A newbie question

[Alberto Salvati]

Hi, All.
I'm Alberto.
I'm working in Borland delphi since 1997 and now I'm using MsVisual
studio 2005, too.
I ask you to get information about path to learn java EE.
But don't need info about OOP... I'm using Borland delphi as OOP and
msc#.
So, I DON'T NEED info about interfaces, classes, inheritance, and so
on.

I want to understand how I can build a distribuited application
component based using jee.
In delphi I use COM/DCOM. In msc# I use Remoting/MCF.
I've developed and used web service in delphi.
And I've developer a ppc application with .Net cf 2.0 that uses http
requests to send data to a web server.

*Maybe*, I need to learn something about Web Services in Java....

I'm searching someone as a tutor in my country, but ad this moment
I've not found anyone...
Many people use Java but I don't know anyone that KNOWS java......

So, I try to find some book about jee, but I dont see a book for me...
Ehm.. Today, I don't vahe money to pay sun training....

TIA per any help suggestion and so on.

AS

 

[Tom Anderson]

I want to understand how I can build a distribuited application
component based using jee. In delphi I use COM/DCOM. In msc# I use
Remoting/MCF. I've developed and used web service in delphi. And I've
developer a ppc application with .Net cf 2.0 that uses http requests to
send data to a web server.

The java equivalent of DCOM and remoting is RMI:

http://java.sun.com/javase/technologies/core/basic/rmi/whitepaper/index.jsp
http://java.sun.com/javase/6/docs/technotes/guides/rmi/index.html
http://java.sun.com/developer/onlineTraining/rmi/

J2EE uses RMI for communication; however, if you write a J2EE component
(an EJB), you don't need to worry about RMI directly, because the
container takes care of most of the details. I'm afraid i don't know of a
good and up-to-date online tutorial about EJB, though.

tom

 

[Arne Vajhøj]

I want to understand how I can build a distribuited application
component based using jee.
In delphi I use COM/DCOM. In msc# I use Remoting/MCF.
I've developed and used web service in delphi.
And I've developer a ppc application with .Net cf 2.0 that uses http
requests to send data to a web server.

COM ~ Java Bean
DCOM ~ EJB
Remoting ~ RMI
WCF ~ JAXWS or EJB or RMI or JMS depending on WCF config

Arne

 

[Arne Vajhøj]

The java equivalent of DCOM and remoting is RMI:

I would consider EJB to be the equivalent of DCOM due to the transaction
and security support in DCOM.

Arne

 

[vk02720]

I would consider EJB to be the equivalent of DCOM due to the transaction
and security support in DCOM.

Arne

Some comparison between Java and Microsoft .Net
http://kaushalp.blogspot.com/2005/08/comparison-between-j2ee-and-net.html
http://www.informit.com/guides/content.aspx?g=dotnet&seqNum=102

 

[Arne Vajhøj]

Some comparison between Java and Microsoft .Net
http://kaushalp.blogspot.com/2005/08/comparison-between-j2ee-and-net.html
http://www.informit.com/guides/content.aspx?g=dotnet&seqNum=102

The first looks like typical blog-spam. I will not even
comment on that.

The second one is very pro-.NET and I think the author
would benefit from learning a bit more about Java.

<q>
The Java Virtual Machine was designed to execute Java code and although
there have been attempts to port other languages to the JVM, those
efforts have not been widely accepted or completely successful.
</q>

I would say that the other languages in Java are about as
widely accepted as the .NET languages besides C# and VB.NET.

<q>
The built-in Java classes are typically very simple and developers often
build their own frameworks on top of them, or have to find third-party
frameworks.
</q>

I would not call the Java library for simple.

And I know that people develop frameworks in .NET as well - NHibernate,
log4net, NUnit, NAnt, Spring.NET etc..

<q>
The .NET Web Forms classes provide a much richer environment than either
of the two competing Java forms packages (AWT – Abstract Windowing
Toolkit, or Swing).
</q>

????

He probably meant Win Forms.

<q>
Because the Java framework is limited in scope and richness, developers
often use proprietary classes to access features available to the target
platform.
</q>

It happen that Java apps do platform specific stuff via JNI. It
practically never happen that Java apps uses platform specific
classes in pure Java.

<q>
Because lingering incompatibilities between the various Java
implementations have continued to plague true cross-platform efforts
</q>

Those are also practically non-existing.

There are a TCK to ensure implementations compatibility.

<q>
Security is richer in .NET. Along with APIs for cryptography, secure
cookies, and authentication, there is also a rich and extensible
mechanism for assigning different levels of permissions to different
sets of users, based on where the code came from. For example, you can
mark all code from a particular vendor as safe. All code from a specific
URL can be granted (or denied) read/write access to specific resources
such as the temp directory or screen. In addition, applications can be
marked as requiring certain permissions (for example, requires access to
the file system). If these permissions are not available, then the
application will not load. Because the security check is performed at
load time, the developer is freed from writing security fail detection
logic throughout the application. This is managed through a new
technology called "code access security," which works for code loaded
from either the Internet or the local machine.
</q>

Java does that.

I guess he has never set a SecurityManager in Java.

<q>
For example, with ADO.NET disconnected data access, more data functions
can be completed in-memory, which in Java Database Connectivity (JDBC)
require a round trip to the database.
</q>

He need to check up on javax.sql.rowset.CachedRowSet ...

Arne

 

[vk02720]

The first looks like typical blog-spam. I will not even
comment on that.

The second one is very pro-.NET and I think the author
would benefit from learning a bit more about Java.

<q>
The Java Virtual Machine was designed to execute Java code and although
there have been attempts to port other languages to the JVM, those
efforts have not been widely accepted or completely successful.
</q>

I would say that the other languages in Java are about as
widely accepted as the .NET languages besides C# and VB.NET.

<q>
The built-in Java classes are typically very simple and developers often
build their own frameworks on top of them, or have to find third-party
frameworks.
</q>

I would not call the Java library for simple.

And I know that people develop frameworks in .NET as well - NHibernate,
log4net, NUnit, NAnt, Spring.NET etc..  

<q>
The .NET Web Forms classes provide a much richer environment than either
of the two competing Java forms packages (AWT – Abstract Windowing
Toolkit, or Swing).
</q>

????

He probably meant Win Forms.

<q>
Because the Java framework is limited in scope and richness, developers
often use proprietary classes to access features available to the target
platform.
</q>

It happen that Java apps do platform specific stuff via JNI. It
practically never happen that Java apps uses platform specific
classes in pure Java.

<q>
Because lingering incompatibilities between the various Java
implementations have continued to plague true cross-platform efforts
</q>

Those are also practically non-existing.

There are a TCK to ensure implementations compatibility.

<q>
Security is richer in .NET. Along with APIs for cryptography, secure
cookies, and authentication, there is also a rich and extensible
mechanism for assigning different levels of permissions to different
sets of users, based on where the code came from. For example, you can
mark all code from a particular vendor as safe. All code from a specific
URL can be granted (or denied) read/write access to specific resources
such as the temp directory or screen. In addition, applications can be
marked as requiring certain permissions (for example, requires access to
the file system). If these permissions are not available, then the
application will not load. Because the security check is performed at
load time, the developer is freed from writing security fail detection
logic throughout the application. This is managed through a new
technology called "code access security," which works for code loaded
from either the Internet or the local machine.
</q>

Java does that.

I guess he has never set a SecurityManager in Java.

<q>
For example, with ADO.NET disconnected data access, more data functions
can be completed in-memory, which in Java Database Connectivity (JDBC)
require a round trip to the database.
</q>

He need to check up on javax.sql.rowset.CachedRowSet ...

Arne

Just realized it is a bit old as well - maybe in 2005 other JVM
languages like Scala/Groovy were very new and not particularly as
popular as now. Did not like the way he makes very general statements
"Because the Java framework is limited in scope and richness" or
"Where .NET outshines Java is in the ability to fine-tune application
behavior and performance.", " In addition, the .NET application
architecture is designed to be faster." without backing them up with
any specifics.

Anyway, not a good reference for someone trying to get into Java!

Maybe, the poster may find the following useful - this looks very old
as well but provides a comparison of EJB to MTS and DCOM to CORBA and
RMI.
http://gsraj.tripod.com/misc/ejbmts/ejbmtscomp.html
http://gsraj.tripod.com/misc/compare.html

 

[Tom Anderson]

I would consider EJB to be the equivalent of DCOM due to the transaction
and security support in DCOM.

I stand corrected, thanks.

tom

 

[Arne Vajhøj]

Maybe, the poster may find the following useful - this looks very old
as well but provides a comparison of EJB to MTS and DCOM to CORBA and
RMI.
http://gsraj.tripod.com/misc/ejbmts/ejbmtscomp.html
http://gsraj.tripod.com/misc/compare.html

Very old indeed.

It uses MS Java for COM. MTS became replaced by/renamed to
COM+ with Windows 2000.

But still a very interesting article.

Arne