WWDC2001 Session 605

Transcript

Kind: captions
Language: en
hi thank you for joining us I'm glad to
see a good number of you found your way
back over to the conference center to
catch up with the rest of our sessions
our next session is going to be moving
to web objects 5 so I'd like to
introduce Melissa Turner from the
engineering team to come up and start
the possession app well as Tony told you
my name is Melissa I'm one of the web
objects development deployment engineers
and I'm gonna be your presenter for the
next hour or so I'm first we might as
well get it out of the way yes I'm an
engineer yes I'm female sometimes it
happens this is the session 605 moving
to web objects and I hit the wrong
direction the session assumes that you
have some knowledge of web objects we're
primarily going to concern concentrate
on some of the conversion issues for
those of you who have a web objects-- 4
or 5 or web objects 4 or 5 one
application that you want to move to of
objects 5 we're going to cover some of
the benefits of moving to web objects 5
we're going to cover how you would go
about migrating an application to web
objects 5 and we're going to talk about
some of the new improvements and some of
the features in the web objects 5
frameworks I am NOT going to cover
anything in depth I'm not going to cover
a Oh F for Java client we have entire
sessions devoted to those some of them I
believe there's one following this I
recommend it highly and but remember
anything that I don't cover is going to
be covered elsewhere what is web objects
5 this is a question we've gotten from
several people web objects 5 is
essentially web objects 4 5 1 ported to
Java it has the same feature set
it's got essentially the same API as web
objects 4 5 there's a few exceptions
that we'll talk about later on Windows
it uses the 4 5 developer tools that
you're all familiar with we have a new
project builder as you all know on
ten and we have integrated with that yo
modeler whoa builder and the rule editor
have been Akwa fide but other than that
they're pretty much the same for those
of you who want to do split deployments
the web objects live monitoring tools
are capable of dealing with and managing
web objects for 5/1 applications and we
have some new features what are some of
the benefits of moving to web objects 5
well there's a number of them the big
one for a lot of you and I know this has
been a concern is that web objects 4 or
5 used an older version of the JDK
that's over web object 5 uses the JDK
1.3.1 actually I believe for those of
you who are on Windows you'll notice
that we do still install a 1 dot 1.8 JRE
this is purely for the use of our tools
you should not use it you should just
pretend it didn't pretend it isn't their
benefit the big thing about moving to
the JDK 1-3 is that it allows you to
integrate with a lot of the new and
third-party tools that are out there
development environments debuggers
optimizers a lot of tools that you
didn't have access to when you were
writing in the bridge java environment
and it makes it a lot easier for you to
integrate with third-party products
because as we all know there's a lot of
mindshare in the java world there's a
lot of people producing packages to do
everything from control robots to do
reporting you now have access to all of
those packages and because we've moved
to JDBC you'll also have extended
database connectivity this means that
you no longer have to wait for a
database company to come out with a set
of native client libraries on whichever
platform it is you'd like to deploy on
most database companies ship type for
database JDBC drivers which plug into
our JDBC adapter and things should work
much more easily you can do development
on Mac os10 or on Windows as you could
in 4-5-1 and we also support deployment
on those platforms plus Solaris one of
the other big features of web objects 5
is that it's much easier to develop on
one platform and then move your
application to another platform there's
no issues with remembering your LD
library path there's no dynamic shared
libraries issues things go much more
smoothly and we've had some performance
improvements
Ernie talks a little bit about this a
couple of days ago we did some
benchmarking comparing web objects 4-5-1
with web objects 5 on Windows Mac OS 10
and Solaris and lo and behold we
discovered that we did a good job of
converting to pure Java we're faster on
all platforms on Mac OS 10 we're about
22 percent faster than a comparable app
written in objective-c
pure objective-c this is not comparing
against bridge Java this is pure
objective-c
we're about 22 percent faster on Mac OS
10 or even better on Windows we're about
51 percent faster and on Solaris
platform that I know a lot of you to
play on we're over a hundred and eighty
percent faster so we were very happy
with that
you can clearly say so now that we told
you that yes there are some serious
benefits to moving to web objects 5 a
lot of you are going to have the
question should I convert or not and
people who should convert are people who
have objective-c or web script apps that
are very early in their development
phase
or people who have existing bridge Java
product projects that they may be in
deployment or they may be in development
it's very easy to port bridge Java to
pure Java and anyone who requires to
access to more Java standards or to
third-party products should also
consider moving to web objects 5 people
who should not consider or at least
should seriously can con should be
seriously contemplated about moving to
web objects 5 are people who have
objective-c projects that use a lot of
low-level objective-c if you're using
categories if you're using posers if you
have obviously message send anywhere in
your code you may want to think twice
about migrating because it means you're
doing things with the objective-c
dynamic runtime that cannot be done
easily in Java if you've got a lot of
basic C code if you're losing using lots
of third-party C libraries you're doing
a lot of nasty pointer manipulation you
may also want to think twice about it
because that's a more complicated
conversion and if you've got an app
that's already in production and it's
not being updated there is an old
engineering rule if
that I learned when I first started to
programming its if it ain't broke don't
fix it it's you're happy with your
application it's making you money you
don't need to change it by all means
don't next question once you've decided
to convert is how do you go about
converting we provide a tool called Java
converter that basically allows you to
simply and programmatically convert your
web objects application from four or
five to a pure Java environment on
Windows this is located at next root
library web objects Java applications
Java converter gua on Mac OS 10 this is
at system library web objects Java
applications Java converter gua it
claims to be adult whoa but it really
isn't we're just leveraging the
packaging you run it from a shell inside
the directory and it's a fairly simple
thing to do you enter your command
script plus the full path of the project
directory or files that you want to
convert and you hit return and we take
over from there if you want to migrate
using the Java convertor there's a few
ways you can do it if you have if you
want to convert on a file by file basis
you can take an individual C objective-c
or web script file and convert that to
pure Java or you can convert an entire
project directory at once or if you're
feeling a little bit more constrained
you have code that's possibly in the
nastier areas you may want to consider
doing a hybrid project and migrating you
know first to bridge Java on a file by
file basis and then once you have all of
those done moving up to pure Java or you
may want to move your entire project
first to bridge Java and then to pure
Java this could give those of you who
have lots of categories and posers and
that kind of thing a little bit more
time to do your conversion without
having to disrupt your application some
of the advantages of using Java
converter that we don't touch your
original source code we lay down a
parallel set of files from as the ones
we converted if there's a conversion
problem in the converter we clearly
describe the error in code in your code
in the new code as a JC error JC warning
or JC info we also print the transcript
a little warning that something happens
so you can just go off and search and
find out what the problem was
we've tested the Java converter against
most the Objective C frameworks we've
got we've tested it against woof we
tends to test it against AOF you'll
control EO access we converted many of
our examples using it we've done a bunch
of internal code that you will never see
it's extensible with customized top
scripts if there's something that you
need it to do that it doesn't already do
and it's a lot faster than manual
conversion what I can say is that when
we did before we had the Java converter
we were converting by hand and we were
managing to do about 300 350 lines a day
once we got the Java converter and
played that jumped up to 3 to 4,000
lines of code a day you can spend an
awful lot of time moving brackets around
some of the limitations though are that
we cannot convert your eel model file
you're gonna have to go in and manually
change the adapter and possibly add or
remove a little bit of data we don't
change any of the api's that you've put
in your WOD files or in any of your
other archive files and if you have
Objective C code that relies on poseurs
categories that kind of thing we cannot
fully convert it we can create helper
classes that will take the place of your
category but you're gonna have to go
through your code and in any place where
you're calling a method that was in the
category you're gonna have to redirect
it to use the helper class C code as
I've mentioned we can change the C
function invocation to a method call but
we can't translate whatever's on the
other end of the method and we can't
determine which new API you should be
hooking up to so you're gonna have to do
that by yourselves and the conversion
process does take you about 80% of the
way there though and I'm sure a lot of
you are going yeah right it can't be
that easy so I'm gonna call Francois Gio
up and he's going to convert one of the
examples that we've set before of
objects four or five one right here on
stage and front
my please hello
welcome everybody so some people know me
already I already did last your
presentation and Java converter and I
will attempt to out impossible today I
will convert here with no net to protect
me an application we are shipping well
we used to ship info file so we are the
window okay so as Melissa said Java
converter converter is a terminal based
tool and I am going to go execute it we
I have here a sink movie application I
cannot open it because it's a 4/5
application but trust me it here I'm
going to go in the product directory
here the sink movies application now in
my java applications folder i have the
java controller application and inside
that who are as Melissa said series so
the Java converter tool so to use a Java
controller tool I just make it point to
my think movies application and I have
my covers covers
go first
okay it started no I can go have a
coffee I don't have to type anything he
will generate the classes in the java
classes it will create a new project
copy everything in a new directory so
that it doesn't stomp on existing files
and that's it well I think that's it but
it's only 80% of the work is done I'm
going to do manually the last 20% so
here I have five word do most of you
know what five Margie's it's a very
powerful UI based tool and I'm going to
compare what I had originally and the
output of the converter
okay I have both of them here so you
notice that it changed quite a bit of
five but if I look at these files
there is mainly one difference and we
look at the files but there are more
differences but for example of a five
we've just one difference here all the
Derrick Andrade needed to do is to
change import statements no big deal
let's look at a more complicated file
what does this one do just some packaged
renaming here on the second change and
this one is even more complicated so
here we have the case of an API change
the Java control did for you actually
this instead of returning a component we
know return an interface and here are
some warnings that Java controller put
in for you and in this case the warnings
are not very useful because the syntax
was correct in the first place and here
there were some changes that Melissa
will talk more about later on and as
Gregorian date has been replaced by NS
timestamp and all the api's and class
names have been changed accordingly more
or less time stem changes
okay and you can trust me most of these
are just the same right
you trust okay so now the next step is
to open the new converted project in the
new product builder so I'm going to
click on import PV that project is one
of the wizard that project builder comes
with and I'm going to point it to the
converted project
are people coughing on purpose
okay so that's it I have my classes here
my components
everything is very even the frameworks
are here or here the reserve so one good
thing about conversion is that it
enables you to do a lot of cleanup
because objective-c ends up which were
really lenient you could go along and
have a lot of inconsistencies and you'll
notice that most of the changes I'm
going to go and do now are to fix
inconsistencies here there is a
framework that we didn't use that was
there listed so I'm not going to remove
it and one framework I do need to add is
JDBC adapter framework because
everything goes through JDBC now
and I'm not as good as Steve Heymann so
I'll just select all the targets here I
put it at the right place looks better
what else I have a new model and I'm
going to open it because I know I need
to do some changes in there Java
controller does not fix the models for
you
I will go and switch adapter to the JDBC
adapter you have the known adapter I
don't recommend using the known adapter
is the DVC one won't take you far
okay now here another thing that I found
that was inconsistent in this model is
that we had a lot of packages business
logic server and we never referenced
these packages anywhere in our project
so why keep and actually Java will
refuse to run your app if we keep these
packages I'm going to get rid of them
okay
now if I inspect one of these at this
point I should be able to go and fetch
it yeah
so my dad my open bill database is
running and I can look at entries I
think yes here one tricky point in the
EO model is that most of the number of
classes cannot be resolved automatically
by the JDBC adapter so here that you see
that the value type or number is set to
an intern that's correct but here for
bigdecimal we have no value type so the
this has to be fixed to the capital V
value type so this is a type in the
model is a type in Java at the end when
I run the application so class and this
is the type the intermediate type setup
by the DBC by the division at all if you
have questions about that I recommend
going to the advanced us session is
there any more of these member there is
one more
I have to find it geez the movies number
a big this you know here this one needs
to be fixed okay now I won't forget to
save it and if it opened just in case I
forgot something okay now I think I can
build let's see what kind of arrows I
get
okay I have some more of these packages
laying around in some places that's a
side effect of this okay
another one
so I'm just walking through it like you
would if your developer
so I will know the app compiled so I'm
not starting the application from
Project danger and it will stop Internet
Explorer
okay so here I add an arrow and I'm
going to go try and figure out what's
wrong it's saying that it was not able
to to create the page me I can close
this one let me go to the terminal so
when you cannot create the main page it
means it's pretty bad and I know where
it is if you remember in during the
final conversion the when I did the a
used file merge there was a change done
here on this line and Java converter is
clever enough to recognize an
application and to insert a main
function so that the application can be
started except here it was not able to
recognize it because it there was a
complete package specified it was not
clever enough to recognize that this is
actually what occasion so I need to add
this main function is all by hand
so all these main faction does is for
web so call the main code to your own
main function I will say I can stop that
and recombine
so the app will come back somewhere
okay no I have the first page it seems
to work okay
I mean oh I hate this movie no I won't
enter review but I still hate it
let's let's add a test see if the
features
okay so there is another problem it is
to be expected and the problem is in
this new nsdictionary here and the page
is what page was this a display video
page so let's look at this play video
page okay
so this play video page doesn't have an
image dictionary but takes a mutable
dictionary so I'm just going to go fix
that and that will be it once again I
don't know how the bridge could live
with this frankly but I'm sure Java
doesn't take it
I go back to the head and see the
Russian works
yeah you tended it they're actually an
old one there too okay so that that's
about all it takes so as you see 80% of
the work was done the last 20%
interesting part was left to you on most
of what we did was cleaning up an
imperfect model on an imperfect
application in the first place
so as you all right perfect code you
should have much less problems than we
do even in your examples if I find me I
will just do one last thing and open up
again the window where I did the
conversion and if I just type Java
controller I see the set of parameters
that can be passed to it you have a flag
to stop the conversion at bridge java
application so if you're converting from
objective-c to bridge diver you can do
that with this flag you have a flag when
you are using Objective C conversion to
specify extra headers to resolve macros
and so on you can also give special
instruction to the free compiler and you
can specify your product directory and
Objective C file a bridge Java file or a
web script sign and then there is a
description of all the other flags so
one point I want to make that Melissa
didn't is that bridge traffic conversion
will only work on Windows and T because
as you know web objects 5 does not run
bridge to have applications and web
objects 4 5 on Mac OS 10 doesn't burn
any bridges other application either so
while you're on windows NT you can use
Microsoft converter from Java to see
shop and you get a 64 percent conversion
to see shop
same that will be it and you back the
mic to Melissa thanks Francois so as you
can see most of the problems you're
going to run across in doing conversion
of applications or well many of them are
you going to be your own fault
now you're going to talk about what
you're gonna see in your code after
conversions happens you take the Java
converter you run it and as Francois
showed you we do some stuff to your
original code there's two general
classes of things you'll see afterwards
there's stuff we've put in specifically
to help with conversion and there's
stuff that is new in our frameworks and
is intended to be ongoing we've added
some convenience classes to help you
port your code to pure Java NS
comparator and s bundle low timer these
are things that often have equivalents
that you could write Java code to do
what they do but we figured we'd save
you the trouble we've left some classes
like NS coder and NS coding in although
they're now completely abstract we
removed a few things NS run loops NS
user defaults and we changed the
validation mechanism to be more in line
with the way Java works NS comparators a
pretty simple class that encapsulates NS
comparison results from objective-c we
only use it in a couple of places we use
it in nsarray sort using comparator
method and it basically sorts the
elements of the receiving array into a
new array we use it in the NS mutable
arrays.sort using comparator method
which sorts in place the elements of the
array if you're writing new java code
you may want to consider making any
classes that you're going to be sorting
comparable this will have sort of two
things comparable isn't an exact match
to NS comparator but it does allow you
excuse me to create a one really simple
comparator to use in these things that
simply defers to the comparable methods
on your underlying objects NS bundle is
going to be pretty familiar to those of
you who worked with the objective-c it's
corresponds to the directory where
related resources are stored it still
has some deprecated
api's to help can with people who are
converting from four or five and we've
extended the functionality to handle
properties files and do we have some new
api's for finding and loading resources
for those of you who are using it in
four or five you should note that the
java class loader does not support the
concept of dynamic class loading so
there is no concept of loadable bundles
in level objects five we've renamed and
deleted some stuff most of it shouldn't
worry you very much but just so you know
that it happened we renamed NS timer to
what timer and we don't use it for
session timeouts anymore NS run loop has
been removed we have for those of you
who get into D compiling code we have a
private will run loop that we use in
what for wool application specific stuff
but you should not be trying to use it
and we've removed NS archiver which was
the NS concrete the concrete subclass of
NS coding coder will talk a little bit
more about that when we talk about
serialization later user defaults is one
thing that took a fairly serious hit
we've actually deprecated the user
defaults class itself although the sort
of concept of defaults exists in class
NS properties that we'll also talk about
later some of the default names now
property names have been deprecated whoa
debugging enabled yo adapter debugging
enabled NS project search paths they're
still there but they do different things
and they may not be there for long and
some defaults have been renamed whoa CGI
adapter URL is now what would after URL
and whoa should send like beat is now
lowlife beat enables we'll talk more
about properties and what they've become
later and we had to change the
validation mechanism to review for those
of you who have had four or five but you
know you wrote those methods a long time
ago validation methods in four or five
took a pointer to the target object as
their parameter they returned an
exception object if for some reason the
target object was invalid and if
coercion was necessary that would happen
is a side effect on the target object
well having side effects on target
objects that are passed in as parameters
isn't something that Java is really good
at a lot of Java's value classes are
final and immutable so we had to change
that so
validation methods in four five once
again they take the object as their
parameter but instead of acting by side
effect they return the valid value for
that parameter as the return value and
if for some reason that parameter value
was invalid they throw an NS validation
validation exception if they do return
null that should be interpreted as
coercion to the null value in Java
note that the Java converter doesn't
take care of this for you you're going
to have to go through and look at your
validation methods and figure out what
they really should be returning here's
some examples of method signatures in
Objective C for five Java and five Java
the first one is pretty simple
it's a validate street address it takes
a pointer to a string and you can see
that it returns an NS exception for five
Java looks very similar because we're
going through Java wrapper is to get
actually use Objective C classes
underlying the Java again we pass in a
string which is down there in the bridge
interpreted as an NS string which can be
mutable if it needs to be and we return
a void or we don't return anything I
suppose would be a better way to put it
that would be that one and the final one
is the correct way to do this in web
objects five again you see that we're
taking a string parameter value but also
see that instead of returning a void we
now return a string and throw a
validation exception that's pretty much
all there is to it
and now on to the new and interesting
stuff we're engineers we don't need to
link we don't know when to leave well
enough alone we have to constantly add
new stuff to our products or we get you
know unhappy so we've added some new
stuff we've added a bunch of time
classes and s times down Bennis
timestamp formatter and it's time zone
we've added in a socket utilities to
help you creating saw to help you with
creating sockets we created a new class
called NS log and as I mentioned earlier
NS properties we've done some stuff with
NS locking which some of you may be
familiar with
we've changed key value coding around a
little bit and we've moved to Java
serialization we've also done some stuff
in other you know less central web
objects packages like we'll mail
delivery whoa smile and Java plot
why honest times down this is a question
that we've had several times already at
this conference we've had it from people
who saw the beta we've had it from
people who you know immediately download
installed the web objects developed her
stuff from the CD you got we wanted to
basically give you all of the
functionality that was in an esper glory
and date in our web objects 5 product
and we ran into some issues in the JDK
first off there for those of you who've
looked at it you know that their time
zone class does not contain historical
information and as we were trying to
implement that we ran into some other
assumption conflicts with the way we
were implementing time zone and the way
their date classes worked so we needed
to create a time class to work with our
time zones why didn't we call it NS
calendar date or anise coriander
no great deep reason we wanted to show
that it was descending from Java SQL
timestamp and to a certain extent the
word calendar is already in use in Java
and given it our time stamps don't work
at all in the same way we didn't want to
introduce any possible confusion one
thing to remember is that you really
shouldn't use our stuff with their stuff
it doesn't work too well you will see
weird behavior in s timestamp as I said
is the so class of just in Java SQL
timestamp it replaces all uses of NS
calendar date or for those of you in the
bridge Java world and it's Gregorian
date it provides most of the same
functionality that you saw in four or
five or four five one and yo f Maps
database date types in two NS timestamps
something that has changed noticeably
that if may effect a few of you is that
we have a new reference date we've moved
from January 1 2000 UTC which was the
objective-c sort of time 0 to January 1
1970 UTC which is the Java and UNIX
standard time 0 we've also added a
timestamp for matter too well format
timestamps so class of Java text format
it doesn't really do much although one
thing that you might be pleased to hear
is that it's capable of dealing with
Objective C pattern specifiers as well
as java pattern specifiers and it's a
little bit heavy weight so if you've got
an application that does that formats
timezone or time stamps into strings in
a number of places you may want to
consider creating one timestamp
formatter and sharing it amongst all the
stuff we've created NS timezone as I
mentioned earlier this kit allows you to
have a correct historical and
geographical context for your time it's
a subclass of java.util timezone it's
built using the standard zone info files
that you get from by FTP from LC NCI
nih.gov this basically lets you and
there will be a till about this later
you can if those files change you can
download the new versions compile them
and drop them into web objects to get
the new zone info and it should only be
used as I mentioned can't reiterate
enough with our time classes don't try
and mix in that trip Java and a socket
utilities is a fairly simple class that
we added to let you specify connection
timeouts and if socket creation fails it
will throw a timeout except it will
throw an ioexception
without the utilities there can be a
problem on some platforms where failing
to create a socket will hang your system
indefinitely and we kind of thought that
was a bad idea it's fairly simple to use
an S socket utilities here's an example
of how you'd create a socket using the
standard Java way so you've got your
constructor taking an address support a
local address in the local part this is
the equivalent in using in a socket
utilities there's a factory method that
takes an address support a local address
a local port and a connection timeout it
measured in milliseconds and notice that
we catch the exception which means
there's no socket and we have to deal
with that somehow in its properties as I
mentioned earlier replaces
nsuserdefaults
it's basically a wrapper to the standard
Java properties mechanism which you can
see defined in Java util properties it's
a convenience class for merging
application properties of standard
system properties with framework
properties and all that kind of lovely
stuff for convention conversion people
who are converting a lot of the methods
that were on nsuserdefaults are still
around on NS properties what are
properties where properties properties
can be read from a number of sources
there's a set of standard system
properties that come with your VM
there's user specific properties store
it in hot Java properties your
application your frameworks can have
their own properties files your
application has can have
properties file and you can specify them
on the command line we use the standard
Java conflict resolution mechanism which
states that the last property red is the
one that gets used there red in this
order it's worth knowing more details
properties files must be named
properties and they must be located in
the resources directory of your
framework or your application they're in
the standard Java properties format
which is that they're in a file each
property is a on its own line each line
has the format property key equals
property value with no spaces around the
equal sign if you want to specify the
properties on the command line you use
the standard Java dash D flag although
we do also in a deprecated fashion
support the old objective-c format for
command line arguments NSLog I mentioned
this is a class that we're actually
pretty excited about we think it's neat
we think it should be very useful to
most of you
there's actually three classes involved
there's NSLog which is a static class
that allows you to interface with the
web objects logging system there's
logger which is an abstract class that
defines sort of the core functionality
in which you should subclass if you want
to do your own logging mechanism and we
provide one concrete subclass the print
stream logger which will basically while
your output to a print stream why do you
want to use it well there's a few
reasons it's set up to allow you to
control the scope and granularity of
debugging you can set up debug groups
and debug levels which will allow you to
say if you have an application that does
HTML generation has business logic and
has database access you can separate by
debug groups logging in each of those
areas and you can turn only one of them
on it's time if you want or you can use
debug levels to say well I'm in
development but I don't want to have to
worry about touching my code when I go
out of development so I want all of this
logging to happen at one debug level but
once I move into deployment I want to
set a different debug level and only see
really critical stuff you can redirect
the output however you want by
sub-classing logger we provide the print
stream you can set it up to do email or
anything else you really want if you
decide that you want to turn on for both
logging it will also print out the
time stamp at which the logging happened
and the thread that did the logging this
can be useful if you're trying to track
down synchronization problems and
there's an issue known issue with Java
Runtime exact which is that if you
launch a child process using exec and
then don't pull data out of the child
processes out and error streams then
your child process will eventually hang
when its buffers get full again we don't
think freezing is good here's a sample
how to create a debug group it's pretty
simple and you'll notice that it's a
long and that we're left shifting by 40
the first 32 bits are in use by internal
web objects logging stuff the other 32
or open for you to use however you'd
like to base this the second bit is an
example of how you would pass in a
command line parameter to enable
debugging
there's your command line basically you
read in the property standard Java this
is how you read properties mechanism if
it says you should be debugging then
we're both enable the verbose debugging
on the debug out and error streams
enable debugging for the group that we
defined earlier and set the local level
to informational this will print out
everything in that debug group it's
pretty simple to redirect the output to
a different directory again you pass
something in in the standard Java
properties format again you read a
standard Java system property if their
property is there create a print stream
pointing at that file and set as
appropriate here we show setting in a
slug debug you can also set NS log out
in NS log error if you want you can set
that to no and no logging will happen at
all
hi my name is Rd Wilhoit I just want to
get this out of the way to begin with
I'm not female and I'm not French but I
am a web objects engineer so it does
sometimes happen today I'm going to be
telling you about a different manner of
interacting with the web objects
application server as Melissa alluded I
will be talking about NS log I'm also
going to be talking about the world mail
delivery class which is not new to web
objects 5 but has been revised slightly
now it uses the SMTP client class in
Suns standard class libraries I'm going
to show you two different forms of email
integration the first thing that I'm
going to show you is sending of web
objects components to a hypothetical
customer the second thing that I'm going
to show you is a sending of critical
error messages to a hypothetical system
administrator for demonstration
convenience I'm going to be using the
same email address for both the customer
and the system administrator obviously
this wouldn't be the case in real life
but I only have one web browser here and
I'm sorry one mail browser here also in
order to clarify the demonstration my
application copies some of the images
from the think movies example but it
isn't actually the think movies example
it's just a partial mock-up I'm not sure
if we're going to be able to make the
source code for the demonstration
available but I didn't want to confuse
you if you do have a chance to look at
the source code as many of you may know
the low mail delivery class is capable
of emailing web objects components as
well as plain text messages you can use
this as an alternative mechanism for
interacting with the web application
server let's take a look at our at our
project we are going to be looking at
the application class and more
specifically at the constructor for the
application class one of the most
interesting things that's happening in
the constructor which is going to be
invoked at startup time so we're going
to magically see an email appear in our
mail browser is that we're invoking a
direct action called send email form
action if we go and look at this direct
action
we see that it's very simple it really
only does one thing compose component
email so we're going to be sending an
email using page component called email
form to a pre-specified recipient I'm
not going to show you the source for the
page component you'll see the source the
results of the source when I launch this
thing so let's fire it up and see what
happens
as this thing starts up I wanted to
mention that I'm doing some of the
configuration on the sly of the SMTP
host used by will mail delivery as well
as the recipient and the sender and all
that stuff using command-line arguments
in project builders launch panel so
that's that's how it's finding out all
of this information so it started let's
go and look at our mail browser and we
see that our friendly web objects
application has sent us an email and
this is a list of movies that we can
rent each movie is represented by a
hyperlink I'll choose my favorite one I
know if any of you can guess which one
that is
for some reason ie wants to insert
itself I don't know I think Microsoft is
wanting to get on stage with me but
anyway I'm gonna go back to the project
to show you what's happening behind the
scenes before we see what happens
what the result of clicking on hyperlink
is so if we go and we look at the direct
action class again clicking on the
hyperlink actually invokes a second
direct action called rent selected movie
action and this action does two things
the first thing that it does is that it
sends a confirmation email to our
hypothetical customer this is
essentially the same thing that we've
just done so that's not specially
interesting the second and more
interesting thing that we do is that we
do a bit of Investigation as to what
what movie we've got and we see that the
application has come back to us and it's
it's given us the confirmation email but
oh we've received a system error so this
is intended obviously for the system
administrator not the customer it's no
atrocious cinema alert apparently the
apparently the web objects application
doesn't like my choice at movies so
going back to the project let's see if
we can answer the question how's this
email being sent so we saw here that
we're looking we're actually checking
what what movie were selecting this
thing isn't emailing it every time I
don't have anything behind the behind
the magic curtains here all that is
doing is is invoking the append Len
method of the error member of the NS log
class and you can see that it's just
passing a string and the string I happen
to use HTML because it looks nicer in
the mail browser because we have nice
HTML rendering and mail done app but you
could you could do any string obviously
it doesn't have to be HTML but the real
question is how is the email being
generated this not really clear here
because as Melissa mentioned our default
loggers which are the print stream
loggers a few things to the console as
well as to specified files so what's
happening here what happens is that the
logger class is actually an abstract
class as she mentioned and you can
subclass it as a matter of fact you can
insert this thing into the NS log class
which is the is the broker for all of
the logging interactions you see here in
the declaration that we're extending NS
logs logger inner class and if you look
at the class initialization you see that
we are initializing all this stuff using
those command line arguments that I
mentioned before we create a new
instance of the male logger class and we
set the error member of NS log using
this new instance which you saw before
the local variable is called air that's
the male logger instance so
unfortunately this doesn't really tell
us how the email is being sent to
understand that we need to go and look
at the append method there's a lot of
code here this this example is is
complete it's a simple example but it is
a complete example we're not going to be
talking about all of the accessor
methods and all the rest that's as but
as you can see here and it's hard to see
with a big font but I'm actually
the appending method now there's an
abstract method I've implemented it here
but instead of using print streams I'm
using the SMTP client class in order to
email the messages so I've already
mentioned why how this is different from
the default logger why you care about
this is that in Java still it it's still
useful to log things a lot of times and
unfortunately is still necessary the
debuggers are can be pretty decent but
sometimes is unavoidable when debugging
things to to log things to understand
what's happening one of the nice things
about this is that you can use the
default print stream loggers which is
really just equivalent to
system.out.print 'ln and is just as easy
to use you get all the same capabilities
but you don't have the problems that
Melissa alluded to and you also don't
have to comment the things out and
recompile you can just leave it in there
and you can turn off the loggers you can
even configure that at runtime so using
the some command line arguments I'll
refer you to the documentation for more
information on those command-line
arguments so this is just a
demonstration of one of the new features
and it's log in web objects 5 but I hope
that this demonstration encourages you
to take a look at the whole product
thank you for your time ok thanks well
onto more stuff that was interesting and
fun and I've still got less interesting
stuff to deal with so please bear with
me
ans lock this should be familiar to a
lot of you who were working with
objective-c there's three classes in s
lock and it's multi reader locked in s
recursive lot they all conform to the NS
locking interface this basically says
that thou shalt implement the methods
lock and unlock mostly they're here to
facilitate conversion from web objects
for 5 but they also are a little bit
more complicated and a little bit
broader than the Java synchronization
mechanism so they can coordinate locking
of objects over a longer period or over
a more convoluted code path and they can
allow developers to do things that are
kind of hard to do using just
synchronized
good example of that would be the multi
reader lock Java synchronization method
doesn't distinguish between reading or
writing so it always watched the object
that you're looking at but if you're
writing your application you may know
that you know 90
nine point nine percent of the time it's
gonna be a read so it doesn't really
matter if multiple things are looking at
the data at the same time so you may
want to use a multi reader lock which
will end up only locking the object when
you're trying to write to it key value
coding a lot of you are probably gonna
recognize that name from previous
versions a unified way to access
properties of different types it can
access things that are in methods
private methods public methods instance
variables NS key value coding is yoki
value coding split up into a number of
pieces there's four abstract interfaces
that define the various methods and key
value coding there's an error handling
interface and there are some default
implementations that we provide the
first interface is generic NS key value
coding this is the very basic if you
want key value coding behavior you must
implement this interface defines key
value for key and take value for key it
has a subclass NS key-value coding
additions which implement some value for
key path and take value for key path the
methods stored value for key path and
take stored value for key were defined
and split out into a Oh key value coding
again that's the subclass of NS key
value coding and finally there's yo key
value coding additions which implement
defines the methods values for keys and
take values from dictionary this
basically allows you to implement
whichever pieces of the key value coding
stuff you think you're going to need in
your application without having to
implement any of the rest of it in each
interface we define two static inner
classes there's the default
implementation which is a convenient way
to get it the default behavior if you
want to add key value coding to a class
and there's a utility class which is a
convenient way to get the default key
value coding behavior for any class
whether or not it implements the key
value coding interface as I mentioned
earlier we've gone to Java serialization
NS code and NS coding have our abstract
now and we've replaced the whole the
we've replaced our use of them with a
native Java serialization scheme we've
left them in place in case you had
subclasses of and as our coding that you
wanted
continue using any classes that
implemented NS coding now are now
implementing serial are now serializable
in java and if you want to see an
example of how Java serialization works
have a look at the persistent session
stories apple that we shipped with web
objects 5 what are the advantages of
doing this Java developers don't have to
lose learn a new archiving scheme which
is a good thing and the Java Runtime
framework does all of the work it takes
care of graph traversal it takes care of
cycle analysis all of that stuff we
don't have to worry about it anymore we
can concentrate on making web objects
better well mail delivery as RD was
talking about earlier is based on Suns
Sun net SMTP SMTP client this is a
protocol that doesn't support cc or BCC
so people who are cc'd will also end up
in the to field but it does allow mail
pages to submit forms or to CM pitchers
because well absolute URLs have
generated java plot some of you may
recognize this from previous versions
it's now a WT based which means that all
a WT fonts are available and that images
are anti aliased there's been a number
of bug fixes and some improvements
unfortunately it's now subject to the
limitations the AWT which is essentially
that if you want to use it you have to
have a window server running this is a
limitation that should vanish when 1.4
is released later this year and the wolf
smile framework some of you may remember
that we demonstrated this at web at
[Music]
www.flairsgymnastics.com
but when various pieces of it start
playing if you have streamed content and
I think we're done
in summary web objects five is pretty
much the same as web objects for five
and four five one we haven't changed an
awful lot we've added a few things we
provide Java converter to help you
migrate and we've added some new stuff
to encourage you to move from four five
to web objects five I think that's all I
have to say unfortunately I can't play
guitars and I don't sing very well so
you know I can't live up to James James
Dempsey's yesterday and I think I'd like
to call my QA team actually I think
first I had supposed to mention the lab
and it's open until 6:00 most days this
week and supposed to encourage you to
vote for what objects is the best app
server here's some of the other things
that you might be interested in some
things that have changed between web
objects five four five and web objects
five there's a direct direct to Java
client XML later this afternoon and
deployment has changed a bit and if you
have feedback and I'm sure you will
there's the feedback forum on Friday and
list of people to contact there's Tony
our who's our director Bob Fraser Fraser
our marketer because I services lots the
URLs up there
you