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 …
Permanent link to this article: http://www.javaplex.com/blog/java-sorting-objects-at-runtime-using-comparator/
Jan
26
Hibernate Enum Datatype Mapping
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 …
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Jan
17
Hibernate persist() vs. save()
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, …
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Nov
25
For JSF 2.0, How to Enable EL 2.2 on Tomcat 6
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, …
Permanent link to this article: http://www.javaplex.com/blog/for-jsf-2-how-to-enable-el-2-2-on-tomcat-6/
Nov
24
Generic DAO with Hibernate and Spring
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 …
Permanent link to this article: http://www.javaplex.com/blog/generic-dao-with-hibernate-and-spring/
Nov
22
Spring Caching with Simple-Spring-Memcached (SSM)
Simple Spring Memcached (http://www NULL.slideshare NULL.net/nelz9999/simple-spring-memcached)
Permanent link to this article: http://www.javaplex.com/blog/spring-caching-with-simple-spring-memcached-ssm/
Nov
20
How to achieve Database Auto ID Generation Portability in Hibernate
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 …
Permanent link to this article: http://www.javaplex.com/blog/how-to-achieve-database-auto-id-generation-portability-in-hibernate/
Nov
17
MyEclipse Customizing Hibernate Reverse Engineering
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 …
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Nov
03
Myfaces 2 Exception: could not find Factory: javax.faces.application.ApplicationFactory
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 …
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Oct
10
Eclipse Error: A cycle was detected in the build path
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 …
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