Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > Java > what the java virtual machine truely is?

Reply
Thread Tools

what the java virtual machine truely is?

 
 
525
Guest
Posts: n/a
 
      03-06-2008
Q: Can the java code run without java virtual machine ? When we
instal the jdk, does the java virtual machine setup at the same
time? What is the relationship between the fold jre and java
virtual machine ?
 
Reply With Quote
 
 
 
 
Lew
Guest
Posts: n/a
 
      03-06-2008
525 wrote:
> Q: Can the java [sic] code run without java virtual machine ?


Normally, no, but there are some compilers like GCJ (Gnu Compiler for J*va)
that can run some Java code without a JVM.

> When we instal the jdk [sic], does the java virtual machine setup at the same
> time?


It installs at the same time, in the form of the "java" command (java.exe on
Windows), so I guess you could say its set up at the same time. There
wouldn't be much point to the JDK without the JVM, after all.

But simply installing the JDK doesn't *run* the JVM. That happens when you
(directly or indirectly) invoke the 'java' command.

> What is the relationship between the fold jre and java virtual machine ?


What do you mean by the "fold" JRE?

The JRE comprises the Java Virtual Machine and the rest of the Java Runtime
Environment, including various bootstrap JARs and other components.

Java, the programming language, is spelled with a capital "J".

--
Lew
 
Reply With Quote
 
 
 
 
Mike Schilling
Guest
Posts: n/a
 
      03-06-2008
Lew wrote:
> 525 wrote:
>> Q: Can the java [sic] code run without java virtual machine ?

>
> Normally, no, but there are some compilers like GCJ (Gnu Compiler
> for
> J*va) that can run some Java code without a JVM.
>
>> When we instal the jdk [sic], does the java virtual machine setup
>> at
>> the same time?

>
> It installs at the same time, in the form of the "java" command
> (java.exe on Windows), so I guess you could say its set up at the
> same time. There wouldn't be much point to the JDK without the JVM,
> after all.
> But simply installing the JDK doesn't *run* the JVM. That happens
> when you (directly or indirectly) invoke the 'java' command.
>
>> What is the relationship between the fold jre and java virtual
>> machine ?

>
> What do you mean by the "fold" JRE?


I'm guessing it's a typo for "full" (possibly assisted by a
spell-checker that converted, say, "fuld" to "fold").

>
> The JRE comprises the Java Virtual Machine and the rest of the Java
> Runtime Environment, including various bootstrap JARs and other
> components.
> Java, the programming language, is spelled with a capital "J".



 
Reply With Quote
 
Sabine Dinis Blochberger
Guest
Posts: n/a
 
      03-06-2008
Mike Schilling wrote:

> Lew wrote:
> > 525 wrote:
> >
> >> What is the relationship between the fold jre and java virtual
> >> machine ?

> >
> > What do you mean by the "fold" JRE?

>
> I'm guessing it's a typo for "full" (possibly assisted by a
> spell-checker that converted, say, "fuld" to "fold").
>
> >

I thought he meant "folder". Either of the possibilties make sense to me

--
Sabine Dinis Blochberger

Op3racional
www.op3racional.eu
 
Reply With Quote
 
Roedy Green
Guest
Posts: n/a
 
      03-06-2008
On Wed, 5 Mar 2008 20:56:38 -0800 (PST), 525
<(E-Mail Removed)> wrote, quoted or indirectly quoted someone
who said :

>Q: Can the java code run without java virtual machine ?

That's a matter of semantics. It is possible to compile to native
code. The vm is there only in the vaguest sense. see
http://mindprod.com/jgloss/nativecompiler.html

>When we
>instal the jdk, does the java virtual machine setup at the same
>time?


The vm only exists while Java.exe is running.

>What is the relationship between the fold jre and java
>virtual machine ?


When the JRE java.exe is running it is simulating the Java virtual
machine. In other words, it makes your computer pretend to be an
ideal Java computer that can run class files directly.


--

Roedy Green Canadian Mind Products
The Java Glossary
http://mindprod.com
 
Reply With Quote
 
Arne Vajhøj
Guest
Posts: n/a
 
      03-08-2008
Lew wrote:
> 525 wrote:
>> When we instal the jdk [sic], does the java virtual machine setup at
>> the same
>> time?

>
> It installs at the same time, in the form of the "java" command
> (java.exe on Windows), so I guess you could say its set up at the same
> time. There wouldn't be much point to the JDK without the JVM, after all.


Especially not since much (possible most) of the functionality in JDK
is implemented in Java (tools.jar).

Arne
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to verify if an employee truely has an MCSE =?Utf-8?B?Qm9kaW5lOTU=?= Microsoft Certification 8 01-15-2010 06:52 AM
At least we truely now know who to ultimately blame for the prolonged HDDVD/blu ray war! GMAN DVD Video 3 02-26-2008 07:45 PM
Force java applet to run on java microsoft virtual machine plugin and not Sun. emaxt6@yahoo.com Java 4 05-09-2005 03:54 PM
return truely random number? sam Perl Misc 3 12-25-2004 08:19 PM



Advertisments