| Running Ant from BATCH FILES |
|
 |
Index ‹ java-programmer
|
- Previous
- 1
- convert hex to longHey
midp 2.0
J2ME Wireless Toolkit 2.2
JDK 5
Long id;
String arg1 = "0b"; //arg1 can also have values like "01", "0a" etc
id = Long.parseLong(arg1);
This converting isn't working with "0b" or "0a"... but I've read in the
documentation of jdk5 that this parseLong is overloaded:
public static long parseLong(String s, int radix), and I guess this is the
correct method to use, but I'm not sure what the second parameter (radix) of
this method is?
Jeff
- 1
- SAX reserved XML char encoding/decodingHi,
Is there an option to get the Sax parser (java 1.5) to convert xml safe encoding
sequences back to the original character, as returned by the Contents() event?
For example "<" back to "<" ?
Thanks.
Ben
PS (and what's with comp.lang.java.api? - nothing seems to register there since
sept 2004. , including my post of this question there)
- 2
- Random Access On a TableHi,
I've got a problem with 2 open Dataset:
That's I had opened a table running an SQL command like this "SELECT *
FROM XXX WHERE YYY=ZZZ" and i want to access to another table with the
keys came from previous ResultSet; BUT I dont want to run an SQL
command ; I'm looking for a command like
setnearest(keylist,keylist,...) then I want read the second table with
a while loop ( ex. (while !eof(second_table))).
Is there a way for me ;)
Thx in advance;
- 2
- Read-only methods for webservices with JavaBeansHello,
unfortunately i wrote this thread before in german, so i will do this
in english again.
Here we've got a standalone application which stores several data on
an SQL Server. In the last time we added a webservice to display and
sometimes modify several information from this data via webpages
(JSP). Many functions are already implemented and working fine. We
have webservicemethods returning objects stored in javabeans. To get
the data out of the beans, we have to use some get methods. Some data
is "READ-ONLY", so we don't want any set method there. The problem is:
If we don't write some "dummy" Set-Methods, wscompile will not
generate the needed get-Methods. We find that writing dummy-methods is
not a very fine way.
Is there another easy posibility to make the getMethods available for
the client without writing dummy set methods like this?
// That's what we don't need but have to write in order to make
wscompile ready to produce the getMethod
public void setName(String value) {}
// That's what we need only
public String getName()
{
return name;
}
Greetings and thnx a lot!
Andreas
- 2
- Java programs won't install on HP machineTrying to gather as many details as I can on a particular problem I'm
having right now. Just wanted to post what I have so far in case
anyone out there sees a light go off.
My company sells a java (version 1.4.2) based software package. We
use InstallAnywhere to install. Really haven't had a problem with our
installs on any flavor of Win machines to date.
A customer running Win98 SE on an HP machine (I'll get a model # asap)
calls today and says the installation program hangs his machine
completely after extraction part of the install.
We look at some install log data and it indicates that everything
extracted to Windows temp folder ok. From there the log says "starting
java..."
My understanding is what should happen at this point is the install
process is supposed to start a bundled JVM (i assume in the contents
extracted to the temp folder) and run a .jar file that completes the
installation process. It hangs the machine shortly into this java
part though (the last thing it tried to do is "UI mode set
to"......and off to oblivion...
We eliminated some known issues at this point. Minimum direct X
version to run InstallAnywhere installs is 8.1. Customer has 9.0
installed. All Win updates complete. No viruses on machine.
Anti-virus software disabled for the install. No video driver issues.
These are all things InstallAnywhere tells you to watch for.
Additionally, the install file is not corrupted (same file installs
fine on another machine).
We thought we'd install a current JVM on the machine for sh*t's and
giggles because I believe InstallAnywhere will use it if present.
Downloaded the latest from Sun and the install hangs the machine in
the same manner as our IA installer.
This machine appears not to be able to run java programs at all. What
gives?
- 6
- Tomcat 5.5 - IIS 6 using isapi_redirect.properties
I am trying to use IIS 6.0 as a front end for Tomcat which I have
working as expected. The issue I have is that I can only get it
working using the registry settings and not using
isapi_redirect.properties. We will have several sites and I want them
to independent of each other and I am not sure how to do this without
using the isapi_redirect.properties files. Please advise. Thanks in
advance.
- 7
- JAXB unmarshalling - missing referenced objectsHi
I've come upon a problem which I just can't figure out.
So, here's a little about the context. An enterprise-application is
running on a Java EE-server. Some POJOs are annotated as Java
Persistence entities aswell as JAXB-annotations to create wanted XML-
representation for them. All annotations are added manually (meaning
no auto-generated classes/factory). A Servlet acts as an interface
against an Ajax-enabled webpage. The script in the web-page retrieves
xml-representation from the servlet and should also send xml back on
the same form for persisting on the server. The script returns the xml
in string-representation.
And here's the problem. Marshalling to xml works just as it should.
The script returns an xml in the exact same form, but the
unmarshalling of it does not produce what is expected. An object for
the main class is created, however any referenced objects are not
created. Primitive fields are generated correctly. No error is thrown.
Simplified, this is how it looks:
---List.java---
@XmlRootElement(name="list")
@XmlType(name="ListType")
@Enitity //JPA
public class List implements Serializable {
private Long id;
private weekNumber;
private Set<Element> elements;
@XmlAttribute(name="weeknumber", required=true)
public void getWeekNumber() {
//...
}
@XmlAttribute(name="id", required=true)
public void getId() {
//...
}
@XmlElementWrapper(name="elements", nillable=false)
@XmlElementRef
@ManyToMany( //JPA
//...
)
public void getElements() {
//...
}
}
---Element.java---
@XmlRootElement(name="element")
@XmlType(name="ElementType")
public class Element implements Serializable {
//...
private Long id;
@XmlAttribute(name="id", required=true)
public void getId() {
//...
}
//...
}
---xml---
<?xml .....>
<ns2:list ..... weeknumber="3" id="21">
<elements>
<ns2:element ... id="42">
...
</ns2:element>
<ns2:element ... id="43">
...
</ns2:element>
...
</elements>
</ns2:list>
In this example, a List-object would be created by the unmarshaller,
however the referenced elements of class Element will not. And I have
no idea why! The package contains a jaxb.index with all class names,
and I also added an ObjectFactory, but the result was the same. Here's
the unmarshalling:
private <T> T recieve(Class<T> classType, String xml) {
JAXBElement<T> obj = null;
try {
JAXBContext jc =
JAXBContext.newInstance(classType.getPackage().getName());
Unmarshaller um = jc.createUnmarshaller();
obj = (JAXBElement<T>)um.unmarshal(new StreamSource(new
StringReader(xml)));
} catch(JAXBException jex) {
jex.printStackTrace();
}
return obj.getValue();
}
I hope someone has something wise to say about this. I've really
twisted my brain to try to figure it out!
Thanks.
- 7
- new to java, need helpSirs/Madam
I encounter the problem on date field.
Sometimes, when there is no date, then it will return the null object. When
I want to check by
aDate.toString() = "" or null, it throws exception.
How can I ensure they return the value or not.
Please help
- 8
- stdout being redirected to an open file?All,
Does anyone know why text sent to stdout might intermittently get sent
to an open file? I have some code which writes data to a file and logs
its activity using log4j. On Friday, the log statements began to
intermittently appear in the file. I know the following things are
true:
* The code did not change
* The configuration did not change
* The log4j Logger is mapped only to a ConsoleAppender, i.e. log
statements are written only to stdout
* The name of the file is always unique
Here is the code:
//Create a unique filename for the order
filename = "Order " + orderId;
//Create the file
logger.info("Creating file " + fileName);
File file = new File(fileName);
FileWriter fw = new FileWriter(file);
logger.info("Writing File Content ");
fw.write(fileContent + System.getProperty("line.separator"));
logger.info("Closing File ");
fw.close();
It smells to me of an O/S or app server problem in which the file
handle for the open file is being provided for calls to stdout. Has
anyone ever seen this?
Thanks,
Brian
- 11
- struts templates - template is inserted in wrong placeJust wondering if anyone else has run into this issue. I am using
templates in struts and I use the same template for every form. I
insert a page in one spot on my template file and it works fine on my
machine. When I upload it to the server, it suddenly starts inserting
the page about a quarter of the way down the template instead of where
it is defined to go. Has anyone else experienced this?
- 11
- Chennai - Java/J2EE Urgent RequirementGreetings,
One of the leading software development company is looking for
java/j2ee professional urgently. Interested candidates forward your
resume immediately to email***@***.com
You will be receiving call as soon as you send your resume.
All the best
TimesTickets.Com Team
- 12
- Differences between getImage and createImage and using ToolkitHello,
What are the differences between getImage and createImage,
and what if I want using toolKit - (getImage and createImage are static,
and I didn't find a way to create an Image object from a function of
toolkit).
I need a sample code, please.
Thanks :)
- 12
- Squeeze tabs closer together in JTabbedPane??Is there a way to squeeze the tabs closer together in a JTabbedPane? I
noticed there is some free space in the tab itself to the right of the
text in the tab. Don't want to overhaul the look of the GUI. Just want
to move the tabs closer together. An option I thought of, don't know
if it's the best, is to make the tab text image icons and show the
icons instead of text. Don't know if this will free up space.
- 12
- simple beginners questionHello,
I just got the SUN Java IDE. (Netbeans IDE 3.5.1)
Very very nice, and I worked myself through the tutorial (about making a
colorswitch).
Now, When I compile it gives no errors at all. So far so good.
But when I want to execute, it askes to "set project main class".
The only option it displays is the default project. But the "okay" button
won't highlight.
I cannot select anything else, nor can I roam directories to select
anything.
Can someone please help me out.
I feel kinda silly not even knowing how to start a kind of hello-world
applet. ;-)
best regards,
martin
- 14
- how does ANT work?On Fri, 11 Jul 2003, Roedy Green <email***@***.com> wrote:
> Does ANT work by parsing any changed file to discover the
> dependencies?
Depends on the task you are talking about. For most tasks, including
<javac> it does not. <javac> simply compares the timestamps of *.java
and *.class and compiles those files with outdated .class files.
<depend> in turn parses the compiled .class files to discover
dependencies, then compares the timestamps of .class files to the
.java files and deletes all .class files that are older then the .java
files of any class they depend upon. <javac>'s timestamp checking
after that is going to succeed then.
There are third party tasks like <javamake> - see Ant's external tools
page - that can do that in one step and are more sophisticated.
> Can it be relied on to recompile everything that needs it if a
> static final changes?
No.
And a static final primitive will be inlined by the compiler so even
<depend> will not detect the change (as it wouldn't detect the
dependency) - not sure whether <javamake> would.
> Is ANT smart enough to avoid loading the compiler over and over for
> each file; i.e. does it invoke it only once for the whole shot?
It will invoke the compiler exactly once per <javac> task (that
actually needs to compile at least one file).
Stefan
|
| Author |
Message |
mel_palmeruk
|
 Posted: 2005-6-9 18:02:00 |
Top |
java-programmer, Running Ant from BATCH FILES
Hi
Does anyone know is it possible to conditionally continue with a batch
file depending on the result of an ant script.
I want to only continue with the batch file if the ant command was
succesfull - otherwise abort the script for user to see the error.
Thanks in Advance.
|
| |
|
| |
|
Thomas Kellerer
|
| Posted: 2005-6-9 18:30:00 |
Top |
java-programmer >> Running Ant from BATCH FILES
On 09.06.2005 12:02 email***@***.com wrote:
> Hi
>
> Does anyone know is it possible to conditionally continue with a batch
> file depending on the result of an ant script.
>
> I want to only continue with the batch file if the ant command was
> succesfull - otherwise abort the script for user to see the error.
>
Just have a look at ant.bat how it's done there.
Thomas
|
| |
|
| |
|
| |
|
Index ‹ java-programmer |
- Next
- 1
- Tomcat 4.1.29 connectors on Linux problem ?
Hallo,
I have very strange problem with apache/mod-jk/tomcat installation
on Linux. I have installed very simple test servlet HelloWorld.class.
Well when I try to do some easy stability test and I call this
servlet from the same IE browser session more times I bring whole
tomcat to the state when it is not responding any more, even other
servlets from other sessions are not served. I have allready tried to
change acceptCount= and connectionTimeout= (even 0,-1) in server.xml
but without any satisfactionary results. Only the complete restart of
tomcat helps afterwards (!).
Thanks
Jan Kopinec
<Server port="8005" shutdown="SHUTDOWN" debug="0">
<Listener className="org.apache.catalina.mbeans.ServerLifecycleListener"
debug="0"/>
<Listener
className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"
debug="0"/>
<Service name="Tomcat-Apache">
<Connector className="org.apache.coyote.tomcat4.CoyoteConnector"
port="8009" minProcessors="5" maxProcessors="75"
enableLookups="true" redirectPort="8443"
acceptCount="300" debug="0" connectionTimeout="5000"
useURIValidationHack="false"
protocolHandlerClassName="org.apache.jk.server.JkCoyoteHandler"/>
<!--
<Connector className="org.apache.coyote.tomcat4.CoyoteConnector"
port="8080" minProcessors="5" maxProcessors="75"
enableLookups="true" redirectPort="8443"
acceptCount="300" debug="0" connectionTimeout="5000"
useURIValidationHack="false" disableUploadTimeout="true" />
-->
<Engine name="Standalone" debug="0" defaultHost="localhost">
<Logger className="org.apache.catalina.logger.FileLogger"
directory="/var/log/jakarta/" prefix="apache_log." suffix=".txt"
timestamp="true"/>
<Host name="localhost" debug="0" appBase="/home/tomcat"
unpackWARs="true" autoDeploy="true">
<Context path="/test" docBase="test" debug="0"
reloadable="false" crossContext="true">
<Logger className="org.apache.catalina.logger.FileLogger"
directory="/var/log/jakarta/" prefix="localhost_test_log."
suffix=".txt"
timestamp="true"/>
<ResourceLink name="linkToGlobalResource"
global="simpleValue"
type="java.lang.Integer"/>
</Context>
</Host>
</Engine>
</Service>
</Server>
- 2
- Apache Project Xalan XML/XSLT Processor Is Good, But Its Extension Not Work on Netscape/IEFirst, let me say I couldn't find a group discuss
XML/XSLT. So I only choose the closest groups to
post this message.
Here is part of my *.xsl file
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xalan="http://xml.apache.org/xalan"
xmlns:my-javascript-ext="my-ext1"
extension-element-prefixes="my-javascript-ext"
version="1.0">
<xalan:component prefix="my-javascript-ext" elements="whichever"
functions="hello">
<xalan:script lang="javascript">
function hello(w) {
return ("Hello " + w + "!");
}
</xalan:script>
</xalan:component>
....
<xsl:if test="function-available('my-javascript-ext:hello')">
<xsl:value-of select="my-javascript-ext:hello('World')" />
<br></br>
</xsl:if>
....
And this is part of my *.xml file:
<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<?xml-stylesheet type="text/xsl" href="http://myHostName/XML/myfile.xsl" ?>
....
This is working greate for an XML file iff (if only if) I type
java org.apache.xalan.xslt.Process -in myfile.xml -xsl myfile.xsl
or
java org.apache.xalan.xslt.Process -in myfile.xml
That is wonderful, when I set CLASSPATH with
/usr/local/xalan/bin/xalan.jar:/usr/local/xalan/bin/bsf.jar:/usr/local/xalan/bin/js.jar
So I can make my own extension to call my JavaScript functions and/or
Java Class methods inside a XSL file with XALAN Processor.
But unfortunaely this will NOT work on Netscape, Firefox, IE browsers,
even all these browser support XML/XSLT.
Anyone has some idea how should I make Apache Project XALAN's extension
work on a browser?
Thank Q!
- 3
- JavaMail sending problem and solutionI had chronic problems with sending email via smtp. I could sign in
via a mail client and send to a remote user just fine, but JavaMail
refused to send to any but local users, citing a 550 relaying problem.
All of the references I could find on the web told me to talk to my
mail admin, but I'm he and I also knew that if my mail client could do
it, so could I.
This solution requires that you log into the mail server as a normal
email user - you will have to create an (or use an existing) account.
You turn on smtp authorization by setting the a property you pass in
to get a session: the property is mail.smtp.auth and you set it to
"true". Then you create an Authenticator that returns a
PasswordAuthentication with your username and password in it.
Here's an excerpt of working code:
Authenticator authenticator = new Authenticator() {
public PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(FROM, PASSWORD);
}
};
Session mailSession = Session.getInstance(getMailProperties(),
authenticator);
Message email = new MimeMessage(mailSession);
try {
email.setFrom(new InternetAddress(FROM));
email.setSentDate(new Date());
email.setRecipients(Message.RecipientType.TO,
stringsToInternetAddresses(to));
email.setRecipients(Message.RecipientType.CC,
stringsToInternetAddresses(cc));
email.setRecipients(Message.RecipientType.BCC,
stringsToInternetAddresses(bcc));
email.setSubject(subject);
email.setText(body);
Transport.send(email);
retval = true;
} catch (Exception e) {
}
My getMailProperties includes the following:
mail.smtp.host=some.mail.host.com
mail.smtp.auth=true
I just post this here for posterity so maybe someone else doesn't go
through the hell I did to figure this out :)
- 4
- BufferedInputStream vs BufferedReaderHas anyone done any experiments on which is preferable -- putting your
buffering at the BufferedInputStream level or the BufferedReader level
when you have a Reader?
--
Roedy Green Canadian Mind Products
The Java Glossary
http://mindprod.com
- 5
- Check for site is up in programHi,
can any body guide me how to check whether the site i am using in my
Java application is up or not. Depending on that i would like to take
appropriate action.
thanks in advance,
atul
- 6
- comments when decompilingAnother newbie question:
When I decompile Java bytecode, will my comments come back through?
Makes sense that they woudln't, but I just wanted to check.
- 7
- Ajallerix : AJAX, simple, fast Web image gallery demo ; at Novellhttp://www.web20developers.com
http://www.web20developers.com/index.php?option=com_content&task=view...
Ajallerix : AJAX, simple, fast Web image gallery demo ; at Novell
AJAX - microlink pattern tutorial : A microlink is a link that opens up
content below it.
Ajax BBC News RSS Reader : demo by Nigel Crawley
AJAX Chat in Python with Dojo : at AquaAjax
Ajax Chess : multiplayer chess
Ajax examples at BackBase : examples demonstrating several aspects of
the Backbase technology.
Ajax examples at Rico : Inner HTML, JavaScript updater etc.
Ajax examples using ColdFusionMX, SQLServer, SOAP : Contact Manager,
NOAA 7 Day Forecast code and demos.
Ajax Feed TV : News feed
Ajax inline dictionary : Highlight any text on this site then right
click. A tooltip containing the definition of the selected word should
show up.
Ajaxload : Ajax loading gif generator.
Ajax Login Demo : Creating a secure login system using XMLHttpRequest
Ajax Newsletter Signup : A newsletter signup form that shows Thank You
on the same page.
ajaxProject : Project Management applicaiton with rich UI
Ajax Rater : A star rating system that uses Ajax.
AJAX-S : An Ajax-based slideshow system.
AJAX Spell Checker : spell check text / form content.
Ajax Toolbox : Tools for the Ajax Developer
Amazon Catalog Tree : Amazon Catalog Tree
Amazon Zuggest : Amazon product suggestion (like google suggest)
Askeet by symfony : Digg-like AJAX interactions; open source
Backbase - Ajax Demos : Ajax demos at BackBase
Basic Ajax Examples : Ping, track changes, drop down, Google suggest
hack etc at Clearnova
Behaviour : Fading lists, Sortable lists, Dropout boxen, Shaky lists
chat.app : ajax chat
Chihuahua Word Puzzle : daily word puzzles
Coloir : Ajax Slideshow
DHTML arcade/action games : a collection that demonstrate the power of
DHTML
DomAPI : Windows Desktop, Outlook-like, RSS Reader
Drag and Drop Shopping Cart Demo : at CyberDummy
Easy AJAX inline text edit 2.0 : edit a piece of text inline
Gmail Style Check Username AJAX Demo : at CyberDummy
Google Web Toolkit Example Projects : Hello World, Dynamic Table,
Desktop App Clone etc
GreyBox : Pop up window using idea of light box.
FiftyFourEleven: Ajax Examples
IntuiCat - ajax Catalogue : Ajax-based Catalogue Demo
jsLINB programming demos : LINB(Lazy INternet and Browser)
JSlog : Ajax logging tool.
JS/UIX Unix Shell : JS/UIX is an UN*X-like OS for standard
web-browsers, written entirely in JavaScript.
Lace : free web chat application
Lightbox : simple, unobtrusive script used to overlay images on the
current page.
Leightbox : Light Box with inline div's instead of AJAX calls.
Live Quote Demo : Simple way of creating an updating stock quote table
in ajax.
Magnetic Poetry : drag and drop poetry
Metatron Chat Engine : PHP/MySQL/JavaScript powered chat engine
Monket Calendar : online calendar
Multi List Drag Drop Demo : at CyberDummy
NetDirector : open and extensible framework for managing configurations
of common open source network services.
nexImage : Image processing demo
Opera Platform : Enabling AJAX applications on mobile phones
Orbeon examples : various examples illustrating the capabilities of
OPS, from the OPS Tutorial examples to XForms examples
OVO Suite : Online Virtual Office : virtual office limited demo
phpFreeChat : php Free Chat
S5: A Simple Standards-Based Slide Show System : S5 is a slide show
format based entirely on XHTML, CSS, and JavaScript.
script.aculo.us Reflector : image reflector script that uses uses
opacity-based fades
Slider Bar Demo : at CyberDummy
SmallestAjax : Smallest Ajax example in the world?
Spell Check demo : by Primal Grasp
Super Maryo World : Japanese game demo
Tacos : Tacos provides a library of useful Tapestry components. This
application provides some examples to get you started.
theList : to-do list / bug-tracker
ThickBox : ThickBox is a Lightbox than can show html pages as well as
images.
Tooltip.js : Tooltip.js is a simple class to make it possible to add
tooltips to your page.
Treehouse Chat : ajax chat
Tudu Lists : open-source to-do lists
WeBoggle : Ajax Boggle
XHTML live Chat : ajax chat
YahooSearchAsYouType : Yahoo search as you type
ZK Demo : demo programs for various components
- 8
- The beauty of TCP/IPI wrote:
> >I think Roedy's logic is that streams of large amounts of data are most
> >likely to be done via TCP rather than UDP, and therefore there exists
> >some correlation between TCP and more efficient applications
Roedy Green <email***@***.com> wrote:
> I was not trying to make any such statement.
I'm still not convinced. You say you're not making any such statement,
yet you go on to make such a statement.
> I was trying to point
> out that UDP and TCP/IP stream performance depend on different
> characteristics of the connection.
But they don't. Both UDP and TCP have latency and bandwidth. Latency
depends on the sum of the processing at each node and communication
times between hops, and bandwidth depends on the width of the narrowest
communication channel or the speed of the slowest processing node. Some
applications depend mainly on latency, and some on bandwidth; so the two
will perform differently, regardless of the choice of TCP or UDP.
The TCP/UDP choice is almost completely orthogonal to the question of
bandwidth or latency. The ONLY difference is that under TCP,
transmission errors can cause future data to be buffered at the target
node, and buffers have limited size... so in a path with very high
latency and occasional errors, TCP can fail to meet the bandwidth
potential of UDP over a similar path. Of course, the up-side is
reliable messaging, which is not available with UDP.
So...
> Either you have a continuous
> stream of data or you have intermittent packets.
Yes.
> Even if you were to
> use TCP/IP for exchanging intermittent packets, it will behave from a
> performance point of view like UDP.
There is no such thing as performing "like UDP". It can perform like a
continuous stream, or like intermittent packets with frequent round-
trips... but neither is more or less UDP.
As I said before, since many applications of UDP are for streaming large
amounts of data with no round trips (e.g., video streaming, multicast
broadcasting, ) and many applications of TCP are for intermitten
communication with frequent round-trips (e.g., telnet, ssh, ftp control,
most smtp and pop3 and imap, etc.), most people with experience in
network protocols will think that you've got it quite backwards. You
haven't really got it backward; there's really no significant
relationship at all.
> I thought I was stating something almost too obvious to mention, but
> apparently it is not.
I think your talk about TCP and UDP is confusing people. That's all.
Latency and bandwidth is not at issue.
--
www.designacourse.com
The Easiest Way To Train Anyone... Anywhere.
Chris Smith - Lead Software Developer/Technical Trainer
MindIQ Corporation
- 9
- Thinking in terms of Objects.Hello all,
I come from a background of Unix C-shell, WIN .bat programming and am
entirely new to the concepts of Object-Oriented programming.
I'm having a hard time geting the concept of 'objects', 'classes',
'why to use them', 'when to use them' etc. I have bought couple of
books on OOPS, but they dont tell me why I should use objects and not
the regular 'functions' or whats the diff. between the two.
I'm sure a lot of people out there would've had a similarly
frustrating experience when making the switch from Structural to
Object-oriented, like the switch from C to C++ or the first time OOPS
was introduced in Visual Basic or Perl. I'm interested to know about
your experiences during the transistion and what you had to do?
Also, for starters, I've made couple of home-grown definitions of what
I think are OOPS fundamentals. Could you please tell me if I'm on the
right track?
1. Objects are glorified functions:
Ojects are just like functions, as in, you have a code-block you think
might have to be repeated over and over again in your program. Might
as well write it once and keeping using it. Objects are these
code-blocks.
2. Objects are user-defined data-types:
Objects are just like int, float, double etc., but you get to define
them!
User defines what sort of data and its attributes an object has holds.
I know they are defined in a gazillion different ways but, is this a
good way to start? Did I miss any other fundamental concepts of
Objects?
Another thumb-rule I'm thinking of implementing till I get a hang of
the Objects: Always try to objectify every darn piece of executable
statement as a first resort.
Your comments, please.
Also, any books/URLs you'd recommend for the absolute beginner in
Objects( with reference to Java, especially).
Thanks for your time,
Reddy
- 10
- JSP Import CSV into databaseI'm looking to implement a feature into a JSP web app which will allow users
to import a CSV file into a database. My thoughts are that the process would
involve the following steps:
1) Transfer the CSV file from client to web server.
2) Have a simple Java application check folder location intermittently for
new files in upload folder on website
3) If a new file has been uploaded then parse the CSV into a collection of
JavaBeans
4) Use JDBC to import each JavaBean into table
My questions are the following:
- Is this the best way to achieve this (bearing in mind each row will need
to be validated)?
- What is the most appropriate method of tranferring a file to a JSP web
server?
- How should I transfer the JavaBean data to the SQL database - import each
bean one-by-one?
Any advice would be appreciated.
- 11
- BDK for J2SDK 1.4 onwardsDoes anybody know about BDK for J2SDK 1.4 onwards?
If yes please let me know the website or downloads
Regards
MAnjiri
- 12
- NIO slow (no buffering?)Hi!
I probably yet don't understand some fundamental things about NIO. The
following code is painfully slow (8sec. for a 6MiB file):
final FileChannel in = new FileInputStream( f ).getChannel();
final ByteBuffer token = ByteBuffer.allocate( 4 );
while( in.position() < in.size() )
{
in.read( token );
final String s = new String( token.array() );
token.flip();
}
What am I doing wrong?
- 13
- Layout in J2ME, MIDP 2.0Hi,
I wrote a little Midlet and want to have a StringItem and a TextField
next to each other, i.e. they should be in the same row. After
considering MID Profile I coded my Midlet as listed below.
So in my understanding they should be in the same row. The only
condition, which I cannot be sure of is "this Item has a LAYOUT_LEFT,
LAYOUT_CENTER, or LAYOUT_RIGHT directive that differs from the Form's
current alignment." (MIDP, class Form).
But how can I set the directive of a Form? Or did I misunderstand sth?
Why are the two items not in ONE row?
Thanks in advance!
Best regards, Franz
---BEGIN CODE---
public class Layout extends MIDlet implements CommandListener {
private Display display;
private Form form;
private Command EXIT;
public Layout() {
display = Display.getDisplay(this);
}
public void startApp() {
form = new Form("LayoutTest");
EXIT = new Command("Exit", Command.SCREEN, 1);
StringItem s1 = new StringItem("", "Eingabe:");
TextField tf1 = new TextField("", "", 20, TextField.ANY);
tf1.setLayout(TextField.LAYOUT_2);
form.append(s1);
form.append(tf1);
form.addCommand(EXIT);
form.setCommandListener(this);
display.setCurrent(form);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
public void commandAction(Command command, Displayable
displayable) {
if(command == EXIT) {
destroyApp(false);
notifyDestroyed();
}
}
}
---END CODE---
- 14
- Learn Java Programming Language Onlinehttp://learnjava.awardspace.com
This site includes JAVA lessons from the beginning to advanced level.
So this site appropiates for the beginner or non-basic of Java
language.
Guidelines:
1.Introduction 2.Fundamental Programming Concept 3.Decisions
4.Applets&Graphics 5.Introduction to Classes 6.Methods
7.Arrays&Vectors 8.Inheritance&Interfaces 9.Streams and Exceptions
10.Event Handling
- 15
- Persistent Cookies vs. session cookiesHi all (please excuse the crosspost but I can't find an HTTP group as such)
I am trying to find out the difference between persistent cookies and
session cookies. I have found plenty of documentation saying what the
differences are from the user point of view, but I want to know how the
server and browser distinguish between the two types in terms of HTTP
protocol.
I have read RFC 2965 and the Java servlet programming documentation and I
can't find any information as to how I should specify (or detect) whether a
specific cookie is persistent or session.
Any clues please?
Andy
|
|
|
