is functionality in jdkvx and javase ver.x the same?

hello,

does the jdk version follow closely java se functionailty, in particular jdk7 following jave se7 and jdk6 functonaity following java se6 functionality?

my question is with regards to the oracle tutorials,w here there are references to functionality in java se7 and jdk7

"New in the Java SE 7 release, the fork/join framework is an implementation of the ExecutorServiceinterface that helps you take advantage of multiple processors. It is designed for work that can be broken into smaller pieces recursively."

"In JDK 7, java.util.concurrent includes a convenience class, ThreadLocalRandom,"

i want to stick to JDK6/Java se6, not sure if jdk and java se are synonymous?

Java SE is the runtime environment - its what runs the application you write. JDK is the development kit, it allows you to write the code itself and compile it. The JDK and Java SE (JVM or JRE) versions do correspond. Anything written in JDK 1.6.x and compiled for JRE 1.6.x will run on JRE 1.6.x or newer.

Java 1.7 isn't out yet, I would stick to java 1.6 stuff. Anything that is tagged 1.7 specific probably wont work on 99.9% of peoples machines unless they have the 1.7 beta installed. 1.6 is quite robust and should do everything you need!

thanks for the reply,

so there is a correspondence in the sense that anything that is written in jdk 1.6.x is not guaranteed to run on JRE1.5.x, correct?

If it is compiled specifically for 1.6 then it will require 1.6. However, you can use 1.6 and target any older version - 1.5, 1.4.2, etc... You're just limited in the code features you use.

So if you are running 1.6 and only use 1.4.2 features, and target 1.4.2 at compile time, then you can create a program that runs on everything from 1.4.2 and newer.

At this point, 1.6 has been around for so long, I think you're safe in targeting 1.6 unless you have the need to work with some really legacy stuff.