Java Questions

Type 4  (JDBC Net pure Java Driver) is the fastest JDBC driver.  Type 1 and Type 3 drivers will be slower than Type 2 drivers (the database calls are make at least three translations versus two), and Type 4 drivers are the fastest (only one translation).

The Spring Beans are Java Objects that form the backbone of a Spring application. They are instantiated, assembled, and managed by the Spring IoC container. These beans are created with the configuration metadata that is supplied to the container.
Beans defined in spring framework are singleton beans. There is an attribute in bean tag named "singleton" if specified true then bean becomes singleton and if set to false then the bean becomes a prototype bean. By default it is set to true. So, all the beans in spring framework are by default singleton beans.

JDK is Java Development Kit which is for development purpose and it includes execution environment also.

JVM is Java Virtual Machine which is a run time environment for the compiled java class files .Hence you will not be able to compile your source files using a JVM.

It can either be Final or Abstract

The purpose of garbage collection is to identify and discard those objects that are no longer needed by the application, in order for the resources to be reclaimed and reused.