running duel JDKs on XP

[frank]

If this is not the correct forum for this question please let me know
which one as I looked and did not see a better one.

I need to run 2 version of java JVM/JDKs , 1.4.x and 1.5 on the same XP
machine but have different programs running using the different JVMs/JDK
compiles. Is this do able and any know issues. I know on Linux/Unix
probably no biggy. But on Windows XP the installer takes control and
loads things into the system32 automatically for you with the new
version installed. Are their different dll's required for the different
versions of java and if so how do you keep it separate. Is it just as
easy as overlaying the system32 java.exe with the 1.4?


Thanks,

Frank

 

[Mike Schilling]

If this is not the correct forum for this question please let me know
which one as I looked and did not see a better one.

I need to run 2 version of java JVM/JDKs , 1.4.x and 1.5 on the same XP
machine but have different programs running using the different JVMs/JDK
compiles. Is this do able and any know issues. I know on Linux/Unix
probably no biggy. But on Windows XP the installer takes control and
loads things into the system32 automatically for you with the new version
installed. Are their different dll's required for the different versions
of java and if so how do you keep it separate. Is it just as easy as
overlaying the system32 java.exe with the 1.4?

Avoid using the system32 java.exe, since, as you point out, installers can
overwrite it. Install your JREs/JDKs into separate directories, and
whenever you run a java program, specifically point to the version of java
you want to run. This works fine.

 

[Monique Y. Mudama]

If this is not the correct forum for this question please let me
know which one as I looked and did not see a better one.

I need to run 2 version of java JVM/JDKs , 1.4.x and 1.5 on the same
XP machine but have different programs running using the different
JVMs/JDK compiles. Is this do able and any know issues. I know on
Linux/Unix probably no biggy. But on Windows XP the installer takes
control and loads things into the system32 automatically for you
with the new version installed. Are their different dll's required
for the different versions of java and if so how do you keep it
separate. Is it just as easy as overlaying the system32 java.exe
with the 1.4?

I do this all the time. Although the image of duelling JVMs is pretty
entertaining ...

 

[Daniel Dyer]

Avoid using the system32 java.exe, since, as you point out, installers
can
overwrite it. Install your JREs/JDKs into separate directories, and
whenever you run a java program, specifically point to the version of
java
you want to run. This works fine.

A variation on your suggestion:

Set the JAVA_HOME environment variable to point to one of the JDKs, then
add %JAVA_HOME%\bin to the PATH environment variable (include it before
any reference to system32).

Then change JAVA_HOME as required. You can do this at a system, user or
shell level so that you can mix and match your JVMs as required.

To the OP, could you not just use 1.5 and use the -source and -target
options when compiling 1.4 apps?

Dan.

 

[Roedy Green]

Is it just as
easy as overlaying the system32 java.exe with the 1.4?

I enjoyed your pun 'dueling" instead of "dual". Sometimes I just give
up and uninstall all but one.

see http://mindprod.com/jgloss/flipping.html

 

[andrewthommo]

I need to run 2 version of java JVM/JDKs , 1.4.x and 1.5 on the same XP
machine but have different programs running using the different JVMs/JDK
compiles.

This can be achieved by deploying the appliocations using Java
WebStart.
All your versioning problems will be over (though you may have to sign
or alter
the applications).

HTH