JDK, SDK, JDT, JRE, what is all stuff? why do i need it?

[sonny]

i'm suffering from a google information overload!
half way through a tutorial, it starts going on about the project properties and attaching sources to things. importing JARs and all sorts of stuff.
some i kinda follow some of it i'll get to grips with, with practice i'm sure.

But, I dont have a JDK installed. (or maybe its not where it should be)
after a bit of googling i am a bit confused as to which flavour of JDK i need.
theres a few with all kinds of letters like EE, FX, SE and others

obviously I have the JRE installed, i Know I need that.
will i need to uninstall that before i install the JDK?

I have something in eclipse called the JDT or is it SDK or is it both, i'm not too sure but, I am half Guessing from google that the JDK is some sort of extension of that.

some simple clarification would be useful to me. Do I really need it, and if so which flavour do I need??

thanks in advance,

[gcalvin]

You have Eclipse, so you do have a JDK. It may not be on your PATH, though. What happens when you type javac -version at a command prompt?

-Gary-

[gcalvin]

By the way, JDK is simply Java Development Kit. It's the tools for compiling Java programs, and also for making JAR files. It's separate from the JRE (Java Runtime Environment) because people who just want to run Java programs, but don't want to write them, don't need the JDK.

SE is Standard Edition and EE is Enterprise Edition. If you don't know why you need EE, then you don't need it, but it won't hurt you if it's there (EE is a superset of SE). EE is bigger and has more stuff.

-Gary-

[sonny]

from C:\ i get
" 'javac' is not recognised as an internal or external command, operable program or batch file "

a file search for javac brings up four strange loooking files
all called javaCompletionProposalSorters.exsd

[gcalvin]

How about that? Apparently, Eclipse uses its own built-in compiler code, and doesn't depend on a JDK. Makes sense when you think about it, considering how editing, syntax checking and debugging are so tightly integrated, but I never thought about it before. My MacBook has always had a JDK.

Anyway, just get the Java SE JDK.

Java SE Downloads - Sun Developer Network (SDN)

That's plenty until you know you need more, and why.

-Gary-

[gcalvin]

And if you're still curious about JDT, check this out:

JDT Core Component

-Gary-

[sonny]

thanks Gary