[Back Porting] Classpath and other

[Java script Dude]

I am in need of back porting some libraries back from Java 1.4.2 to
1.3.1, namely
AbstractMap.java, HashMap.java, HashSet.java, LinkedHashMap.java &
LinkedHashSet.java.

Being stuck with 1.3.1n by an application vendor, I would love to be
able to use json-rpc-java libraries but they are coded for 1.4.

[q1] Where should I put these files in the classpath to ensure that
they get picked instead of the core JRE libraries (AbstractMap,
HashMap, HashSet)

[q2] Can any body think of any issues that arise from back porting
source to earlier java environments.

Note: we are using tons of third party libraries and frameworks for our
application. I am a little concerned about causing some obscure issues
with this code. Debugging such issues would be extremely troublesome.

Thanks!
JsD

 

[Thomas Hawtin]

I am in need of back porting some libraries back from Java 1.4.2 to
1.3.1, namely
AbstractMap.java, HashMap.java, HashSet.java, LinkedHashMap.java &
LinkedHashSet.java.

Being stuck with 1.3.1n by an application vendor, I would love to be
able to use json-rpc-java libraries but they are coded for 1.4.

[q1] Where should I put these files in the classpath to ensure that
they get picked instead of the core JRE libraries (AbstractMap,
HashMap, HashSet)

[q2] Can any body think of any issues that arise from back porting
source to earlier java environments.

Under what license are you attempting to do this under? The terms are
generally very strict and don't allow alteration of boot classes.

I'd ditch the app vendor sharpish. 1.3 has been in end-of-life since
last year.

Tom Hawtin

 

[Andrew Thompson]

Java script Dude wrote:
...

Being stuck with 1.3.1n by an application vendor, ..

Why? Create yourself a Webstart launch file for that
application - specifying 1.3.1, and run 1.5 for the
rest of your system.

( But then, assuming the app. vendor is unable to provide
the webstart file themselves, and is sticking to 1.3.1 -
Thomas' advice to 'ditch the app vendor sharpish' seems
sound to me. )

 

[Roedy Green]

[q1] Where should I put these files in the classpath to ensure that
they get picked instead of the core JRE libraries (AbstractMap,
HashMap, HashSet)

Modifying system classes is cheating as is writing classes in the java
/ javax package tree.

I think you will need to replace the classes in rt.jar.

This might turn into one of those nightmare "loose bedspread thread"
projects where you try to pull out a loose thread and it keeps on
unravelling.

A tiny change to one class precipitates rippling changes in other
classes. It should not happen, but make sure before embarking.

You will be in legal trouble if you sell any product with such mods.

To do this legally, you will need to implement those classes yourself
in your own package.

 

[Roedy Green]

Being stuck with 1.3.1n by an application vendor

This vendor sounds moribund. It is only a matter of time until you
have to rewrite without relying on him. Biting the bullet now will be
cheaper than later.