3d css with perspective and transform rotate

The perspective CSS property gives an element a 3D-space by affecting the distance between the Z plane and the user. The strength of the effect is determined by the value. The smaller the value, the closer you get from the Z plane and the more impressive the visual effect. The greater the value, the more…

java generic multi-level wild card

Was having a interesting issue on Generic which i thought i was pretty familiar with. Basically i need to pass a Map<String, List<SubClass>()> to a Map<String, List<SuperClass>()> I was thinking i could just do Map<String, List<? extends SuperClass>()> in the method signature, then i should be fine. But i get compiler error complaining type not…

singleton Double-Checked-Locking AND Initialization-on-demand

Double-Checked Locking is widely cited and used as an efficient method for implementing lazy initialization in a multithreaded environment. Unfortunately, it will not work reliably in a platform independent way when implemented in Java, without additional synchronization. When implemented in other languages, such as C++, it depends on the memory model of the processor, the…

hive jdbc with Spring Beanpropertyrowmapper

In our project we need to port some hive table data to our local RDBMS(Oracle). For tables with a lot of columns(hundreds), it could be very tedious to wrote the hive sql and convert the resultSet to the Jpa entity object. Spring jdbctemplate provides us a good class which would do camel-case conversion to the underscore for us….