method varies according to the DB you are using

Oracle:

create table t_newTable as select * from oldTAble;


mySQL:

create table t_newTable select * from oldTAble;


MSAccess:

SELECT * INTO t_newTable FROM oldTAble;

Sample code for accessing mySQL from java

import java.sql.*;


public class DBConnect {

/**
* @param args
*/
public static void main(String[] args) {

Connection connection = null;

try {
String driverName = "com.mysql.jdbc.Driver"; // MySQL MM JDBC driver
Class.forName(driverName);
connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/databaseName", "userName", "password");
}
catch (Exception e) {
e.printStackTrace();
}

Statement stmt;
String s;
String own;

try {
stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM pet");
while (rs.next()) {
// Get the data from the row using the column name
s = rs.getString("name");
own = rs.getString("owner");
System.out.println(s + " owned by " + own);
}
}
catch (SQLException e) {
e.printStackTrace();
}
}

}

My adventures with DB

First step

I was introduced to MS access when I was about 12 years old. To be frank I understand nothing then.

Rebirth

My 2nd introduction to DB was when I was 24 to Oracle. since then I have been studying DBs.

Following is solely my opinion and I do not recommend anyone to follow them. Of course no liability what so ever will be admitted.

MS Access

Our little friend. The best place to get started with DB.

Pros:
1. Intuitive interface
2. Easy imports and exports to other file formats.
3. Easy installation
4. No maintenance

Cons:
1. Poor SQL interface
2. Cannot be used as fully pledged DB server


MySQL
The free guy with lot of talents

Pros:
1. Free
2. Production level DB server
2. Easy to install

Cons:
1. No built GUI


Oracle

Pros:
1. Production level
2. Free version is available

Cons:
1. Messy to maintain.
2. Messy to get started
3. No built in GUI


DB interfaces

DB interfaces add GUI to oracle and mySQL servers

Toad for mySQL

Pros:
1. Free
2. Easy installation
3. Intuitive interface

Cons:
1. One query at a time
2. Importing data from other file formats is bit poor.

Toad for Oracle

Pros:
1. Good functionality
2. Concurrent connections
3. Lot of tools to manage the DB

Cons:
1. Cluttered window. Not even slightly intuitive
2. Free version is a crippled version


SQL developer

Pros:
1. Free
2. Nice object browser
3. Very intuitive interface

Cons:
1. Support only xls and csv file imports

PL/SQL developper

Pros:
1. Intuitive interface

Cons:
1. Lower level support for maintenance

Intergrated light out : HP proliant

HP proliant servers come up with an interesting remote management tool : iLO

The inbuilt one is the basic iLO which is a crippled version of advanced iLO. Basic iLO does not have many feature such as remotely viewing the screen and mounting remote media.

You need to purchase a license for the Advance iLO. As an option you may get a free evaluation licence for 60 days.

One of the disadvantages I observed in iLO is that its screen is not very sensitive. That means it cannot recognize if you move the mouse fast across the screen