In the existing projects where I'm working I see that there are Java EE jars like j2ee-1.3.jar existing, but when I try to download from Oracle website (1.6 version) I only see .exe available. So how are they connected, is it like exe after installation will create jar in the installation folder?
I checked the contents of exe with WinRAR but could not find any jar.
Also I have the same question regarding exe of JRE and adding it as external jar to eclipse project.
.jar is a library /package of Java and when you are on oracle to download it's application of java i.e. jdk or jre.
So when we do programming jars are used to add functionality, we will have to import classes from it.
when we want to use external classes then we have to use it's jar file.
when we do any import like import org.springframework.beans.factory.annotation.Autowired; it came from jar or dependency.
You can make executable jar file of java program, you can find out tutorial for it online. so whenever you click on that executable jar file in any machine where jre is installed you can access it. This is called Executable Jar, and you are telling about Java EE exe is setup application for New Fresh Java Installation.
I suppose you are talking about the JDK installation executable file... So yes you guessed part of the answer, the JDK installation file for windows systems is an executable file that will do nothing but downloading and unpacking the JDK/JRE which is a set of java libraries jars (which you use for your development) in some directories you specify in installation steps.
This is the mains ubject of you question, but note that you will not only find jars when browsing the JDK installation directory, but a lot od other bunch, mains to be cited:
java process uses for runnig your application.javac binary file used for code compilation... and many other staff