Difference between J2SE and J2EE...

Hi all. I was wondering what the difference between J2SE and J2EE were. I mean in the code structure. Are the packages the same, like Swing, IO, things like that. I'm a bit of a beginner in Java, only been messing around with it for about 6 months now kind of in my spare time, and I know I'm in now way ready for J2EE, but it's something I think I'd like to maybe look into. I know it's for Enterprise Applications, much bigger scale than I'm used to, but fundamentally, how is it different? Different coding conventions? New packages not in J2SE? I hope what I want is coming across okay. Thanks for all the input.
James

J2EE defines a large number of specifications, in addition to J2SE. Examples are the Servlet, JSP, JMS, and EJB specifications. Most of those specifications are designed to have implementations running inside an Application Server. There are free implementations available such as JBoss (combined with for example Tomcat), and I think youre best bet to learn is to download one of those and go from there. Servlets and JSP are a good beginning, and then maybe move on to EJB and the rest.
Br - J

Similar Messages

What is the difference between JDK and J2ee

Could someone explain, in simple terms, what is the difference between JDK and J2ee. I am trying to understand the difference.
THanks

Could someone explain, in simple terms, what is the
difference between JDK and J2ee. I am trying to
understand the difference.You can practice on this one first. What's the difference between chalk and cheese? No just kidding.
A JDK is a set of tools for Java development including compiler, runtime system and standard libraries. J2EE is the enterprise version of the Java technology platform (it's one of three). To use it you download the proper JDK's.

BACK button difference between Weblogic and J2EE server

          Hi Everyone,
          I have a J2EE application implemented mainly with JSP and EJB, which can run on
          both J2EE and Weblogic Servers seperately. When running on either of them, the
          server acts as both a web and application server.
          It is my understanding that it first goes to the cache in the browser when you
          try to revisit the previous page (JSP files) by clicking the BACK button in the
          browser. If the page is there, it just displays that page from the cache. If not,
          it will go to the server to retrive (execute) that page.
          When I run my application over J2EE server and try to visit the previous page
          by using the BACK button in the browser, it does this way correctly. But when
          I run my
          application over Weblogic server, it always goes to the server and execute the
          JSP file again in the server, rather than simply retriving that page from the
          cache. If your JSP file is simply doing data retriving, that is fine. But if it
          is doing data inserting, it will insert your data again. This is not good.
          I know that the Weblogic server is mainly an application server. But I am not
          sure when it acts as a web server,
          why it works differently from J2EE which also can acts as both an pplication and
          a web server. Does anyone have any ideas or suggestions about this?
          Thanks a lot.
          -John


I believe that the correct behaviour is to rerun the .jsp page unless the
          user specifically sets the header to allow the browser to cache it. That
          being said... You should never make a web application that can be broken by
          the user hitting "reload" or the browser automatically retrying. An
          application like this is very fragile and will probably break in practice.
          I suggest that you either make all your pages idempotent or you keep track
          through a hidden form field a transaction id and only allow the execution of
          any particular transaction once. As far as WebLogic not being a good web
          server, I would say that with 6.1 you get most of the management advantages
          of using a separate web server and also most of the static file performance
          you will find with apache or IIS.
          Sam
          "John Wang" <[email protected]> wrote in message
          news:[email protected]...
          >
          > Hi Bruno,
          >
          > Thank you for your prompt reply.
          >
          > I think I might not explain my problem clearly. My application
          > is in developing stage now. So we are just working on a single
          > serevr which can acts as both a web and an application server.
          > Later we are going to distribute our application into a web and an
          application
          > seperately.
          >
          > As you said, it seems that my problem is because the weblogic server is
          mainly
          > an application server and does not act as a web server very well. So if I
          distribute
          > my application into both a web and an application servers, it should be
          fine,
          > since it is ok when I run it over the J2EE server. Is this correct?
          >
          > In other words, I can say that the J2EE server is configured better in its
          role
          > as a web server than the weblogic server, isn't it?
          >
          > In addition, all my JSP files are only dealing with catching
          > data from user input and displaying data. Data inserting is done
          > by EJB and JavaBeans through the JSP files. Because those JavaBeans in the
          JSP
          > files, each time when I use the BACK button, it will invoke those
          JavaBeans and
          > EJBs through the JSP files and do things like inserting in the background.
          That
          > is what I mean in my previous message.
          >
          > Thanks.
          >
          > -John
          >
          > "Bruno" <[email protected]> wrote:
          > >
          > >Hi John,
          > >
          > >You should use a real Web Server on the front side of your application.
          > >Weblogic
          > >is mainly an application server that has to be used in middle tier. But
          > >it's not
          > >a good Web Server. Like almost all J2EE application. You should use a
          > >separate
          > >web server like apache, optimised to serve static file. Furthemore, this
          > >approach
          > >will enable you to physically separate the two servers for a better
          security.
          > >Anyway, usually jsp files are dynamic files and are not intended to be
          > >totally
          > >cached (except in special cases). I think you should just use JSP to
          > >display data.
          > >If you want to do data inserting, you should use EJB or JavaBeans for
          > >that rather
          > >than JSP.
          > >
          > >Hope it helps
          > >
          > >Regards
          > >
          > >"John Wang" <[email protected]> wrote:
          > >>
          > >>Hi Everyone,
          > >>
          > >>I have a J2EE application implemented mainly with JSP and EJB, which
          > >>can run on
          > >>both J2EE and Weblogic Servers seperately. When running on either of
          > >>them, the
          > >>server acts as both a web and application server.
          > >>
          > >>It is my understanding that it first goes to the cache in the browser
          > >>when you
          > >>try to revisit the previous page (JSP files) by clicking the BACK button
          > >>in the
          > >>browser. If the page is there, it just displays that page from the
          cache.
          > >>If not,
          > >>it will go to the server to retrive (execute) that page.
          > >>
          > >>When I run my application over J2EE server and try to visit the previous
          > >>page
          > >>by using the BACK button in the browser, it does this way correctly.
          > >>But when
          > >>I run my
          > >>application over Weblogic server, it always goes to the server and
          execute
          > >>the
          > >>JSP file again in the server, rather than simply retriving that page
          > >>from the
          > >>cache. If your JSP file is simply doing data retriving, that is fine.
          > >>But if it
          > >>is doing data inserting, it will insert your data again. This is not
          > >>good.
          > >>
          > >>I know that the Weblogic server is mainly an application server. But
          > >>I am not
          > >>sure when it acts as a web server,
          > >>why it works differently from J2EE which also can acts as both an
          pplication
          > >>and
          > >>a web server. Does anyone have any ideas or suggestions about this?
          > >>
          > >>Thanks a lot.
          > >>
          > >>-John
          > >>
          > >
          >

J2SE and J2EE

what are the differences of J2SE and J2EE in terms of programming? I have used J2SE in developing java applets and standalone applications and now, I want to explore more with J2EE. I am reading articles and site regarding J2EE. But for you what is J2EE all about?.
Thanks!

To be frank, if you have to ask you don't need it. Learn most of what Java SE has and can do; then you'll have a sufficient knowledge base to understand and use Java EE as it's intended, on enterprise-level applications.
If you want more information read the documentation, as I don't care to digest it for you.

What are the differences between api and sdk

Hi,
Could anybody clarify for me what are the difference between API and SDK? I googled for the answer, and couldn't find any thing on this topic.
Many thanks in advance.
javasfan

Is it correct to say that "a SDK includes all the
APIs"? or "API sits on top of the SDK"?It's a bit weird to say either. First, the JDK doesn't include all APIs. Just the J2SE core API. Others, like 3rd party libraries or J2EE are not included. Second, if you mean the API docs, they're also not included IIRC.
It'd technically only be correct to say "the SDK provides an API", I guess. The example is very lame, but: if the SDK is a machine, the API is the sum of its buttons and levers and gauges and intakes and outlets and exhausts. The API docs are the manual.

Difference between JDK , JRE J2EE

Hi
Would anybody just show the difference between JDK , JRE , J2EE , and J2RE
Thanks alot

JDK - Java SDK from Sun
JRE - Java Runtime Environment
J2EE - Java 2 Enterprise Edition
Basically, JDK is J2SE, Java Standard Edition. You need this to develop and to compile standard Java software. JRE allows only execution without any special components. J2EE is extension to J2SE. It contains Business or Enterprise components like Java Beans.

Difference Between JMS and RMI

Difference Between JMS and RMI in J2EE Technologies

STFW
JMS - http://www.google.co.za/search?hl=en&q=what+is+jms&meta=
RMI - http://www.google.co.za/search?hl=en&q=what+is+rmi&meta=

What is the Difference Between Adapter and Proxy

Hi Master,
I want to know the Difference Between Adapters and Proxies.
And when we are using proxies and Adapters....
Regards,
SReddy

Adapters are part of the Adapter Framework. Adapters provide the technical connectivity to enable the integration of SAP and non-SAP applications through XIs Integration Engine.Again, Adapters are used for connectivity from and to external systems with XI that cannot communicate via proxies.Adapters are only required in SAP systems older than 6.20 and external systems.
Systems based on 6.20or higher can communicate directly with proxies.
The literal definition of a proxy is an object / process authorized to act for another; an agent or a substitute. In simpler terms, proxies in the XI context are objects used to encapsulate the creation (from a sender system) or parsing of XML (at a receiver system) as well as the communication with the relevant runtime components required to send or receive those messages.
Proxies are generated from Message Interface in IR.
The Proxy Runtime controls these objects / processes, and can itself be controlled by the applications it communicates with. The Proxy Runtime currently has the following components available: 1. ABAP Proxy Runtime Communication using XI or Web Services a. Web Service Runtime 2. Java Proxy Runtime Communication using XI (J2EE) The objects that the Proxy Runtime then controls are created via Proxy Generation, for both ABAP and Java. In the following sections a client proxy is used by an application to send messages outside of the system it resides in (normally to the IS in this context). Conversely, a server proxy is used by an application to receive messages from sources outside itself (again, normally the IS in this context).

What's the difference between jsp and jsf?

who can tell me what's the difference between jsp and jsf?
I'm puzzled when I found some of the technology in jsp is so similar to the ones in jsp( javaserver page)

Hi,
Find the difference between JSP and JSF
1. A developer has more control with JSP, but (should) get easier development with JSF
2. Event handling is done differently in JSP (HTTP) and JSF (Java)
3. The UI is designed differently (or should be at least) with JSP (markup) and JSF (components).
4. The end product should also be defined differently - JSP page versus a JSF application.
Is this the only thing that is need to make a decision for either or? Probably not. There are other pieces that need to be taken in account when deciding which technology to use - tools support, enough components, type of application etc.... At this point there are not enough JSF components (although there are some interesting projects underway - Ajaxfaces, Myfaces, ADF Faces, and WebChart 3d) and enterprise tools support is still limited to a few tools vendor. Looking at our ADF Faces components they are currently available as early access (not production) and demands for these components are stacking up, literally, outside my office doorstep. Although I would love to make them production - now! - it is not a viable solution since we are still checking features and fixing critical bugs.
All this combined - not enough enterprise level components in production, lacking tools support etc... - leave customers in a vacuum where the decision is either to continue with JSP, since it is mature and has a wide developer base, or move forward with JSF not sure if the support, or the developers will be there. This is particularly sensitive to customers that need to get started now and be production by summer.
If you are in this vacuum here are some key points promoting JSF:
1. Fundamental unit is the Component
2. Built in event and state management
3. Component sets can be provided by any vendor
4. Closer to ASP.Net or Swing development
5. Choice of UI technology
6. Scale up (rich clients)
7. Scale down (mobile devices)
8. Built into J2EE containers in J2EE 5.0 (tentative)

What's the difference between JRE and HotSpot

What's the difference between JRE and HotSpot?
Where can i find HotSpot for Solaris?
tks!

The difference between the two is explained at:
http://www.sun.ca/software/communitysource/hotspot/
and
http://www.sun.ca/software/communitysource/hotspot/faq.html
It's included in the J2SE v1.3.1 release.

What are the differences between StreamConnection and SocketConnection?

hi guys.
i desperately needs some explanation. i have google and the results are nt useful
What are the differences between StreamConnection and SocketConnection?
i have a j2se server using a serverconnection.
the articles on the web are contradictory as a result i am really confuse and dont know which one i should use in creating the socket connection in my j2me midlet
PLS Pls help me .

hi, a socketConnection is a subclass of StreamConnection. In other word, a StreamConnection is an interface (template) to improve more specific connection like : FileConnection, HttpConnection, ...
If you have to connect a specific server, use SocketConnection, if it's a HTTP server use HttpConnection ...

What's differences between jaas and jacc?

lately i saw a new java scurity released on http://java.sun.com/j2ee/javaacc/; it seems like similar to JAAS (http://java.sun.com/products/jaas/); though, reportedly, jacc concerned more detail in authrization, however, there's autherization api been included as i know. is there anyone be able to tell me what's differences between jaas and jacc? or where there's resource or article exaplained detail about this issue?
i appreciate any suggestions.
thank you very much,

From what I saw, the JACC specifically deals with what is currently called Container Managed Security. JAAS is something that would be used on top of JACC.
See also:
http://java.sun.com/j2ee/1.4/docs/tutorial/doc/Security11.html
JACC contracts provide the following benefits:
- JACC moves security administration and decision-making responsibility from the container to the security providers.
- JACC enables the use of a common policy across different security systems.
- J2EE system integrators can integrate containers with existing authorization policy infrastructure
re Jaap

Difference Between SCA and SDA

Hi,
I am preaparing for the SAP Certification exam , my exam is on 20 of this month . Can anyone explain me the difference between SCA and SDA .How are they different from each other and the benefits of using them.
appreciate quick responses.

Hello,
Here u go ...
The Software Deployment Archive (SDA) is the delivery format for SAP applications in programming languages other than ABAP, for example applications of the J2EE Engine. It is an archive format that is compatible with ZIP and that can be used as a container for other archives. The SDA contains the manifest information, that is package-related data of the contained archive (e.g. jar, war) and an SAP manifest containing additional information about the software logistics. Larger entities can be created in SCA format in the second step from the different SDAs. A Software Component Archive (SCA) is the physical representation of a version of a software component. It contains a selection of SDAs that describe a precise version. Updating an SCA always results in a new version of the software component.
I hope this solves your question
Thanks
Pankaj

What's the difference between trace and log in XI?

Hi all,
On both J2EE and ABAP, there are both tracing and logging functionalities. Can anyone explain me the difference between trace and logging?
Regards,
Hui

From SAP Notes
Log file:
A log file contains generally intelligible information for system administrators. The information is sorted by categories and is used for system monitoring. Problem sources or critical information about the status of the system are logged in this file. If error messages occur, you can determine the software component that has caused the error using the location. If the log message does not provide enough details to eliminate the problem, you can find more detailed information about the error in the trace file.
The log file is located in the file system under
"/usr/sap/[SID]/[instance]/j2ee/cluster/server[N]/log/applications.[n].log" for every N server node.
Access the file with the log viewer service of the J2EE visual administrator or with the standalone log viewer.
Trace file:
A trace file contains detailed information for developers. This information can be very cryptic and extensive. It is sorted by location, which means by software packages in the Java environment, for example, "com.sap.aii.af". The trace file is used to analyze runtime errors. By setting a specific trace level for specific locations, you can analyze the behavior of individual code segments on class and method level. The file should be analyzed by SAP developers or experienced administrators.
The trace file is located in the file system under
"/usr/sap/[SID]/[instance]/j2ee/cluster/server[N]/log/defaultTrace.[x].trc" for each N server node.
Access the file with the log viewer service of the J2EE visual administrator or with the standalone log viewer.
Regards,
Prateek

Difference between FileInputStream and DataInputStream

Hai everyone,
I want to know the difference between FileInputStream and DataInutStream.As i am new to this environment i am little bit confused between the two. So i request you to explain the difference with an example so that everything will be clear for me.

FileInputStream is for reading bytes from a file, as is indicated in the API docs: http://java.sun.com/j2se/1.5.0/docs/api/java/io/FileInputStream.html
DataInputStream is for reading java primitives (byte, char, short, int, long, float, double, boolean) through some other stream, as is indicated in the API docs: http://java.sun.com/j2se/1.5.0/docs/api/java/io/DataInputStream.html
If you want to read Java primtives from a file, you'd use them together: FileInputStream fis = new FileInputStream("somefile"); // for reading bytes from the file
DataInputSeam dis = new DataInputStream(fis); // for interpreting bytes read by fis as Java primitives
int ii = dis.readInt(); // dis uses fis to read 4 bytes from the file, and interprets them as a Java int You should probably go through this: http://java.sun.com/docs/books/tutorial/essential/io/index.html

Difference between J2SE and J2EE...

Similar Messages

Maybe you are looking for