From cmehta82 at gmail.com  Wed Sep  1 10:32:12 2010
From: cmehta82 at gmail.com (Chirag Mehta)
Date: Wed, 1 Sep 2010 23:02:12 +0530
Subject: [Mirror-dev] A Very Small Query
Message-ID: <AANLkTi=Q3wwXF3FpOtUxHjzWiEcfxj1GOsRainO4TQmL@mail.gmail.com>

Hi,

I have seen this API today itself for the first time and I am not a very big
expert, even I am just merely 5 years experience software engineer, please
excuse me if I make a wrong statement.


I have seen a piece of code on your site, which was written as below:



Reflect a field by name (will return null if not found):

Class clazz;

Field f = new Mirror().on(clazz).reflect().field("fieldName");



Reflecting all fields of a class (will return an empty list if none found):

Class clazz;

List<Field> l = new Mirror().on(clazz).reflectAll().fields();



Reflecting all fields of a class that matches a Matcher<Field> (will return
an empty list if none found):

Class clazz;

List<Field> l = new Mirror().on(clazz).reflectAll().fieldsMatching(new
YourCustomMatcher());



Great efforts, I have used reflection in very dirty way and this is much
simpler and cleaner way no doubt. The thing which annoyed me was ?*new
Mirror()?*. A new object reference is required which may not be required
further in future.



Please explain me the decision which made this usage, like why you didn?t
prefer it to make a Util... for example



Reflect a field by name (will return null if not found):

Class clazz;

Field f = *MirrorUtil.onClassReflectField(clazz, "fieldName");*



Reflecting all fields of a class (will return an empty list if none found):

Class clazz;

List<Field> l = *MirrorUtil.onClassReflectAllFields(clazz, "fieldName");*

Reflecting all fields of a class that matches a Matcher<Field> (will return
an empty list if none found):



Class clazz;

List<Field> l = *MirrorUtil.onClassReflectAllFieldsMatching(clazz, new
YourCustomMatcher());*



I am sure you did think about this type of option, but I am curious why
didn?t it has been used. You know the Java world is too much dependent on
OOPS and Garbage Collection is very heavy operation.



Regards

Chirag
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From jonas at vidageek.net  Thu Sep  2 10:03:36 2010
From: jonas at vidageek.net (Jonas Abreu)
Date: Thu, 2 Sep 2010 14:03:36 -0300
Subject: [Mirror-dev] A Very Small Query
In-Reply-To: <AANLkTi=Q3wwXF3FpOtUxHjzWiEcfxj1GOsRainO4TQmL@mail.gmail.com>
References: <AANLkTi=Q3wwXF3FpOtUxHjzWiEcfxj1GOsRainO4TQmL@mail.gmail.com>
Message-ID: <AANLkTikD6xYp7fBmOxE5eZMPLD4ZofTkz5oruTvzP06C@mail.gmail.com>

Hi Chirag,

Basically that was exactly what we where trying to get away from. A
single class that have all the logic inside it and that is somewhat
harder to test.

While developing Mirror, we really tried to focus on readability. Even
though MirrorUtil.onClassReflectAllFieldsMatching(clazz, new
YourCustomMatcher()) is quite easy to read, we believe that having the
parameters close to the dsl part that is referring to them makes the
dsl easier to read.

Another reason not to use the static approach was allowing for a
ReflectionProvider, that can be used to change how reflection is done
(for example, there is a reflection provider that uses internal sun
classes to speed things up).

Also, garbage collectors are quite smart. Unless you ask for a full gc
(with System.gc) it will be really fast collecting short-lived objects
(this is a good post on the subject
http://java.dzone.com/articles/gc-goodstuff-collector).

Hope I could clarify your doubts.

Regards,

Jonas Abreu

VidaGeek.net
http://vidageek.net

Adaptworks - Coaching you to the change
http://www.adaptworks.com.br



On Wed, Sep 1, 2010 at 2:32 PM, Chirag Mehta <cmehta82 at gmail.com> wrote:
> Hi,
>
> I have seen this API today itself for the first time and I am not a very big
> expert, even I am just merely 5 years experience software engineer, please
> excuse me if I make a wrong statement.
>
> I have seen a piece of code on your site, which was written as below:
>
>
>
> Reflect a field by name (will return null if not found):
>
> Class clazz;
>
> Field f = new Mirror().on(clazz).reflect().field("fieldName");
>
>
>
> Reflecting all fields of a class (will return an empty list if none found):
>
> Class clazz;
>
> List<Field> l = new Mirror().on(clazz).reflectAll().fields();
>
>
>
> Reflecting all fields of a class that matches a Matcher<Field> (will return
> an empty list if none found):
>
> Class clazz;
>
> List<Field> l = new Mirror().on(clazz).reflectAll().fieldsMatching(new
> YourCustomMatcher());
>
>
>
> Great efforts, I have used reflection in very dirty way and this is much
> simpler and cleaner way no doubt. The thing which annoyed me was ?new
> Mirror()?. A new object reference is required which may not be required
> further in future.
>
>
>
> Please explain me the decision which made this usage, like why you didn?t
> prefer it to make a Util... for example
>
>
>
> Reflect a field by name (will return null if not found):
>
> Class clazz;
>
> Field f = MirrorUtil.onClassReflectField(clazz, "fieldName");
>
>
>
> Reflecting all fields of a class (will return an empty list if none found):
>
> Class clazz;
>
> List<Field> l = MirrorUtil.onClassReflectAllFields(clazz, "fieldName");
>
> Reflecting all fields of a class that matches a Matcher<Field> (will return
> an empty list if none found):
>
>
>
> Class clazz;
>
> List<Field> l = MirrorUtil.onClassReflectAllFieldsMatching(clazz, new
> YourCustomMatcher());
>
>
>
> I am sure you did think about this type of option, but I am curious why
> didn?t it has been used. You know the Java world is too much dependent on
> OOPS and Garbage Collection is very heavy operation.
>
>
>
> Regards
>
> Chirag
>
> _______________________________________________
> Mirror-dev mailing list
> Mirror-dev at lista.vidageek.net
> http://lista.vidageek.net/listinfo.cgi/mirror-dev-vidageek.net
>
>