Java program to execute shell scripts on remote server

If you want to execute shell scripts on remote server and get output with the help of your java program then you are at right place. In this tutorial we will be using Java secure channel ( Jsch ) to log on to remote server, execute the shell script and capture the output. JSch is a pure Java implementation of SSH2. ( download jSch ).

Call a method just before a session expires

In this tutorial we gonna learn that how to call a specific method when a session is going to be destroyed or invalidated by the application container. First of all we need to know why we are doing this. Well it may have many applications but typically we use it for updating user counts, releasing resources etc. We could use HttpSessionListener and do the job in sessionDestroyed() method.

Life cycle of the servlet

A servlet is a Java programming language class that is used to extend the capabilities of servers that host applications accessed by means of a request-response programming model. Although servlets can respond to any type of request, they are commonly used to extend the applications hosted by web servers. ( more reference ).

How to detect width of text inside text box

In this tutorial we are going to see how to calculate the width of text inside the text box. First of all we need to know why we are trying to achieve this. This is useful when you want to position some text suggestion just beneath the user cursor inside the text box. The image given below will provide better understanding of the scenario.

Enable gzip compression in apache

When a user types your website url in browser and hits enter, browser sends request to server. Server responds to that request in the form of reply by giving back the requested document. That document can be of any size, typically if we take javascript files, it can be between 100 to 200 KB. Is there is any way to reduce this size so that the downloading can be faster ? Answer is "yes", that's what gzip compression does. It compresses the document size to almost 70% of the original. The major benefit of gzip compression is that it reduces bandwith by reducing the size of the response from the server.

Merchant guide to galaxy

Thoughtworks interview question

You decided to give up on earth after the latest financial collapse left 99.99% of the earth's population with 0.01% of the wealth. Luckily, with the scant sum of money that is left in your account, you are able to afford to rent a spaceship, leave earth, and fly all over the galaxy to sell common metals and dirt (which apparently is worth a lot).Buying and selling over the galaxy requires you to convert numbers and units, and you decided to write a program to help you.The numbers used for intergalactic transactions follows similar convention to the roman numerals and you have painstakingly collected the appropriate translation between them.Roman numerals are based on seven symbols.