what the java virtual machine truely is?

[525]

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 ?

 

[Lew]

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".

 

[Mike Schilling]

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").

 

[Sabine Dinis Blochberger]

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

 

[Roedy Green]

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.

 

[Arne Vajhøj]

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