Java

13-Jan-11 11:11

Hi,
m a beginner for java, n i wanna know which simulator/editor is good for doin java programming plz.

RaviRanjanKr13-Jan-11 21:16

RaviRanjanKr

13-Jan-11 21:16

I do my Java programming with netbeans and Eclipse and till now these two editors are best editors for me.
[Specially Eclipse]

Richard MacCutchan13-Jan-11 22:15

13-Jan-11 22:15

Eclipse[^] is a very easy to use IDE for creating and testing Java programs, assuming you are reasonably familiar with the language. If you want a "drag & drop" program builder, then NetBeans[^] may be a better choice. In either case you should spend some time going through the Java Tutorials[^].

I must get a clever new signature for 2011.

TorstenH.14-Jan-11 0:03

14-Jan-11 0:03

Eclipse. There is a wide spread support on this one.

Try to write as much as you can yourself - click&drop are not really helpful as you do not see the code behind the action.

I also recommend buying an old fashion book, it's much easier to read something in a book while programming than to switch the screen multiple times.

regards,
Torsten

I never finish anyth...

Richard MacCutchan14-Jan-11 0:28

14-Jan-11 0:28

TorstenH. wrote:
than to switch the screen multiple times.

Or get a second monitor. Wink | ;)

I must get a clever new signature for 2011.

aesthetic.crazy14-Jan-11 12:59

14-Jan-11 12:59

i want to study a code, a difficult n lengthy code, n was wondering if there is any option in any of these through which i can run the code step by step (simulator will run each step of the code n stop n then run the next one, like breakpoints) to get a better understanding of my program/code flow? which one is suitable n what is the name of such option?

aesthetic.crazy14-Jan-11 13:00

14-Jan-11 13:00

is there any software through which i can understand the flow of any code? or can have any diagrammatic view?

Richard MacCutchan15-Jan-11 0:07

15-Jan-11 0:07

aesthetic.crazy wrote:
n lengthy code, n was

I'm not sure what these 'n' characters mean, but please spell words in full so people can properly understand your questions. Remember that English is not everyone's first language.

As to your question you just need to use the built in debugger with Eclipse or NetBeans and single step through the code to see what is going on.

I must get a clever new signature for 2011.

aesthetic.crazy15-Jan-11 12:09

15-Jan-11 12:09

I have this version of eclipse but i didnt find Debug single step option anywhere, kindly guide me.

Eclipse IDE for Java Developers

Version: Helios Service Release 1
Build id: 20100917-0705

Richard MacCutchan15-Jan-11 21:38

15-Jan-11 21:38

Go to your source file and double click a line of code to set a breakpoint, then using the menu find the Debug -> Run command and it will launch Java in debug mode. Or you could use the built in help.

I must get a clever new signature for 2011.

startNetworkServer

pancakeleh11-Jan-11 21:11

pancakeleh

11-Jan-11 21:11

i am using netbeans and i want to host a local dtaabase so i used the java db. However when i launch the startNetworkServer, i get the follow error.

http://img830.imageshack.us/img830/9448/whym.png[^]

anyone? who knows the solution?

Richard MacCutchan11-Jan-11 21:20

11-Jan-11 21:20

The message seems fairly clear to me: either the file does not exist or you do not have access rights to that directory.

I must get a clever new signature for 2011.

TorstenH.11-Jan-11 21:39

Re: startNetworkServer [modified]

11-Jan-11 21:39

Yes, Richard says it: It's a FileNotFoundException.

Looks like a Win7 machine. Files in the "Programm Files"-folder are not allowed to be changed by other files. Set permission on the derby-stuff.

regards
Torsten

I never finish anyth...

pancakeleh11-Jan-11 21:49

pancakeleh

11-Jan-11 21:49

yup i am using a win 7. How shld i go abt solving it?
Frown | :(

http://img600.imageshack.us/img600/8999/capture1ml.png[^]

Right now when i run the startNetworkServer, there isnt any access deny but when i try to connect to the database, it will have the error shown above.

I have a local database deployed on my local pc. is there any way i can connect my laptop to the local database from my local pc so that i need not create one for my laptop but still able to use the database?

modified on Wednesday, January 12, 2011 4:01 AM

TorstenH.12-Jan-11 0:17

12-Jan-11 0:17

The server is not accepting your connection... why? is it the right address?
Confused | :confused:

regards
Torsten

I never finish anyth...

basic question about Namespaces in Java

pancakeleh12-Jan-11 19:36

pancakeleh

12-Jan-11 19:36

i manage to connect to my desktop's local connection already Smile | :)

nic77m10-Jan-11 9:05

nic77m

10-Jan-11 9:05

I'm a newbie....if given this snippet of code

Sam.Leg.Hair.Cell

how am I suppose to know which one below is it just by looking at it
1. Sam.Leg.Hair is the namespace and Cell is the name of an object
2. Sam.Leg is the namespace and Hair is an object which contains the object Cell
3. Sam is the namespace and Leg contains the object Hair which contains the object Cell
4. Sam is an object that contains an object Leg which contains and object Hair which contains an object Cell

Luc Pattyn10-Jan-11 10:54

Luc Pattyn

10-Jan-11 10:54

It ain't 2,3,4; if you must pick one it would be 1, although strictly speaking it would then be a namespace followed by a class name (or type name), not an object. And it really depends on context, your "snippet" isn't a real snippet, where is that string located? in a namespace statement? in a class reference?

I suggest you read an introductory book on Java if you're interested or need to know this (and much more). I also think namespaces and class names by convention use lower-case in Java.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

TorstenH.10-Jan-11 23:50

10-Jan-11 23:50

I also think namespaces and class names by convention use lower-case in Java.

NO! Namespaces are lower-case, Objects are definitely starting upper-case!

@ nic
The namespace or package declaration divides your application into different parts.

Normally you will have some kind of user interface(UI or GUI if it is a graphical one), some services and some kind of database.
These three parts have their own namespaces:

package app.gui; // the GUI in general
package app.gui.page; // the pages of the GUI
package app.gui.page.view; // parts of the pages

package app.database; // the database
package app.database.type.person; // the person aka the object 'Person' is in here
package app.database.type.person.extremity; // obejcts 'Leg' and 'Arm' are declared here - a person can have more than one of each.

package app.services;
package app.services.actions; // things the person can do like "Running", "Working", "Sleeping"
package app.services.status; // providing status messages about the person "EnergieStatus", "HealthStatus"

The GUI gets it's data, that is to be shown/modified, from the services. Changes are submitted to the services.
The database is served/controlled by the services. The database package also has different packages underneath to organize the objects.

In this case the classes/ objects in the database package do not know anything about the GUI - and the GUI doesn't need to know anything about the database. The services is some kind of agent / mediator, which is positioned in the middle to serve (what is probably the cause it is called "service" ...).

So declaring packages will give you more control on your code and will organize your app.

You can read more about this basic organizing stuff - try to search for MVC (Model-View-Controller).

regards
Torsten

I never finish anyth...

David Skelly11-Jan-11 2:03

David Skelly

11-Jan-11 2:03

Actually it could be any of the above, 1, 2, 3 or 4, allowing for the messed up naming convention.

Example: java.util.Map.Entry is a class called Entry inside a class called Map inside a package called java.util.

Inner classes can contain nested inner classes, that is legal in Java, although not good design. So you could have mypackage.A.B.C or even A.B.C.D if A is located in the default package. Most Java programmers seeing Able.Baker.Charlie.Delta would see it as four class names because of the naming convention that classes start with uppercase characters and packages start with lower case.

Also, Java packages are not hierarchical, so the java package does not really contain the util package. They are two separate packages, one called java, one called java.util. If you are using reflection, you can get a Package object that represents a package, but there is no way to get sub-packages since there is no such concept in the Java language itself. (OK, you can list all the packages and parse through them by name yourself which is how Eclipse and NetBeans do it.) Java files (source and class files) are stored in a hierarchical file structure, but the actual packages themselves are not seen as hierarchies by the JVM at runtime. The pseudo-hierarchy of packages is there for human convenience, not for the compiler or JVM.

Re: installshield [ 5xRepost ]

Luc Pattyn11-Jan-11 2:07

Luc Pattyn

11-Jan-11 2:07

I stand corrected. Forgot about inner classes. Thanks. Blush | :O

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

installshield

lucky_12215-Jan-11 22:32

lucky_1221

5-Jan-11 22:32

Hi,
In installshield, i am calling the third party application "how to findout the application installed or not?". In some cases i have to handle that operations like cancel the setting and finish application. How to findout?

Any body known.....?please give me the reply.......
thank u.

Richard MacCutchan6-Jan-11 2:39