Java Plex by Java Developers » Programming

Simple CSV Generator

admin — Sun, 29 Jan 2012 20:37:50 +0000

I want to share a very simple example which can be used to generate CSV in Java. The code is self explanatory and easy to understand.

Java Sorting Objects at Runtime using Comparator

Faisal Basra — Thu, 26 Jan 2012 06:11:18 +0000

Java gives very convenient way for sorting collection types by Collections.sort method. It have two flavors Collections.sort( collection, new Comparator < T>( )){} This is runtime sorting, & you will create an anonymous class implementation and will override Comparator’s compare method and return value -1, 0 , 1. Collections.sort( collection) You provide collection whose objects implemented Comparable or Comparator interface …

Hibernate Enum Datatype Mapping

Faisal Basra — Thu, 26 Jan 2012 05:14:30 +0000

If you want to map a enum in JPA/Hibernate POJO class, so that only specific values can be saved for underlying database column, it is possible now very easily. The sample POJO File is given below, have an idea. @Enumerated( javax.persistence.EnumType.STRING ) tells what values you want into database from provided enum type, & hibernate will …

Hibernate persist() vs. save()

admin — Tue, 17 Jan 2012 07:50:34 +0000

In case anybody finds this thread… For persist() The semantics of this method are defined by JSR-220. persist() is well defined. It makes a transient instance persistent. However, it doesn’t guarantee that the identifier value will be assigned to the persistent instance immediately, the assignment might happen at flush time. The spec doesn’t say that, …

For JSF 2.0, How to Enable EL 2.2 on Tomcat 6

Faisal Basra — Fri, 25 Nov 2011 10:33:03 +0000

How to Enable EL 2 for Java Server Faces 2.x on server running older EL version EXCEPTION: com.sun.faces.config.ConfigurationException: It appears the JSP version of the container is older than 2.1 and unable to locate the EL RI expression factory, com.sun.el.ExpressionFactoryImpl. If not using JSP or the EL RI, make sure the context initialization parameter, com.sun.faces.expressionFactory, …

Generic DAO with Hibernate and Spring

Faisal Basra — Thu, 24 Nov 2011 12:29:55 +0000

If you are using Hibernate with Spring, then you will be dealing with huge set of DAOs. In such case best way to minimize the DAO work with Generic DAO patter, which encapsulate CRUD + basic finder method and then write only very required methods. I’m inspired by the IBM Generic DAO pattern and rewrite …

How to achieve Database Auto ID Generation Portability in Hibernate

Faisal Basra — Sun, 20 Nov 2011 10:25:03 +0000

Hibernate meant to be Database independent ORM solution, but while migrating to another database vendor some key issues arrives. One of them is Auto ID generation of underlying database. MySQL, Oracle & MS SQL Server all uses different techniques to generate auto ID for primary keys. So, when we start migrating we face lot of …

MyEclipse Customizing Hibernate Reverse Engineering

Faisal Basra — Thu, 17 Nov 2011 05:27:27 +0000

Most of the time you want to perform hibernate reverse engineering to generate Pojos from underlying database using hibernate-tools or directly from My Eclipse which also uses hibernate-tools. But some times we want to control the mechanism by which hibernate tools generate pojos, like we want to have prefix or suffix in our class name …

Myfaces 2 Exception: could not find Factory: javax.faces.application.ApplicationFactory

Faisal Basra — Thu, 03 Nov 2011 06:24:34 +0000

Myfaces Exception: could not find Factory: javax.faces.application.ApplicationFactory This exception comes when you have Mojara jars on your server/tomcat etc and your are shipping MyFaces with your application, this will eventually comes out. So try to delete the Mojara from class path. Another problem while developing with MyEclipse, if you create a web project and set …

Eclipse Error: A cycle was detected in the build path

Faisal Basra — Mon, 10 Oct 2011 06:25:15 +0000

We were just facing very tedious error by eclipse “A cycle was detected in the build path” and it take some time what the problem was. Actually we You can instruct the Eclipse to ignore this error. Follow the instructions at. Preferences > Java > Compiler > Building > Build path problems > Circular dependencies …