May, 2013 - Post

Groovy - Getting Started

This article help you start with Groovy, with step by step guide and series of examples. It starts with an overview and then covers in detail examples. Groovy Overview Groovy is an Object Oriented Scripting Language which provides Dynamic, Easy-to-use and Integration capabilities to the Java Virtual Machine. It absorbs most of the syntax from Java and it is much powerful in terms of functionalities which is manifested in the form Closures, Dynamic Typing, Builders etc.

May, 2013 - Post

Scala - Getting Started - Part 2

In previous article we learned basics of Scala, in this articles we will learn how to setup build scripts for scala and build applications using scala. We will also learn few web development frameworks for Scala and compare them with similar framework in Java. Building Scala Applications Below program demonstrates the use of Scala script with Maven, Ant, and logging library – LogBack. Integration with Ant Below example shows how Scala project can be built by the ant build.

May, 2013 - Post

Scala - Getting Started - Part 1

This article help you to start with Scala, with step by step guide and series of examples. It starts with an overview and then covers in detail examples. In later articles, I will write about feature comparison with other languages. It article is helpful for people coming from Java background, how it is not the prerequisites. Scala Overview Scala is a general purpose programming language designed to express common programming patterns in a concise, elegant, and type-safe way.

Feb, 2013 - Post

Charset configuration in JVM

This article describes how to configure charset for a JVM. We faced an issue on a Linux environment, a file containing some Swedish character was not being read correctly by underlying JVM since the default charset of JVM was picked as UTF-8 (which does not support some Swedish character). But on the other hand, in Windows environment, it was working fine since the default charset was picked as Windows-1252 (which does support these characters).

Sep, 2012 - Post

Working with Embedded OLE Objects in Java

Document introduction contains a proof of concept for the research done on reading and writing OLE objects in Java. This research has been done using Apache POI. Please go thru the references for information about apache POI. This article covers a POC to fetch OLE objects from RIF formatted XML. Not just that, we need to store them in a in some viewable format. For a given XML in RIF format, parse it and read the embedded OLE object and represent in some viewable format using Java.

May, 2012 - Post

JavaScript Plugin Framework

Javascript Plugin Framework is implemented to add extra functionality in the existing Web based application without actually changing the application code. This framework is also helpful when some functionality need to control for different user profiles. For example, to add one extra button in a menu we can write the plugin directly, by defining what that button is going to do on click, what all events should it handle, in one javascript file rather than making changes in the application code for the same.

May, 2012 - Post

Strange JSP Compilation Issue

We were getting following error on the production sever (Linux, Jboss). We were in the middle of user acceptance testing with the client, many users were accessing the application to simulate various scenarios in a live session. the application was crashing just after 2-3 minute of start with above error, and no user were able to access the application. We were expected for fix the issue ASAP, as the users were assembled for the web session, all were waiting for the server up.

Apr, 2012 - Post

Default Timezone in Java and MySQL

On one of our production environments, we had an issue our application related to time, specially modified time and creation time of the entities. It was quite random in nature for some entities. We suspected that there might be issue in the timezone configuration. Analysing the problem On production environment, we had limited permissions. We were not allowed to change system timezone. We noticed that Jboss is automatically picking the system timezone “Europe/Berlin” (which was configured from root user) and if we check the timezone for the linux user for which we have access it shows GMT time.

Mar, 2012 - Post

MySQL Tuning

We have faced ‘out of space’ issue on disk even after clearing old data on database server(MySQL) and temporary data on application. We noticed that 90% of the space was occupied by the database tables which were used to store very large de-normalized statistical data and when we track the database table we noticed there is not much data in the database in the tables but they were still occupying space on disk.

Mar, 2012 - Post

Rule Engine - Getting Started with Drools

This article let you start with Rule Engine Drools, with step by step guide and series of examples. It starts with an overview and then covers in detail examples. Rule Engine Overview The underlying idea of a rule engine is to externalize the business or application logic. A rule engine can be viewed as a sophisticated interpreter of if-then statements. The if-then statements are the rules. A rule is composed of two parts, a condition and an action: When the condition is met, the action is executed.

Feb, 2012 - Post

Compiling Java Native C/C++ Code

We have faced multiple issues while compiling a native c/c++ code and using it with JNI in our Java application How to write a JNI program. jni_md.h not found. Incompatible data types. On widows cygwin1.dll is required when running Java code on the native library. and more. Actually we were compiling NLP Solver’s native library (IPOPT) on windows 32 bit and on 64bit linux machine. Solving the chaos! Here are the steps we have followed to solve the above issues:

Jan, 2012 - Post

Using Apache CFX and Apache Camel in ESB

In the previous article, we learned about ESB and deployed our first OSGi bundle on FuseESB. In this article, we will learn how to build Apache CXF and Apache Camel component and deploy them on FuseESB. Lets understand what are these components : Apache Camel ™ Powerful open source integration framework based on known Enterprise Integration Patterns with powerful Bean Integration. Camel lets you create the Enterprise Integration Patterns to implement routing and mediation rules in either a Java based Domain Specific Language (or Fluent API), via Spring or Blueprint based Xml Configuration files or via the Scala DSL.

Jan, 2012 - Post

Managing Calendar and Invites in Java

Calendars are used to store formation for various events. Calendar viewer displays the month-date view and for each day displays the events/reminders information. Invites are the events in the form of email. Once the invite for an event sent to a user via email then that event will be stored in the calendar view and same can be seen in the day information of the calendar view. Calendars Calendar data can be stored in files; there are some standard formats for storing calendars iCalendar is a computer file format which allows Internet users to send meeting requests and tasks to other Internet users, via email, or sharing files with an extension of .

Jan, 2012 - Post

Working with Enterprise Service Bus

This article starts from basic terms of ESB worlds and then provides details of the FuseESB with various examples. It contains step by step guide to install FuseESB, and develop and deploy OSGi bundle on FuseESB. Lets understand terminologies of the ESB world : ESB An Enterprise Service Bus (ESB) is a software architecture model used for designing and implementing the interaction and communication between mutually interacting software applications in Service Oriented Architecture.

Jan, 2012 - Post

Mail Merge in Java

MailMerge is a process to create personalized letters and pre-addressed envelopes or mailing labels for mass mailings from a word processing document (Template). A template contains placeholders (Fields) along with the actual content. The placeholders are filled by the data source which is typically a spreadsheet or a database having column for each place holders. This article talks about the java approach for generating multiple documents from a single MS Word template.

Jan, 2012 - Post

Font configuration in JVM

Last year we have migrated one of our application from Java 5 to Java 6. The Java 6(OpenJDK) installation was done by client on a fresh system. After installing our application (under JBoss app), we found the fonts on JFreeCharts and on the images generated from AWT were not correct. We have solved the issue by configuring the fonts at JVM level. Let understand it better. How AWT / JFreeCharts shows the fonts AWT rely on native fonts, it usages default Java fonts (which best fits) if no native fonts mapping found.