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jdk, sdk, jre...

Daniela Ch
Ranch Hand

Joined: Dec 13, 2002
Posts: 96
Can anyone clarify what are the differences between jdk, sdk and jre?
I am doing an assignment and in the specification they state that :

The submission that you return must have been tested and shown to work under a production (not development) version of the Sun Microsystems' Java 2 platform.

What is the difference between a production and a development version, and between a sdk, a jdk and a jre...
I had to installed those two executable (please dont ask me what they are I dunno...)
How to know if they are a production version? They also ask for the jdk version but wich one is the jdk?
Avi Abrami
Ranch Hand

Joined: Oct 11, 2000
Posts: 1141

Hi Daniela,
JRE = Java Runtime Environment
JDK = Java Development Kit
SDK = Software Develoment Kit
(So much for the TLAs ;-)
The JRE is what you need in order to execute compiled java classes (otherwise known as java byte codes). It consists of the "java" executable and JAR files containing the compiled classes of the core java library (like "java.lang.String").
The JDK is the previous name for what is now known as the J2SE SDK -- Java 2 Standard Edition Software Development Kit -- so SDK and JDK usually mean the same thing. The JDK is a superset of the JRE -- it contains all of the JRE plus some extra tools/utilities (like the java compiler "javac").
So if you only want to execute java applications, you only need the JRE, but if you want to develop java applications, then you (only) need the JDK (since it includes the JRE).
As regards the difference between production and development versions, I'm not sure if I understand the question correctly, but I'll answer it according to how I interpret it. The SUN Microsystems company releases versions of the JDK (and JRE). Ususally they release what they call a "beta" version -- one that they would like the community of java programmers in the world to try out (or test) for them. They know that there will most probably be bugs in the "beta" version that members of the java community will discover. The "beta" version of the current JDK (1.4) was in circulation for about one year (I think) before SUN released the "production" version.
The production version is meant to be "stable" and (relatively) bug free.
So the idea is that they (SUN) release a "development" version, then they fix the bugs that are discovered and then they release the same version (with the bugs fixed) and call it a "production" version.
Hope this has helped you.
Good Luck,
Daniela Ch
Ranch Hand

Joined: Dec 13, 2002
Posts: 96
Aahh...I understand...
thanks Avi for clearing things up...
Daniela Ch
Ranch Hand

Joined: Dec 13, 2002
Posts: 96
thanx again
I agree. Here's the link:
subject: jdk, sdk, jre...
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