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Index ‹ java-programmer
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- 1
- [Off-topic] cvsHello,
sorry for the off-topic question but I think this is a good
place to ask. I plan to develop open-sourced web application
which integrates CVS browser, a bug tracking system and some
more interesting features to support development both
open-sourced and commercial projects. I would like to know
whether it is worth to invest my free time for such a tool.
CVS is rather an old system and I have no idea how widely is
used in development teams. So my question is easy: Do you use
CVS in your development?
Thank you,
jozef
- 1
- Making the most of codeI have a web site that uses JSP and some back end classes to manage
data in a MySQL database. It does okay and has run well for about 3
years. It has, however, grown to the point where I need to redesign
some of it to be more dynamic. I've recently started incorporating
Hibernate and JavaServer Faces to ease the development now and make it
easier for me to make changes later on. Or at least that was my plan.
Each database table maps to a Java class. I will easily have 25-30
tables before I am done. I am okay with 25-30 classes to represent
the data, but my concern is when it comes to the associated classes
needed to manage the data connections and such. I find that I am
cutting and pasting way too much similar code into these separate
classes.
For example.
I have a HibernateDAO class that manages the Hibernate session.
Each class then has its own DAO class that extends the HibernateDAO
class and the code within the extended DAO classes is virtually
identical.
Here is one method from my clientDAO class.
public Client add( Client client) {
try {
begin();
getSession().save(client);
commit();
return get(client.getClientId()); //not every class
will have a clientId member
} catch (HibernateException e) {
rollback();
System.out.println( "Could not add client: " +
client.getClientId() + " : " + e); //message hard coded for client
class
return new Client();
}
}
And then in my ContactDAO class I have this.
public Contact add(Contact contact) {
try {
begin();
getSession().save(contact);
commit();
return get(contact.getId()); //not every class will have
an Id member
} catch (HibernateException e) {
rollback();
System.out.println( "Could not add contact: " +
contact.getId() + " : " + e); //Message hard-coded for contact class
return new Contact();
}
}
Note that the code is virtually identical.
The begin(), getSession(), rollback(), and commit() methods are all
from the HibernateDAO superclass.
I tried using Generics to make the return type and parameter <T>, but
this only gets me so far. I cannot declare a new instance of <T>, or
at least I don't know how to. And the method uses values that are
specific to the class in question. I.E. not every data class will
have a getId() method.
I am not sure if any of that made sense, but the crux of the issue is
I am trying to avoid cutting and pasting code and then having to
remember to update it in 25 different places when I make a change. I
feel like there is a way to do what I want, but I just don't have the
experience to see it.
If anyone can point me toward some documentation that might help set
me straight, I would appreciate it.
Thanks.
- 4
- which data structure best fits this?hi,
i am looking for a data structure for fast retrievals... and here is my
scenario.
this table is about foreigncy exchange. i will have a buy currency,
sellcurrency, levels, and rate.
A transaction involves from a BUY currency to Sell currency, and it can
have multiple levels, meaning... if the sell amount is 1000, the rate
is 1.1, but if the sell amount is 2000, the rate is 1.2..etc...
Say there is a fixed amount of currencies that I need to maintain (say
10 type only) And I need to store all these rates in a structure, for
fast retrieval..
More concrete example.
Sell : USD Buy: EUR Level: 1 - 1000 rate: 1.1
Sell : USD Buy: EUR Level: 1000 - 5000 rate: 1.2
Sell : USD Buy: EUR Level: 5000 - 99999999 rate: 1.3
Sell : USD Buy: CAD Level: 1 - 1000 rate: 1.1
Sell : USD Buy: CAD Level: 1000 - 5000 rate: 1.2
Sell : USD Buy: CAD Level: 5000 - 99999999 rate: 1.3
Sell : USD Buy: GBP Level: 1 - 1000 rate: 1.1
Sell : USD Buy: GBP Level: 1000 - 5000 rate: 1.2
Sell : USD Buy: GBP Level: 5000 - 99999999 rate: 1.3
------ So, Sell for USD type is finished here.
Sell : EUR Buy: USD Level: 1 - 1000 rate: 1.1
Sell : EUR Buy: USD Level: 1000 - 5000 rate: 1.2
Sell : EUR Buy: USD Level: 5000 - 99999999 rate: 1.3
Sell : EUR Buy: CAD Level: 1 - 1000 rate: 1.1
Sell : EUR Buy: CAD Level: 1000 - 5000 rate: 1.2
Sell : EUR Buy: CAD Level: 5000 - 99999999 rate: 1.3
Sell : EUR Buy: GBP Level: 1 - 1000 rate: 1.1
Sell : EUR Buy: GBP Level: 1000 - 5000 rate: 1.2
Sell : EUR Buy: GBP Level: 5000 - 99999999 rate: 1.3
------ Sell for EUR is finished here.
so on with GBP, and CAD.
my requirements:
Say, someone tell me, what are all the rates for all the levels and
BuyType from EUR as sell?
Then that means I have to send back all the EUR as sell type.
Or, if someone say, what are all the rates for all the buytype for USD
from EUR as sell?
Then that means i have to send back all the EUR as sell, and USD for
Buy.
Or, if someone say, what are all the rates for all the buytype as GBP?
Then, i will have to send back all the buytype as GBP (including all
levels)
Or someone can just ask for a specific level as well for any buy type
of sell type, or both.
I was thinking about hash of hash... but if i have the Sell type as key
of the outer hash... then the inner hash will need to have a buytype as
the key... but then, i will have multiple levels...if i put the
multiple levels in an array of an object, and this object as the value
of this inner hash, that should be fine... but i am worry about the
speed.
Ideas?
thanks,
T
- 4
- overriding attributesI have a class A and a class B inheriting from A.
I have a class C and a class D inheriting from C.
I would like to have a attribute ATTR of type C in A. But in B, I would
ATTR to be of type D.
What should I do?
regards,
Andersen
- 4
- error starting java .jar app - classpath issue?I'm reluctant to post to a developers list, but this question
got no help at debian-user in the past 2 days. It seems to be
debian-related more than generic java-related.
This is likely a very simple issue. I've never tried to run a
java .jar library on debian before.
For all commands discussed below, no CLASSPATH environment
variable has been defined.
No errors if I switch to the .jar file directory and issue this
command:
$ java -jar tt.jar
But if if try either of the following commands from another
directory, the errors shown below commands appear:
$ java -jar /usr/share/java/tt.jar
$ java -classpath /usr/share/java/tt.jar -jar /usr/share/java/tt.jar
Exception in thread "main" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(ImageIcon.java:161)
at com.taubler.timebox.submit.SubmitExtensionWidget.<init>(SubmitExtensionWidget.java:16)
at com.taubler.timebox.submit.SubmitManager.<init>(SubmitManager.java:52)
at com.taubler.timebox.TimeTracker.<init>(TimeTracker.java:54)
at com.taubler.timebox.TimeTracker.main(TimeTracker.java:1115)
I wonder if it may just be a matter of learning how to correctly
set the CLASSPATH before issuing the java command on .jar
libraries held in /usr/share/java/. I could not find any
clear guidance about the usual CLASSPATH practice on debian.
(I run sarge. Java is from blackdown j2re1.4 and j2sdk1.4.
Installed without a hitch.)
(App in question is a timekeeper program. See
http://www.taubler.com/timebox/.)
Thanks.
--
Gordon Pedersen email***@***.com
St Paul, Minnesota, USA
--
To UNSUBSCRIBE, email to email***@***.com
with a subject of "unsubscribe". Trouble? Contact email***@***.com
- 4
- Reading a line from a fileHi to all, I'm trying to read from a file, line by line, and parse out
the data, by using the line.split(" ") function, and I have a file that
has 8 entries total per line, which means that it supposed to read up
to , array[7], but for some reason, when I run it , it says array
outofboundaries. The only thing here that is to notice, is that the
value at 7 might be either a string or an empty string, can that be a
problem?
Thanks
- 4
- Best site for javahttp://javamobileweb.cogia.net
interactive site for java , mobile , wap and web .
a very helpful team also for all your question and problem
- 6
- Problem with Tomcat server on windows Vista when used with javaHi,
I have one c++ application to get number of monitors from
system. I am calling .exe of c++ application using java api through
tomcat server in browser on window vista. right now I have two
monitors attached in the system.one primary and other secondary. but
when i call c++ application using java api through tomcat server, it
lists only one primary monitor.
i have some scenario for behavoiur of such application:
(1) when i run directly c++ application on vista it works fine.(gives
two monitors)
(2) when i run using sample java code without tomcat server it works
fine..(gives two monitors)
(3) when i am calling from browser through tomcat server it displays
only one monitor.
(4) one important thing is that when i call same thing on Windows XP
it works fine..(gives two monitors)
can anybody tell that what could be the problem to get list of monitor
through tomcat server on windows vista?
Ravi.
- 8
- netbeans install.log error#################install.log############################
(Jul 14, 2004 2:07:28 AM), Setup.product.install, com.installshield.product.service.product.PureJavaProductServiceImpl$Installer, err, ProductException: (error code = 601; message="JVM not found")
STACK_TRACE: 8
ProductException: (error code = 601; message="JVM not found")
at com.installshield.product.actions.JVMResolution.install(JVMResolution.java:171)
at com.installshield.product.service.product.PureJavaProductServiceImpl$InstallProduct.checkUninstallerJVMResolution(PureJavaProductServiceImpl.java:4747)
at com.installshield.product.service.product.PureJavaProductServiceImpl$InstallProduct.install(PureJavaProductServiceImpl.java:4523)
at com.installshield.product.service.product.PureJavaProductServiceImpl$Installer.execute(PureJavaProductServiceImpl.java:3727)
at com.installshield.wizard.service.AsynchronousOperation.run(AsynchronousOperation.java:40)
at java.lang.Thread.run(Thread.java:595)
###################end install.log###################
After downloading the .jar I used javac -jar on the file, and it launched
the installer window. I clicked all the appropiate buttons and the
graphical installer even said netbeans was now installed. The install.log
file disproves that, unfortunately.
what went wrong pls?
thanks,
Thufir Hawat
PS: I posted this again to add "netbeans" to the subject line.
- 8
- Application StoppingI have an application I am working on that keeps shutting down. There
seems to be no rhyme or reason for the shutdown. It happens randomly.
Sometimes it will work other times it won't. I'm starting to think it
might be a windows problem, possibly a process that is running. As my
App is running, Windows thinks the program is not responding. No big
deal, but I'm starting to think that this might be the problem. Here
is the error code it is getting in the Event log.
Faulting application gl.exe, version 1.0.0.0, faulting module
msjava.dll, version 5.0.3810.0, fault address 0x000c4a7e.
It doesn't seem to have anything to do with memory, or the volume of
data I'm processing.
I don't know if anyone will have any advice, I'm grasping at straws.
I'm running Windows XP pro if that helps.
Thanks to anyone with any advice.
- 12
- Leaf linked binary treeHi,
I need a LeafLinked Binary Tree for one of my current projejcts but I
can't find any. Does somebody know a good and performant implementation
I could use or do I have to code it myself?
Thanks,
Snyke
- 12
- 12
- IDE and good bookHi,
What is the best IDE for Java development:
1)eclipse 3.1
2)sun 1
3)jbuilder
4)gui's are for wusses use vi and a command line ant
What is a good book to learn java 1.4?
What is a good book to learn swing?
thanks in advance
- 12
- 15
- HP Desktop for sale!Hi,
I have an unused HP Pavilion with the fallowing specs:
# Processor: AMD Athlon 64 X2 4000+ (2.1GHz, 2000MT/s System Bus)
# Memory: 2048MB PC2-5300 DDR2 SDRAM memory (2x1GB) (expandable to 8 GB (4 x 2 GB) (64-bit OS)/ 4 GB (4 x 1 GB) (32-bit OS))
# Hard Drive:320GB 7200RPM SATA 3G (3.0 Gb/sec) hard drive
# Optical Drive: 16X DVD(+/-)R/RW 12X RAM (+/-)R DL LightScribe SATA drive
# Expandable Drive Bay: HP Pocket Media Drive bay
# Video Graphics: Integrated graphics
# Network Interface: Integrated 10/100BaseT network interface
# Sound: High Definition 8-channel audio
# Fax/Modem: 56K bps data/fax modem
# Operating System: Genuine Windows Vista?Home Premium
This is "used" but basically brand new (it has literally been on for no more than 6 total hours..) is only 1 month old..
PRICE: $425 OBO
Email- email***@***.com
|
| Author |
Message |
nikolaj
|
 Posted: 2003-7-4 20:43:00 |
Top |
java-programmer, read from file in jsp
I'm develloping a site based on jsp.
In my javacode I want to read from a file located in the document root
of the web application. How do I do this when I dont know the name of
the host.
Should I consider locating the file somewhere else. It should actually
only be accessible from the code of the application.
Thanks for your help.
Nikolaj
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Chris Smith
|
| Posted: 2003-7-4 22:28:00 |
Top |
java-programmer >> read from file in jsp
William Brogden wrote:
>
> "Nikolaj" <email***@***.com> wrote in message
> news:email***@***.com...
> > I'm develloping a site based on jsp.
> > In my javacode I want to read from a file located in the document root
> > of the web application. How do I do this when I dont know the name of
> > the host.
> >
> > Should I consider locating the file somewhere else. It should actually
> > only be accessible from the code of the application.
>
> The servlet API provides for this in the ServletContext class. Example:
>
> InputStream in = config.getServletContext().getResourceAsStream(
> "WEB-INF/surveys/survey.properties");
Well, the easier way to access the ServletContext is:
InputStream in = application.getResourceAsStream(...);
--
www.designacourse.com
The Easiest Way to Train Anyone... Anywhere.
Chris Smith - Lead Software Developer/Technical Trainer
MindIQ Corporation
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William Brogden
|
| Posted: 2003-7-4 23:21:00 |
Top |
java-programmer >> read from file in jsp
"Nikolaj" <email***@***.com> wrote in message
news:email***@***.com...
> I'm develloping a site based on jsp.
> In my javacode I want to read from a file located in the document root
> of the web application. How do I do this when I dont know the name of
> the host.
>
> Should I consider locating the file somewhere else. It should actually
> only be accessible from the code of the application.
The servlet API provides for this in the ServletContext class. Example:
InputStream in = config.getServletContext().getResourceAsStream(
"WEB-INF/surveys/survey.properties");
WBB
----== Posted via Newsfeed.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeed.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
---= 19 East/West-Coast Specialized Servers - Total Privacy via Encryption =---
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Index ‹ java-programmer |
- Next
- 1
- Is heavy client dead? Is swing applet dead?Today most Java UI developers are focusing on solutions like Struts,
Taperstry, and JSF. It seems that noone care about Swing applet as a
choice as rich client.
Is heavy client dead? I think heavy client solution like swing applet
is still good for business application. Especially for many internal
business projects. In internal business environment, the download speed
is usually not a problem. Swing also provides better GUI than html.
Swing has the ability to cache information on the client side which
save a lot of network calls to server.
Do you agree? Should we all forget about Swing and heavy client
solution, and vote for Struts and JSF?
Thank you
Jim
- 2
- 3
- truncating java doublesHi,
How do you truncate java doubles? I am trying to convert a double to a
number thats rounded to 3 decimal places - i can do this using BigDecimals
easily but cant seem to find anything to do the same with a double.
Thanks
- 4
- Debugging API classes in NetbeansWhen Im debugging my program in Netbeans, and I try to debug into API
(e.g. Swing JPanel) the debugger tells me that the source of the class
has not been found in mounted filesystem. Even though
c:\j2sdk1.4.2_02\src.jar is indeed mounted.
How do I debug into API classes?
Thanxxxx,
Barsum
- 5
- It don't work with "PBEWithHmacSHA1AndDESede". What wrong?Hi.
In the following source, I got the exception :
"java.security.NoSuchAlgorithmException:
Cannot find any provider supporting PBEWithHmacSHA1AndDESede"
<source>
Cipher cipher;
SecretKey secretKey;
PBEParameterSpec parameterSpec;
try {
PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray());
cipher = Cipher.getInstance("PBEWithHmacSHA1AndDESede");
SecretKeyFactory secKeyFac = SecretKeyFactory
.getInstance("PBEWithMD5AndDES");
secretKey = secKeyFac.generateSecret(keySpec);
parameterSpec = new PBEParameterSpec(salt, iteration);
} catch (NoSuchAlgorithmException e) {
} catch (NoSuchPaddingException e) {
} catch (InvalidKeySpecException e) {
}
</source>
The source above work with "PBEWithMD5AndDES". But, not
with "PBEWithHmacSHA1AndDESede". In the Sun's JCE API
Reference Guide, the "PBEWithHmacSHA1AndDESede" is the
standard name ( I use JDK 1.5 RC ).
What wrong? Thank you for your help.
- 6
- Thoughts on Code reviewI need some advice guys.. I am proposing that we get someone to do a
complete audit/review of our Java application codebase, about 1000
JSPs/Servlets and 100 EJBs. If I get firms to submit proposals, what
should I be asking /looking out for? I realise that running the
applications through a migration tool will help but I am looking for a
more through analysis of the actual codebase as well as assessment of
the architecture
Thanks
Arvie
- 7
- Check for time functionHello all...I have an issue with one of my java script functions that
I'm hoping someone can easily help with. I have a web based application
that we use to create/sign up for overtime. When we have holidays we
require our employees to sign up in 4 hr increments for the times we
post. I'm having trouble creating a time slot that ends @ 12am. 12pm
and all other hours work fine for start/end times. however 12am causes
problems. My actual script code for this function is below. Someone
help!!!
<SCRIPT language="JavaScript" src="frmvalidation.js"
type="text/JavaScript"></SCRIPT>
<script language="javascript">
function checkValidHoliday(value)
{
if (value=='Y'){
hourblock.style.visibility ='visible';
}
else{
hourblock.style.visibility ='hidden';
}
}
function checkHoliday(frm)
{
if(frm.txtIsHoliday.value=="Y")
{
strFromDt= new Date(frm.txtLimitDate.value);
strToDt= new Date(frm.txtLimitToDate.value);
FromHr=parseInt(frm.txtLimitFrom.value);
FromAMPM=frm.txtLimitFromAM_PM.value;
ToHr=parseInt(frm.txtLimitTo.value);
ToAMPM=frm.txtLimitToAM_PM.value;
if((FromAMPM=="PM") && (FromHr!=12))
FromHr=FromHr+12;
if((ToAMPM=="PM") && (ToHr!=12))
ToHr=ToHr+12;
var fromDt= new
Date(strFromDt.getFullYear(),strFromDt.getMonth(),strFromDt.getDate(),FromHr,0);
var toDt= new
Date(strToDt.getFullYear(),strToDt.getMonth(),strToDt.getDate(),ToHr,0);
//alert(toDt + " " + fromDt);
//alert(FromHr + " " +ToHr);
var HolidayBlock=(parseInt(frm.cboHolidayHours.value) * 360 * 10000)
;
//alert((toDt-fromDt) + " " + HolidayBlock );
if((toDt-fromDt)== HolidayBlock)//14400000)
return true;
else
{
alert("Please select "+ parseInt(frm.cboHolidayHours.value) +" Hour
Block only for Holiday!");
frm.txtLimitFrom.focus();
return false;
}
}
return true;
}
</script>
- 8
- Java SoundI am intersted in building an applet that can both play and record
sound files. I would like this to work on the widest range of platforms
(MAC, Linux, WinXP, WinNT, etc) and browsers. What would be the best
file format for the sound files to accomplish this? Would it be MP3,
WAV, or what? I am looking to have this work without any added packages
over and above JDK 1.4.x.
Thanks for any and all info.
- 9
- Array Error
I'm getting two errrors with the simple code below:
For line 5 I get " <identifier> expected "
For line 6 I get " ']' expected" and also " <identifier> expected "
What gives?
Thanks
------------------------------------------
1 package com.dlm.testing;
2 import java.util.Arrays;
3 public class Test1 {
4 public String[] names;
5 names = new String[50];
6 names[0]="Jones";
7 }
- 10
- Telephonic CredentialsI think it would be nice if I could prove to someone on the other end
of the phone I am me, and demand they prove they are who they claim to
be.
It could be done by letting a modem kick in for a second to exchange
challenge phrases to be encrypted by identification certificate that
might include name, address, phone number, expiry date, company.
Then if some charity I donate to phone me, I can be sure it is them.
There are so many scams out there.
It might also be done by each of us contacting an Internet server.
Has anyone heard of such projects?
--
Roedy Green Canadian Mind Products
The Java Glossary
http://mindprod.com
- 11
- Java installationTry to install Java on my computer, but Microsoft tells me:
THE JAVA RUNTIME ENVIRONEMENT CANNOT BE LOADED FROM <bin\hotspot\jvm.dll
What am I doing wrong to install that applet
please reactions
Robert
- 12
- Client application using Weblogic JMS ServerHello, I'm Jose from Barcelona,
I'm not at all expert on JMS, and my question is about how can I
connect a client application running java with a remote JMS Weblogic
Server. I've developed a client program and tested it with a Sun J2EE
server running on a XP box, but the goal is to make it run on an
iSeries machine connecting a WebLogic JMS Server.
My questions are:
Do I have to install some application software on the client box?
Is there any difference between connection with remote JMS servers and
connection with local ones?.
I hope you can help me.
Thank You.
- 13
- How to ignore invalid SSL CertificatesHi everybody :-)
I'm trying to build an application that serves as a Client Side
frontend for a webpage using HttpClient 2. Because I have some security
problems I decided that using https would be nice, but my SSL
certificates continue to fail validation and I'm wondering wether it is
possible to let HttpClient ignore Certification Failures? And if yes,
could you please give me a working example?
Greets,
- 14
- ""SEE THE BEST FRIENDS FOR YOUR SEX TALK""""SEE THE BEST FRIENDS FOR YOUR SEX TALK""
SEX TALK+SEX_JAFKJAJ;=SEXWORK
*********************************
http://www.freewebs.com/sociwok/
********************************
http://amigos.com/go/g903136-pmem
- 15
- Serializable : readObject and writeObjectHello,
I have 3 classes Personne, entreeb==>FileInputStream ,
sortieb==>FileOutputStream.
The code works one time. The problem is when I add serialized new objects
( launch again the code sortieb) I can't read all objects (entreeb) specific
a new objects added.
have you an idea?
Thanks form help
-----------------------------------------------------------
-----------------------------------------------------------
//Class Personne
import java.io.*;
class Personne implements Serializable {
private String nom;
private int age;
public Personne(String n, int a){
nom = n;
age = a;
}
public void aff() {
System.out.println (nom + " " + age);
}
}
------------------------------------------------
//Flux in
import java.io.*;
import java.util.*;
public class entreeb {
public static void main(String[] args){
Personne p;
int i=0;
try {
FileInputStream fist= new FileInputStream("Personne.ser");
ObjectInputStream oist = new ObjectInputStream(fist);
try {
while (true)
{ System.out.println("i="+i);
p = (Personne) oist.readObject();
p.aff();
i++;
}
} catch (EOFException e) { }
oist.close();
} catch (Exception e) {
System.out.println("Exception loading personne : " + e.getMessage());
}
}
}
------------------------------------------------------------------
//Flux out
import java.io.*;
import java.util.*;
public class sortieb {
public static void main(String[] args) throws IOException {
Personne p = new Personne("name", 55);
File f=new File("Personne.ser");
FileOutputStream fost= new FileOutputStream(f,true);
ObjectOutputStream oost = new ObjectOutputStream(fost);
int i=0;
while (i<5) {
System.out.println("i = "+i+ "p="+p);
oost.writeObject(p);
i+=1;
}
oost.close();
}
}
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