Ujjwal's Blog: December 2010

Thursday, December 30, 2010

Shell script for clearing the Trash in Ubuntu linux

Hi,

I was facing a problem while clearing the Trash in Ubuntu Linux. I wasn’t able to delete certaion folder and i got the message stating “Access Denied”. So i was wondering that there should be some way to do it from the command prompt using sudo and some command. I did a google for the requirement and found the following shell snippet:

rm -rf ~/.local/share/Trash/

Regards,

Ujjwal Soni

Intresting tool for eclipse

Hi,

Here's an intesting tool i found on web that can help eclipse users to autogenerate and spice up their java code. This sort of tool is already built into myeclipse, but if you use eclipse, then this tool can work out towards great help.

Here's the URL : http://projectlombok.org/index.html

Regards,

Ujjwal Soni

Happy Coding

Friday, December 24, 2010

Merry Christmas

Hello Everyone,

Merry Christmas & Happy new year....

Cheers,

Ujjwal Soni

Saturday, December 18, 2010

hibernate vs jdbc response time

Hi,

Last week i received an email from one of my blog reader, he wanted to know response times for hibernate and jdbc. So below are my views on that ::

Hibernate is just a little slower than JDBC. Actually, We don't use Hibernate in very small applications or when "Persistence" is not at all an issue.

Requirement decides the use of Hibernate.

In modern multi tire applications we need such features.

JDBC is a traditional way of connecting... Hibernate is ORM based. It sees all the tables as an object so that we can optimally utilize and finetune the performance. Only thing u need to take care is the DB design. Once if the DB design is done (perfectly), i can say hibernate would be much better than JDBC.

Another advantage is that Hibernate can take an object itself as a parameter and gives room to use the Java Collections.

So, in short, if you have a small application then implementing hibernate is a bad idea.

Cheers,

Ujjwal Soni,

ForwardAction, IncludeAction and LocaleAction in struts

The org.apache.struts.actions.ForwardAction Class
The ForwardAction class provides a mechanism for forwarding 
to a specified URL. As explained earlier, in an MVC Web 
application, all requests to the application are supposed 
to flow through the Controller servlet. This ensures that 
the Controller layer of the application has an opportunity 
to prepare any resources that may be needed to handle the 
request (i.e., selecting the correct module and so on). 
ForwardAction is provided as a simple utility action that 
can be used for scenarios in which you simply want to link 
to a JSP page. Of course, linking directly to the JSP would 
be a violation of the MVC principles because all requests 
are supposed to be routed through the Controller. 
ForwardAction can be used to create links to JSPs so that 
you don’t have to create an action whose only 
responsibility is to forward a request every time you want 
to link to a JSP. With ForwardAction, you simply create an 
action mapping in the Struts configuration file and specify 
the location to which the action will forward.

To use ForwardAction, simply create action mapping entries 
in the Struts configuration file, as shown next:


  


Once configured in the Struts configuration file, 
LocaleAction can be put to use. Simply create a link to the 
action and specify the locale settings that will be set and 
a page to forward to. Locale settings are specified with 
two request parameters: language and country. The page to 
forward to after setting the locale is specified with the 
page request parameter. The following URL illustrates how 
to use the request parameters:

http://localhost:8080/MiniHR/SwitchLocale.do?
country=MX&language=es&page=/Menu.do 

This example URL sets the country to MX and the language to 
es. The /Menu.do page will be forwarded to after the new 
locale has been set.

Cheers,

Happy Coding :-)

difference. between. update() and merge() in hibernate

Hi,

Here's the difference. between. update() and merge() in hibernate

Update():- if you are sure that the session does not contains an already persistent instance with the same identifier then use update to save the data in hibernate

Merge():-if you want to save your modificatiions at any time with out knowing abot the state of an session then use merge() in hibernate.

Cheers,

Happy Coding :)