Emacs and Java

Emacs and Java

[Francesco Mazzoli]

Hi,

As much as I dislike Java, I find myself having to write Java code from time to
time, and I'm sure that a lot of you are in the same situation.

Given that, I find it very surprising that support for the Java language in
Emacs is abysmal.

I tried:

  * java-mode: does not support any modern Java construct, and with modern I
    mean >= Java 5 (generics, foreach loops, enums).
  * JDEE: seems to be completely unmaintained and barely working with modern
    emacsen, and lacking support for post-2004 Java as well.
  * malabar-mode <https://github.com/espenhw/malabar-mode/>: promises support
    for what JDEE is lacking.  Building with stock Maven and Emacs on Ubuntu
    12.04 fails.  There is a fork (<https://github.com/buzztaiki/malabar-mode>)
    that seems more maintained but building fails there as well with a different
    error.

So it seems that there is no way to at least edit comfortably Java code, let
alone have flymake, semantic features, etc.  This seems a huge gap in what is
the best editor out there.

Am I correct, or is there hope in some project I haven't considered?
malabar-mode seems to be the best candidate (if you can get it working) but
frankly I'm not that comfortable using it since it pulls a huge number of
dependencies and I don't want something to fancy anyway.

--
Francesco * Often in error, never in doubt

Re: Emacs and Java

[Eli Zaretskii]

> Date: Fri, 14 Sep 2012 12:25:12 +0100
> From: Francesco Mazzoli <f@mazzo.li>
> 
> So it seems that there is no way to at least edit comfortably Java code, let
> alone have flymake, semantic features, etc.  This seems a huge gap in what is
> the best editor out there.

Flymake is available (see flymake.el), and for semantic features try
global-ede-mode, and also look under lisp/cedet/semantic/.

I don't use Java, so I have no idea how well these support what you
need.

Re: Emacs and Java

[Francesco Mazzoli]

Hi Eli, thanks for the answer.

At Fri, 14 Sep 2012 16:28:56 +0300,
Eli Zaretskii wrote:
> Flymake is available (see flymake.el)

OK, I've tried flymake since apparently Java & ant are supported, and it can't
find my build file.  The docs mention a `flymake-buildfile-dirs' variable to
customise but it is not in the customisation group, and setting it has no
effect.

> and for semantic features try global-ede-mode, and also look under
> lisp/cedet/semantic/.

I'll take a look, thanks.

> I don't use Java, so I have no idea how well these support what you need.

Well the first thing would be to have a mode that actually highlights and
indents Java code (including generics, foreach loops, etc).  People have pointed
me at CEDET as well, I'll see if I can set that up.

--
Francesco * Often in error, never in doubt

Re: Emacs and Java

[Francesco Mazzoli]

At Fri, 14 Sep 2012 15:14:04 +0100,
Francesco Mazzoli wrote:
> OK, I've tried flymake since apparently Java & ant are supported, and it can't
> find my build file.  The docs mention a `flymake-buildfile-dirs' variable to
> customise but it is not in the customisation group, and setting it has no
> effect.

I've solved this problem, it was looking with `Makefile' and not for
`build.xml', replacing `flymake-simple-make-java-init' with
`flymake-simple-ant-java-init' in `flymake-allowed-file-name-masks' did the
trick.

--
Francesco * Often in error, never in doubt

Re: Emacs and Java

[Francesco Mazzoli]

At Fri, 14 Sep 2012 15:32:45 +0100,
Francesco Mazzoli wrote:
> I've solved this problem, it was looking with `Makefile' and not for
> `build.xml', replacing `flymake-simple-make-java-init' with
> `flymake-simple-ant-java-init' in `flymake-allowed-file-name-masks' did the
> trick.

...and now I've got another problem, it seems that it's not copying the files
correctly to whatever temp directory it seems to be using.  I took a look at the
sources that enable flymake for java and it looks pretty bare, I wonder if
anybody else has managed to get it working?

--
Francesco * Often in error, never in doubt

RE: Emacs and Java

[Ludwig, Mark]

> -----Original Message-----
> From: Francesco Mazzoli
> Sent: Friday, September 14, 2012 6:25 AM
> To: help-gnu-emacs@gnu.org
> Subject: Emacs and Java
> 
> Hi,
> 
> As much as I dislike Java, I find myself having to write Java code from time to
> time, and I'm sure that a lot of you are in the same situation.
> 
> Given that, I find it very surprising that support for the Java language in
> Emacs is abysmal.
> 
> I tried:
> 
>   * java-mode: does not support any modern Java construct, and with
> modern I
>     mean >= Java 5 (generics, foreach loops, enums).
>   * JDEE: seems to be completely unmaintained and barely working with
> modern
>     emacsen, and lacking support for post-2004 Java as well.
>   * malabar-mode <https://github.com/espenhw/malabar-mode/>:
> promises support
>     for what JDEE is lacking.  Building with stock Maven and Emacs on Ubuntu
>     12.04 fails.  There is a fork (<https://github.com/buzztaiki/malabar-mode>)
>     that seems more maintained but building fails there as well with a different
>     error.
> 
> So it seems that there is no way to at least edit comfortably Java code, let
> alone have flymake, semantic features, etc.  This seems a huge gap in what is
> the best editor out there.
> 
> Am I correct, or is there hope in some project I haven't considered?
> malabar-mode seems to be the best candidate (if you can get it working) but
> frankly I'm not that comfortable using it since it pulls a huge number of
> dependencies and I don't want something to fancy anyway.

I use cc-mode, which does a reasonable job for my Java work.

I have to confess to being unhappy about the fact that cc-mode knows nothing about the object-oriented nature of Java.  I make up for that myself through heavy use of tags, which I build with custom extras to pick up interface definitions.

Note further that I have not tried the current etags (v24), which might pick up interface definitions....

Hope this helps,
Mark

Re: Emacs and Java

[Grégoire Neuville]

Hello,

There is : https://github.com/senny/emacs-eclim

(haven't tried it though)

Otherwise if you're able and willing to, I strongly and heartily
advise you to switch to scala (http://www.scala-lang.org/ , fully
interoperable with java) ; then you could use
https://github.com/aemoncannon/ensime which is great.

Hope that will help,

G.N

On 14 September 2012 13:25, Francesco Mazzoli <f@mazzo.li> wrote:
> Hi,
>
> As much as I dislike Java, I find myself having to write Java code from time to
> time, and I'm sure that a lot of you are in the same situation.
>
> Given that, I find it very surprising that support for the Java language in
> Emacs is abysmal.
>
> I tried:
>
>   * java-mode: does not support any modern Java construct, and with modern I
>     mean >= Java 5 (generics, foreach loops, enums).
>   * JDEE: seems to be completely unmaintained and barely working with modern
>     emacsen, and lacking support for post-2004 Java as well.
>   * malabar-mode <https://github.com/espenhw/malabar-mode/>: promises support
>     for what JDEE is lacking.  Building with stock Maven and Emacs on Ubuntu
>     12.04 fails.  There is a fork (<https://github.com/buzztaiki/malabar-mode>)
>     that seems more maintained but building fails there as well with a different
>     error.
>
> So it seems that there is no way to at least edit comfortably Java code, let
> alone have flymake, semantic features, etc.  This seems a huge gap in what is
> the best editor out there.
>
> Am I correct, or is there hope in some project I haven't considered?
> malabar-mode seems to be the best candidate (if you can get it working) but
> frankly I'm not that comfortable using it since it pulls a huge number of
> dependencies and I don't want something to fancy anyway.
>
> --
> Francesco * Often in error, never in doubt
>



--
Grégoire Neuville


-- 
Grégoire Neuville

Re: Emacs and Java

[Francesco Mazzoli]

At Fri, 14 Sep 2012 18:29:44 +0200,
Grégoire Neuville wrote:
> There is : https://github.com/senny/emacs-Clim
> 
> (haven't tried it though)

Thanks, but I'd rather avoid Eclipse... but I'll keep that project in mind.
 
> Otherwise if you're able and willing to, I strongly and heartily advise you to
> switch to scala (http://www.scala-lang.org/ , fully interoperable with java) ;
> then you could use https://github.com/aemoncannon/ensime which is great.

If I could choose not to use Java I would not use it (I wouldn't choose Scala
either, but that's another discussion).

--
Francesco * Often in error, never in doubt

Re: Emacs and Java

[Tom]

Francesco Mazzoli <f <at> mazzo.li> writes:

> 
> At Fri, 14 Sep 2012 18:29:44 +0200,
> Grégoire Neuville wrote:
> > There is : https://github.com/senny/emacs-Clim
> > 
> > (haven't tried it though)
> 
> Thanks, but I'd rather avoid Eclipse... but I'll keep that project in mind.
> 

I don't think you can get the language support which Eclipse provides
using only Emacs, so eclim is a good compromise, because with it you
can keep working in Emacs and Eclipse is used only as a backend which
provides the smart features Emacs lacks.

Re: Emacs and Java

[Leo]

On 2012-09-14 19:25 +0800, Francesco Mazzoli wrote:
> As much as I dislike Java, I find myself having to write Java code from time to
> time, and I'm sure that a lot of you are in the same situation.

Writing java in emacs is only better than writing it in notepad.
Probably why some veteran emacs hackers leave emacs for IDEs if they
have to hack java day in and day out! You can customise the hell out of
emacs and it will never even come close to any good java IDE. Emacs
simply doesn't understand java or understand it in a retarded way (i.e.
it can do some code completion with a speed nobody can tolerate).

Sorry to say these things.

Leo

Re: Emacs and Java

[Francesco Mazzoli]

At Sat, 15 Sep 2012 08:53:47 +0800,
Leo wrote:
> Writing java in emacs is only better than writing it in notepad.  Probably why
> some veteran emacs hackers leave emacs for IDEs if they have to hack java day
> in and day out! You can customise the hell out of emacs and it will never even
> come close to any good java IDE. Emacs simply doesn't understand java or
> understand it in a retarded way (i.e.  it can do some code completion with a
> speed nobody can tolerate).

There is no reason whatsoever why this has to be the case, emacs has excellent
support (either out of the box or via third party packages) for most languages.
The problem is that most people just give up and use big IDEs, which I truly
loathe - I'd rather code in the current emacs setup than in an IDE.

--
Francesco * Often in error, never in doubt

Re: Emacs and Java

[Eli Zaretskii]

> Date: Sat, 15 Sep 2012 08:27:31 +0100
> From: Francesco Mazzoli <f@mazzo.li>
> 
> At Sat, 15 Sep 2012 08:53:47 +0800,
> Leo wrote:
> > Writing java in emacs is only better than writing it in notepad.  Probably why
> > some veteran emacs hackers leave emacs for IDEs if they have to hack java day
> > in and day out! You can customise the hell out of emacs and it will never even
> > come close to any good java IDE. Emacs simply doesn't understand java or
> > understand it in a retarded way (i.e.  it can do some code completion with a
> > speed nobody can tolerate).
> 
> There is no reason whatsoever why this has to be the case, emacs has excellent
> support (either out of the box or via third party packages) for most languages.
> The problem is that most people just give up and use big IDEs, which I truly
> loathe - I'd rather code in the current emacs setup than in an IDE.

Way to go!

Please submit any changes you feel are necessary to
emacs-devel@gnu.org, or, better yet, file a bug with the patches using
"M-x report-emacs-bug RET".

People who want to improve Emacs support for IDE-like development
environment with modern features are encouraged to make improvements
and submit them, and generally work on improving them, rather than
whine about Emacs being "slightly better than Notepad".  That kind of
attitude will never get you any closer to your goal.

You can sit on the fence laughing at Emacs and waiting for others to
do the job, or you can jump in, bite the bullet, and do something to
advance Emacs into the future.  Your call.

Re: Emacs and Java

[Jambunathan K]

> People who want to improve Emacs support for IDE-like development
> environment with modern features are encouraged to make improvements
> and submit them, and generally work on improving them, rather than
> whine about Emacs being "slightly better than Notepad".  That kind of
> attitude will never get you any closer to your goal.

My feeling exactly.  There is a popular saying.
  Don't look a gift horse in the mouth

There is also a sense of entitlement that is exhibited by users.  It is
surprising to find this attitude even among people who are NOT NEW to
FLOSS or it's mailing lists.

The problem is a lack of awareness of "What the goals of a particular
mode of organization is" or "How things work or what actually works in
this organization"?

I am using "organization" in it's broadest terms - "a voluntary
association of people".

I think a sense of entitlement shouldn't even be exhibited by members
who make annual subscription to FSF.  They have right *not* to renew
their subscription if they feel that their interests are not taken care
of.  If people stop donating stuff - membership fees, volunteer effort,
material/infrastructural stuff to FSF - then it's survival becomes
difficult if not impossible (even though the goals that FSF subscribes
to is needed for society in general)

I think world will be a better place if people show support or reject
support by concrete (strategic) action rather than voicing their
feelings and opinions.  (Note that voicing opinion in itself is *also* a
strategic action, but one who shouts should also consider whether he is
shouting alone, an empty room, a crowd etc.)

If people understand how "Carrot and Stick" works and use it to further
their own goals and the goals that they desire for community in general
then, I believe, goodness will grow and evil will subside.

Note that a single carrot or a stick would suffice to influence a single
horse.  But a sack of carrots or a mountain load of it is needed to
influence a herd.

I believe there is sufficient loyal crowd of Emacs users, I can swear
that it would take enormous effort for me *NOT* to use Emacs.  This
irrespective of whether Emacs lacks support for stuff I badly need.
-- 

Re: Emacs and Java

[Jambunathan K]

Jambunathan K <kjambunathan@gmail.com> writes:

> I think a sense of entitlement shouldn't even be exhibited by members
> who make annual subscription to FSF.

A typical donor - be it a member or a user - is agreeing to support FSF
in broader terms even though he could be doing it with narrow interests.

There is no reason well-meaning donor(s) can commission a specific work,
hire engineers (in the usual sense) and have that WORK donated to
Emacs/FSF.  Considering FSF goals, I think such an effort and donation
will be more valuable than mere annual subscription.

Working out the logistics and organizing such a thing may be beyond the
means of average Joe or Joes.  At the minimum, an average Joe should
understand either his unwillingness to do such work or accept his
incompetence in doing so.
-- 

Re: Emacs and Java

[Francesco Mazzoli]

At Sat, 15 Sep 2012 16:47:55 +0530,
Jambunathan K wrote:
> There is also a sense of entitlement that is exhibited by users.  It is
> surprising to find this attitude even among people who are NOT NEW to FLOSS or
> it's mailing lists.

I'm not sure if you're referring to me, I don't feel entitled to anything, but
I'm genuinely surprised that a language like Java is so poorly supported in
Emacs, and I'd like to get to a situation where programming in Java in Emacs is
a bit better.  I didn't read the rest of the email because it looked liked like
a boring rant.

...and yes, I am a FSF member :).

--
Francesco * Often in error, never in doubt

Re: JDEE help (was: Emacs and Java)

[Francesco Mazzoli]

In the end I've bitten the bullet, pulled a fresh svn copy of JDEE, built it and
somehow managed to get it working.

This is my config, mostly taken from the emacswiki article
<http://emacswiki.org/emacs/JavaDevelopmentEnvironment>:

---------------8<---------------

(add-to-list 'load-path (expand-file-name "~/.emacs.d/site-lisp/jdee/lisp"))

(setq semantic-default-submodes '(global-semantic-idle-scheduler-mode
                                  global-semanticdb-minor-mode
                                  global-semantic-idle-summary-mode
                                  global-semantic-stickyfunc-mode
                                  global-semantic-mru-bookmark-mode))

(setq semantic-load-turn-everything-on t)
(semantic-mode 1)
(require 'semantic)
(require 'semantic/senator)
(require 'semantic/ia)
(require 'semantic/wisent)
(require 'semantic/wisent/java-tags)

(setq jde-auto-parse-enable nil)
(setq jde-enable-senator nil)
(load "jde-autoload")

(require 'jde)

(setq jde-ant-enable-find t
      jde-build-function 'jde-ant-build
      jde-ant-args "compile")

(add-to-list 'auto-mode-alist '("\\.java\\'" . jde-mode))

(push 'jde-mode ac-modes)

(setq  jde-jdk '("1.7")
       jde-jdk-registry '(("1.6" . "/usr/lib/jvm/java-1.6.0-openjdk-amd64")
                          ("1.7" . "/usr/lib/jvm/java-1.6.0-openjdk-amd64")))

(define-key jde-mode-map (kbd "<f5>") 'jde-build)
(define-key jde-mode-map (kbd "<f6>") 'jde-run)

(defun java-hooks ()
  (menu-bar-mode 1)
  (wisent-java-default-setup)
  (setq c-basic-offset 4)
  (setq fill-column 90)
  (setq whitespace-line-column 90)
  (jde-abbrev-mode))

(add-hook 'jde-mode-hook 'java-hooks)
(add-hook 'java-mode-hook 'java-hooks)

--------------->8---------------

Then for each project I have I create a `prj.el' file something like

  (jde-project-file-version "1.0")
  (jde-set-variables)
  (setq jde-global-classpath '("/path/where/project/classes/are"))
  (setq bsh-classpath '("/path/where/project/classes/are"))

This is already a huge improvement, the semantic mode works, and I can compile
and run java classes easily.

However, I still need some help to make some feature work:

  * proper completion: right now, if I press `C-c C-v .' the completion works,
    but only for classes outside my project.  I'm afraid that jde is not picking
    up the project classpath for some reason, or something else is going wrong.
    Is there a way to force a reload of the classes?

  * completion with auto-complete: is it possible to bind in some way the jdee
    completions with auto-complete?  I could define the ac sources manually but
    maybe there is something already...

  * beanshell: similar to the problem above, beanshell works (miracle!) but my
    project classpath is not included.  As you can see I set `bsh-classpath' but
    it does not seem to have an effect.

  * syntax highlighting: while semantic seems to parse java correctly (I think
    that `wisent-java-default-setup' should provide an improved parser),
    generics & co. are still not highlighted.  Is there a way to make that work?

  * tags and semantics: this is more of a semantics question, but I'd like to
    jump to semantics tags when I press `M-.' instead of having to type the
    horrible `C-c , J' and then specify the name manually.

  * flymake: this is not essential, but is it possible to tie the jde
    compilation (`jde-build') to flymake?

When I'm done with this I'll write a wiki page documenting the steps to take, I
think that with enough configuration JDEE could be the solution.

Thanks,
Francesco.

Re: JDEE help (was: Emacs and Java)

[Eli Zaretskii]

> Date: Sat, 15 Sep 2012 08:22:24 +0100
> From: Francesco Mazzoli <f@mazzo.li>
> Cc: jdee-users@lists.sourceforge.net
> 
> In the end I've bitten the bullet, pulled a fresh svn copy of JDEE, built it and
> somehow managed to get it working.
> 
> This is my config, mostly taken from the emacswiki article
> <http://emacswiki.org/emacs/JavaDevelopmentEnvironment>:
> [...]
> This is already a huge improvement, the semantic mode works, and I can compile
> and run java classes easily.
> 
> However, I still need some help to make some feature work:

Could you please start a discussion on emacs-devel@gnu.org with these
questions?  The CEDET developers might give you some useful advice
there, and perhaps also the JDEE developers and users.

Thanks!

Forward: Re: JDEE help (was: Emacs and Java)

[Francesco Mazzoli]

[-- Attachment #1: Type: text/plain, Size: 159 bytes --]

Hi,

Eli Zaretskii suggested this mailing list for this discussion, you can follow
the original thread here: <http://thread.gmane.org/gmane.emacs.help/86761>


[-- Attachment #2: Type: message/rfc822, Size: 8034 bytes --]

From: Francesco Mazzoli <f@mazzo.li>
To: help-gnu-emacs@gnu.org
Cc: jdee-users@lists.sourceforge.net
Subject: Re: JDEE help (was: Emacs and Java)
Date: Sat, 15 Sep 2012 08:22:24 +0100
Message-ID: <87a9wrpx73.wl%f@mazzo.li>

In the end I've bitten the bullet, pulled a fresh svn copy of JDEE, built it and
somehow managed to get it working.

This is my config, mostly taken from the emacswiki article
<http://emacswiki.org/emacs/JavaDevelopmentEnvironment>:

---------------8<---------------

(add-to-list 'load-path (expand-file-name "~/.emacs.d/site-lisp/jdee/lisp"))

(setq semantic-default-submodes '(global-semantic-idle-scheduler-mode
                                  global-semanticdb-minor-mode
                                  global-semantic-idle-summary-mode
                                  global-semantic-stickyfunc-mode
                                  global-semantic-mru-bookmark-mode))

(setq semantic-load-turn-everything-on t)
(semantic-mode 1)
(require 'semantic)
(require 'semantic/senator)
(require 'semantic/ia)
(require 'semantic/wisent)
(require 'semantic/wisent/java-tags)

(setq jde-auto-parse-enable nil)
(setq jde-enable-senator nil)
(load "jde-autoload")

(require 'jde)

(setq jde-ant-enable-find t
      jde-build-function 'jde-ant-build
      jde-ant-args "compile")

(add-to-list 'auto-mode-alist '("\\.java\\'" . jde-mode))

(push 'jde-mode ac-modes)

(setq  jde-jdk '("1.7")
       jde-jdk-registry '(("1.6" . "/usr/lib/jvm/java-1.6.0-openjdk-amd64")
                          ("1.7" . "/usr/lib/jvm/java-1.6.0-openjdk-amd64")))

(define-key jde-mode-map (kbd "<f5>") 'jde-build)
(define-key jde-mode-map (kbd "<f6>") 'jde-run)

(defun java-hooks ()
  (menu-bar-mode 1)
  (wisent-java-default-setup)
  (setq c-basic-offset 4)
  (setq fill-column 90)
  (setq whitespace-line-column 90)
  (jde-abbrev-mode))

(add-hook 'jde-mode-hook 'java-hooks)
(add-hook 'java-mode-hook 'java-hooks)

--------------->8---------------

Then for each project I have I create a `prj.el' file something like

  (jde-project-file-version "1.0")
  (jde-set-variables)
  (setq jde-global-classpath '("/path/where/project/classes/are"))
  (setq bsh-classpath '("/path/where/project/classes/are"))

This is already a huge improvement, the semantic mode works, and I can compile
and run java classes easily.

However, I still need some help to make some feature work:

  * proper completion: right now, if I press `C-c C-v .' the completion works,
    but only for classes outside my project.  I'm afraid that jde is not picking
    up the project classpath for some reason, or something else is going wrong.
    Is there a way to force a reload of the classes?

  * completion with auto-complete: is it possible to bind in some way the jdee
    completions with auto-complete?  I could define the ac sources manually but
    maybe there is something already...

  * beanshell: similar to the problem above, beanshell works (miracle!) but my
    project classpath is not included.  As you can see I set `bsh-classpath' but
    it does not seem to have an effect.

  * syntax highlighting: while semantic seems to parse java correctly (I think
    that `wisent-java-default-setup' should provide an improved parser),
    generics & co. are still not highlighted.  Is there a way to make that work?

  * tags and semantics: this is more of a semantics question, but I'd like to
    jump to semantics tags when I press `M-.' instead of having to type the
    horrible `C-c , J' and then specify the name manually.

  * flymake: this is not essential, but is it possible to tie the jde
    compilation (`jde-build') to flymake?

When I'm done with this I'll write a wiki page documenting the steps to take, I
think that with enough configuration JDEE could be the solution.

Thanks,
Francesco.



--
Francesco * Often in error, never in doubt

Re: JDEE help

[Philipp Haselwarter]

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Here's the java section from my config; it's kind of hacky but it used
to wort for auto-complete and flyspell. It hasn't been tested in about a
year and could certainly use some clean-up. I also throw in an example
prj.el.

Personally I hope that cedet will some time soon get to the point where
it fulfills most java requirements. It might actually be there already
(haven't coded in java for some time); it's certainly the way to go.



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-- 
Philipp Haselwarter