Tuesday, February 13, 2007

Monday, January 29, 2007

Dynamic DataSource Routing - Spring 2.0.1

Spring 2.0.1 introduced an AbstractRoutingDataSource. I believe that it deserves attention, since (based on frequent questions from clients) I have a hunch that there are quite a few 'home-grown' solutions to this problem floating around. Mark Fisher posted nice entry about this topic in his blog. Read More.

Pojos In Action - Sample Chapter

POJOs in Action by Chris Richardson -- In this book excerpt from POJOs in Action, Chris Richardson explores the benefits and drawbacks of using the Transaction Script pattern and describes how to implement this pattern using POJOs and the Spring framework

Thursday, January 18, 2007

Hibernate Mapping XML to Oracle XMLTYPE

Oracle XMLTYPE attribute type can be mapped to a W3C Document type representation. Hibernate's UserType mechanism allows to create vendor specific data types. There are certain points to consider when mapping an object to an Oracle XMLType.
Please read more.

Want to try Spring Web Flow ?

SpringFramework announced that Spring Web Flow 1.0.1 was released.

What is Spring WebFlow?
Spring Web Flow is a next generation Java web application controller framework that allows developers to model user actions as high-level modules called flows. The framework delivers improved productivity and testability while providing a strong solution to enforcing navigation rules and managing application state.

Getting Started

The best way to get started with Spring Web Flow is to download the release, read Erwin's practical introduction, and walk through the sample applications. We recommend reviewing all samples, starting with Phonebook, supplementing with reference manual material as needed. Ten sample applications ship with the release, each demonstrating a distinct set of product features.

Spring 2.0 Features - Introduction (Part 1)

Spring 2.0: What's New and Why it Matters is an infoQ article by Rod Johnson, the first of two part. This in-depth piece is well worth reading for anybody wishing to understand the evolution of Spring 2.0 as it introduces significant new features, and how these combine to provide the simplicity and power that is the central theme of this release.

Tuesday, January 09, 2007

ZK - Ajax but no JavaScipt

ZK is an open-source Ajax Web framework that enables rich user interface for Web applications with no JavaScript and little programming.

It has got support for Spring. See the following links for HOW-TO guide.

Contact List with ZK and Spring
- Contact List Project with MySql, Spring and ZK.
ZK with Spring DAO and JDBC - How to setup ZK, Spring DAO and JDBC.

Configuring Single Sign-On using SAML in WebLogic Server 9.2

Configuring Single Sign-On using SAML in WebLogic Server 9.2 by Vikrant Sawant -- In this tutorial Vikrant Sawant shows how to configure SAML on your WebLogic Server domains to enable single sign-on across all deployed Web applications.

Wednesday, December 06, 2006

A Primer on Spring's Data Access Object (DAO) Framework

A Primer on Spring's Data Access Object (DAO) Framework by Dhrubojyoti Kayal -- This article introduces the Spring Data Access Object (DAO) framework. After examining the architectural needs for DAO, it describes the DAO pattern in general and how Spring simplifies the implementation.

Source: Dev2Dev

Wednesday, November 22, 2006

Java - Sorting Algorithms

The animations on this URL illustrate a number of different sequential and parallel sorting algorithms. The relative execution times of the animations give a very rough idea of the relative speeds of the algorithms. Each algorithm is finished when its colored lines disappear.

To see animation, you need Java Runtime Enviroment.

How Oracle Hash Join works?

Hash Join is one of join used by Oracle server when we joine multiple table. Following link will give you a demo on Flash. This demo explains how Hash Join works in Oracle.
This demo was created by TomKyte from Oracle. I got this link from AskTom.

http://tinyurl.com/l2qsh

Alternatively, if you want "offline viewing" of this, you can download a .exe
file (about 1.8mb) that lets you play this whenever you want:

http://tinyurl.com/nyjro

Monday, November 20, 2006

Nagios

Nagios is a host and service monitor designed to inform you of network problems before your clients, end-users or managers do. It has been designed to run under the Linux operating system, but works fine under most *NIX variants as well. The monitoring daemon runs intermittent checks on hosts and services you specify using external "plugins" which return status information to Nagios. When problems are encountered, the daemon can send notifications out to administrative contacts in a variety of different ways (email, instant message, SMS, etc.). Current status information, historical logs, and reports can all be accessed via a web browser.

Nagios is licensed under the terms of the GNU General Public License Version 2 as published by the Free Software Foundation. This gives you legal permission to copy, distribute and/or modify Nagios under certain conditions. Read the 'LICENSE' file in the Nagios distribution or read the online version of the license for more details. Nagios is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE WARRANTY OF DESIGN, MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE.

Friday, November 10, 2006

VPN Solution - Hamachi , OpenVPN

Hamachi is a great program that enables you to easily set up an encrypted private network between remote computers over the open internet. It's a simple elegant solution without much fuss. It does have some limitations, but it's definitely an easy and secure way to access your shared folders, enable remote network gaming, and control your machines via Remote Desktop or VNC type programs.

Nice tutorial, how to setup Hamachi is available here.

OpenVPN is a full-featured SSL VPN which implements OSI layer 2 or 3 secure network extension using the industry standard SSL/TLS protocol, supports flexible client authentication methods based on certificates, smart cards, and/or username/password credentials, and allows user or group-specific access control policies using firewall rules applied to the VPN virtual interface. OpenVPN is not a web application proxy and does not operate through a web browser.

Oracle Tip - SQL Order by clause with CASE

How to use CASE in ORDER BY clause of SELECT statement in Oracle SQL.
Order By clause allow you display data in ASCENDING or DESCENDING.

Using Order By clause we can able to arrange data in ASCENDING or DESCENDING based on columns. If it is VARCHAR2 column for ASCENDIGN and DESCENDING data will be sorted by Alphabetical. What if we want to sort CUSTOM Sort, not Alphabetically ascending or descending.

For example, take the following SQL. We can display CITY column either in Alphabetically ASC or DESC.

SQL with ORDER BY CITY ASC:
===========================

select city from (
select
'San Francisco' a from dual
union all
Select 'Boston' a from dual
union all
Select 'Charlotte' a from dual
union all
Select 'Phoenix' a from dual
union all
Select 'Houston' a from dual
union all
Select 'Washington DC' a from dual)
order by city ASC

Now let us see how we can do Custom Sorting using CASE clause in ORDER BY Clause.
We want to get list of city in the follwoing order, then we will use the following SQL.

CITY
=====
Charlotte
Boston
Phoenix
Washington DC
Houston
San Francisco


SQL with CUSTOM Sorting.
========================

select city from (
select
'San Francisco' a from dual
union all
Select 'Boston' a from dual
union all
Select 'Charlotte' a from dual
union all
Select 'Phoenix' a from dual
union all
Select 'Houston' a from dual
union all
Select 'Washington DC' a from dual)
order by CASE a when 'Charlotte' then 1
when 'Boston' then 2
when 'Phoenix' then 3
when 'Washington DC' then 4
when 'Houston' then 5
end;


Please note that in CASE clause, I never mentioned about 'San Francisco' city. But the SQL will bring 'San Francisco' as last city in the record set.

This may be required sometimes, we want to display in DropDown List box in frontend applications.

Wednesday, November 01, 2006

Oracle - Jonathan Lewis blog

Jonathan Lewis started blogging since last week. I need to track his blog every day.

Nice blog for Oracle tips

Monday, October 30, 2006

Sample build.xml for Tomcat & JBoss

I have spend lot of time to figure out sample build.xml sample files to deploy Struts Application as WebApplication to Tomcat server. Finally I found out from Developer Apple website.

Here is link for Tomcat Struts build.xml as WAR file.

Another link for build.xml to deploy Struts application to JBoss server as EAR file.

Tuesday, October 24, 2006

Using Oracle's recycle bin - Oracle 10G feature

In OraFaq, Using Oracle's recycle bin was posted by Natalka Roshak. This article gives very nice examples to demonstrate this feature in simple manner.

Natalka Roshak scripts and tips can be found in her online DBA toolkit at http://toolkit.rdbms-insight.com/.

Monday, October 23, 2006

what is VTD-XML

Simplify XML processing with VTD-XML
A new option that overcomes the problems of DOM and SAX

Cut, paste, split, and assemble XML documents with VTD-XML

VTD-XML eliminates the performance overhead associated with updating XML

Monday, October 09, 2006