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Java Forum / General / November 2006

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Java 1.4 vs 1.5 Differences

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Peter - 18 Oct 2006 20:47 GMT
Greetings,

I've begun work on updating a java 1.4 stand alone application to work
with Java 1.5. It has some major problems with new version of Java.

I've been trying to find a summary list of differences between the Java
versions for someone familiar with Java 1.4.

-ie. Enums is now a reserved word in Java 1.5 (or at least I think it
is :)

Would anyone know of a summary list of changes between Java 1.4 and
1.5?

Thanks,
-peter
Jean-Francois Briere - 18 Oct 2006 21:23 GMT
> -ie. Enums is now a reserved word in Java 1.5 (or at least I think it is :)

enum (and not Enum) is now a reserved word :-)
For the reserved words in Java have a look at this:
http://java.sun.com/docs/books/tutorial/java/nutsandbolts/_keywords.html

> Would anyone know of a summary list of changes between Java 1.4 and 1.5?

There are many many many new features!!! Have a look at this:
http://java.sun.com/j2se/1.5.0/docs/relnotes/features.html

Regards
Peter - 25 Oct 2006 17:24 GMT
Thanks guys,

I'll take your advice to heart and start reading through the Java 1.5
docs. (its so painful :) I'm also taking this as an opportunity study
and get my Java Programmer Certification. (seams like a good time)

Thanks again,
-peter
PS: Most Java programmers I talk to have had the same question as me,
so hopefuly this post will answer the basic question. (I hope it wasn't
already asked, I looked for it :)

> > -ie. Enums is now a reserved word in Java 1.5 (or at least I think it is :)
>
[quoted text clipped - 8 lines]
>
> Regards
Arne Vajhøj - 19 Oct 2006 01:35 GMT
> Would anyone know of a summary list of changes between Java 1.4 and
> 1.5?

Those I consider most important:
* auto boxing/unboxing
* generics
* annotations
* java.util.concurrent
* enum
* variable number of arguments
* new for loop (it is not called foreach but is foreach)
* import static
* printf

Arne
Peter - 20 Oct 2006 15:26 GMT
Right thanks!

My hope was to find out how much I needed to look into this. Reading
the Sun documentation is rarely umm fun :) Sounds like quite a bit is
different, I'll probably take the new Java 1.5 Cert.

Thanks again
-peter

> > Would anyone know of a summary list of changes between Java 1.4 and
> > 1.5?
[quoted text clipped - 11 lines]
>
> Arne
Arne Vajhøj - 21 Oct 2006 00:07 GMT
> My hope was to find out how much I needed to look into this. Reading
> the Sun documentation is rarely umm fun :) Sounds like quite a bit is
> different, I'll probably take the new Java 1.5 Cert.

Java 1.5 was a huge change to Java compared to 1.3 and 1.4 (and 1.6).

Arne
Lew - 21 Oct 2006 01:36 GMT
Peter wrote:
>> My hope was to find out how much I needed to look into this. Reading
>> the Sun documentation is rarely umm fun :) Sounds like quite a bit is
>> different, I'll probably take the new Java 1.5 Cert.

"Fun" is relative.  Personally I love reading Sun's documentation, but then
some people like to eat fruitcake.

If you do learn to enjoy Sun's docs, then you will accelerate your learning.
They really do explain a lot.

- Lew
Thomas Weidenfeller - 19 Oct 2006 08:19 GMT
> Would anyone know of a summary list of changes between Java 1.4 and
> 1.5?

Why don't you read Sun's release notes for 1.5?

/Thomas
Signature

The comp.lang.java.gui FAQ:
http://gd.tuwien.ac.at/faqs/faqs-hierarchy/comp/comp.lang.java.gui/
ftp://ftp.cs.uu.nl/pub/NEWS.ANSWERS/computer-lang/java/gui/faq

Hulker69 - 19 Oct 2006 22:37 GMT
>Greetings,
>
[quoted text clipped - 12 lines]
>Thanks,
>-peter

I used the O'Reilly "Java 1.5 Tiger - A Developer's Notebook" book
which covers most of the relevant stuff (at least to the point where
it becomes useful).

ISBN here in UK is 0-596-00738-8

Look on www.oreilly.com as well.
Mike  Schilling - 19 Oct 2006 22:39 GMT
> Greetings,
>
[quoted text clipped - 9 lines]
> Would anyone know of a summary list of changes between Java 1.4 and
> 1.5?

Are you asking specifically for incompatibilities?  If so, there's:

* enum is now a keyword
* generics will cause millions of ineradicable warnings in any code that
uses collections
* probably others I'm unaware of
ddimitrov - 20 Oct 2006 05:13 GMT
This doc could be a good starting point:
http://java.sun.com/j2se/JM_White_Paper_R6A.pdf
Richard Wheeldon - 25 Oct 2006 19:57 GMT
> I've begun work on updating a java 1.4 stand alone application to work
> with Java 1.5. It has some major problems with new version of Java.

Ignoring the features and concentrating on the regressions:

1. Thread priorities are broken when using synchronized objects.

2. Under certain window managers under Linux/Unix you'll get a
blank screen instead of your app. Use pack() before setting the
size of the window to fix this.

3. Some of the default fonts have changed - not really much of
a regression but it will mean any screen shots, etc. are now out
of date :(

Richard
Andrew Thompson - 25 Oct 2006 23:35 GMT
...
> 2. Under certain window managers under Linux/Unix you'll get a
> blank screen instead of your app. Use pack() before setting the
> size of the window to fix this.

pack() should not be regarded as a 'fix'.  In fact, if you
actually need to call setSize() at all, it is a strong hint
that some components do not return a sensible
preferredSize(), and should be fixed.

Andrew T.
ThomasH - 27 Oct 2006 19:01 GMT
Richard Wheeldon wrote on 25-Oct-06 11:57:
>> I've begun work on updating a java 1.4 stand alone application to work
>> with Java 1.5. It has some major problems with new version of Java.
[quoted text clipped - 12 lines]
>
> Richard

...as well as many AWT/Swing application are broken with JDK1.5!
Just one small example: JWindow does not appear with proper
background, sometimes it will not be repainted. (My custom made
tooltip worked since JDK1.1 with Swing addition without a change.)

This list is long, I have some whopping 85 topics on my list already,
for AWT and Swing alone. I am sticking to jdk1.4 for now, I do
standalone applications and I do not care about the deployment of
the plugin.  Good for me, but many of you will have to port and/or
get the stuff fixed.

This new Java is really a symptom of a sickness, pardon me if
you disagree, but this is my take:

Good language is a stable language. Java seems to be growing and
growing toward titanic dimensions, leaving former behemoths like
PL/1, ADA and C++ in shadows.  And this causes that teams at Sun
are no more capable of providing iron clad quality of this now so
gigantic product. So far the quadratic growth, or rather explosion
in size, was limited to the public classes.  Now it took over the
language itself, and this is bad news, regardless how much you
might like or chose to ignore some of these novelties.

The Pandora's box is open.

Let me reach toward past, as James Gosling presented Java
philosophy in regards of syntax and semantics. His vision was
borne after learning from the case of C++, with its ambiguities,
need for re-parsing, context sensitive cases etc. Maintenance
was a nightmare. Gosling said, (I paraphrase of course) that if
a compiler cannot resolve a language construct, than how a human
can? Java was designed to be better, to stick with LALR(1) type
of grammar and thus to be easy to parse and be easy to read by
humans.

Now the group of experts introduces these unholy generics "boxes"
resembling C++ templates.  The problem with this syntax is that
is uses tokens which have the right to not paired. We can always
relay on () or [] or {} pairs, but not on <>, these are components
of expressions. Needless to say, many editors will not be able to
support such syntax, vi for example, I use the "%" key to jump
to paired element all the time. I am not sure at this time if
any visual illusions 'a la C++' can be now created with this
boxing/generics scheme of theirs.

I am asking myself, why this lack of fantasy and imagination
strikes people so often, why this copy-ism of someone else's
solution takes over so often? We have so many completely
different languages, Eiffel, Haskil, Smalltalk... Why not
to go shopping for a while for something more Java'ish and new?

Some of you might recall the PL/1 case: IBM forced a development
of a lingua franca for the future and failed. Designers of
PL/1 were so enticed by Fortran, that they made the language
look like Fortran on steroids. Many syntactic elements were
almost identical, but with devious semantic differences in
some cases... (!)  Over the time this has proven a deadly
ingredient to cause some serious havoc. We have had many well
documented cases of severe failures in financial, technical
and military applications alike. Remember the FORMAT case,
which rounded floating point values just a bit different in
some cases on these pesky bills, and the resulting law suits
and fraud charges...

Java goes now officially the same way, "Congratulations"
to the expert group, I mean it sarcastic. Please, please
stop adding things to Java at last. You done, done for good.
Freeze it.

Thomas
Richard Wheeldon - 27 Oct 2006 23:27 GMT
> This list is long, I have some whopping 85 topics on my list already,
> for AWT and Swing alone.

Any chance of posting these - before I run into them?

Richard
ThomasH - 02 Nov 2006 19:51 GMT
Richard Wheeldon wrote on 27-Oct-06 15:27:
>> This list is long, I have some whopping 85 topics on my list already,
>> for AWT and Swing alone.
>
> Any chance of posting these - before I run into them?
>
> Richard

I will try, however I am swamped currently and as I
said I am in the luxury to ask people to run our
product with jdk1.4.

I usually work on posting them to java bug parade.
Its a proper place to get a chance to get them
fixed, however not really for sure. See how dated
some of these bugs are. They are flooded by new
functionality and so the "old stuff" seem so
irrelevant...

Thomas


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