 |
|
Index ‹ java-programmer
|
- Previous
- 4
- HELP needed: Small Java applet I need a graphic Java applet that makes the following steps:
Given a circumference of radius "r",
Draw onscreen, say, 20 random radius.
Then, every time you press a button:
Rotate the 20 radius a given random angle (same for everyone).
Draw the new radius onscreen.
Note: The radius endpoints should be stored in float arrays and drawn as
float. (Of course one of the endpoints of every radius would be the center
of the circumference.)
I'm not very good at Java at the moment but I'd like to transform an old
program from QBasic into a java applet and I think that this little
framework is all I need. What I am getting at the moment is a lot of
compilation errors I don't understand.
The program I want to transform is here:
http://www.josechu.com/moving_fractal/index.htm
Thanks,
Josechu
- 4
- Playing (MIDI) sounds from Java applet (Shepard's Tones)
The applet for endlessly rising/falling scale
(auditory illusion)
on this page is fantastic!
http://www.cs.ubc.ca/nest/imager/contributions/flinn/Illusions/ST/st.html
How is this done?
(I'm assuming it uses MIDI.)
Is this sound applet playable from any
java-enabled browser on any Windows system?
How about on Mac or Unix?
I'm asking because I want to write
Java programs that plays simple
2-part inventions by Bach.
Thanks.
http://geocities.com/SOBlikeMIDIs/
__________________________________
Do you Yahoo!?
The New Yahoo! Shopping - with improved product search
http://shopping.yahoo.com
- 4
- java.sql.SQLException: Io exception: The Network Adapter could not establish the Hi,
I am sridhar, i have Oracle 10g express on my machine , when i am
trying to connect to Database via java jdbcAPI using Thin Driver , i
am getting the following Exception:
java.sql.SQLException: Io exception: The Network Adapter
could not establish the connection.
How can i resolve this problem,can any one give me the appropriate
solution.
Thanks
Sridhar
- 5
- converting between double and integerI have a variable declared as a double as :-
sValue = Math.floor(Math.sqrt(polynomialDegree));
where 'polynomialDegree' is an integer.
How do I convert 'sValue' to an integer?? I cant declare sValue as an
integer straight off because its returning an error message saying 'possible
loss of precision', and have tried to convert it to an integer using
intValue() but keep getting an error saying 'double cannot be dereferenced'
Where am i going wrong?
Thanks
- 5
- Creating tiled image from multiple tiff sources in JAIHi all,
My situation is as follows. I have a number of tiff files containing
adjacent tiles which I would like to combine into one image. Currently I
achieve this goal in the following manner using the Java Advanced Imaging
library:
1) Create a target TiledImage with attributes appropriate to hold all tiles.
2) Load each tiff file into a separate PlanarImage.
3) Get the Rasters of each of these PlanarImages and translate coordinates
according to the rectangle they must occupy in the target TiledImage
4) Invoke TiledImage.setData(Raster) with the translated raster for each
tile
This works ok, but it does not seem to take advantage of the JAI's
pull-model; image data is loaded into memory immediately, probably as a
consequence of the call to getRaster(). However I wish to defer the loading
of image data into memory until it is needed, because only a subset of all
tiles are two be displayed at any one time.
I hence believe I need something along the lines of the NullOpImage class.
Unfortunately, the constructor for this class only takes a single source,
while I need to be able to pass a source for each tiff tile. One solution is
to subclass NullOpImage (or its superclass, PointOpImage) and take care of
things myself. Is this the way to go about it, or is there a better and
easier solution?
Any suggestions will be greatly appreciated.
Regards,
Michael.
- 5
- Use of JVM id and Event Notifier patternIn our design for event subscription/publication, a JVM id is used to
identify the event channels (or event brokers). The JVM id refers to
an EventChannel on a host and there will be one EventChannel per host.
FYI, More information about Event Notifier pattern is available at:
http://members.ispwest.com/jeffhartkopf/notifier/
Is it okay to refer to JVM id (kernel level details) to identify a
user level class like EventChannel ? I feel that EventChannel should
be referred by some other way.
Any pointers will be appreciated.
B.
- 6
- EnterpriseBean and finalize()Hi Everyone,
I'm trying to learn EJB and picked up a copy of the book "SCBCD Exam
Study Kit" by Paul Sanghera. Inside it, I came across the following
sentence, which piqued my interest because I cannot see a) where this
can be found in the EJB 2.0 specification (actually, I was looking in
the J2EE 1.3 specification), or b) why finalizing a bean would be
interfering with the responsibilities of the container. Here's the
quote:
"... the bean class must not have any finalize() method because by
doing this you would be stepping on the container's toes, since it is
the responsibility of the container to manage the lifecycle, threads,
garbage collection, and so forth."
If anyone can shed a little light on this, and dispel the confusion,
I'd really appreciate it.
Many thanks,
Jono
- 6
- How to detect existing text tables in a hsql db?I have a Java-Application that creates several text-tables at the first
start. When I start the application again I just want to check, if the
text tables exist. But the application always returns a "false, table
does not exist" and the localdb.properties and localdb.script files are
written new. After that, the tables can be detected, but only until the
next start of the application.
dbcon.connect(LOCALDRIVER, LOCALPROTOCOL, LOCALDATABASE, LOCALUSER,
LOCALPASS);
DatabaseMetaData metadata = dbcon.con.getMetaData();
String[] aTyps = new String[]{"TABLE"};
ResultSet result = metadata.getTables(null, null, "%", aTyps);
while (result.next()) {
System.out.println(result.getString("TABLE_NAME"));
}
result.close();
Susanne
- 7
- Newbie Question - ArrayLists and methodsHello all (again),
My problem here is that I'm trying to build a list of ArrayLists that
hold data and I want to add the newly derived data into a table where
it's dependent on the first row. A short version of my program to
illustrate what I mean:
import java.util.*;
public class MyProg2 {
public static void main(String[] args) {
List table = new ArrayList ();
List <Integer> data = new ArrayList <Integer>();
data.add(1);
data.add(3);
data.add(4);
table.add(data);
System.out.println ("table(0) = " + table.get(0));
ArrayList <Integer> newNode = new ArrayList <Integer>();
newNode = createNode((ArrayList)table.get(0),0);
table.add(newNode);
System.out.println ("Added in a new row and table is now:");
System.out.println ("table(0) = " + table.get(0));
System.out.println ("table(1) = " + table.get(1));
} //end main driver
public static ArrayList createNode(ArrayList items,int lParen){
int a = 0; int b=0; int c=0;
if (items.size() >= 2){
a = Integer.valueOf(items.get(lParen).toString());
b = Integer.valueOf(items.get(rParen).toString());
c = a + b;
items.remove(lParen);
items.remove(lParen);
items.add(lParen,c);
}
return items;
}
}
(I'm unable to get rid of all the unchecked msgs because putting the
<Integer> tag sometimes made the program uncompilable. Use --nowarn
when you compile this program. :)
Iin this code, row 0 of table is changed in the method while it
creates row 1, but I don't understand why and don't know how to keep
it from changing. From this behavior, it's leading me to believe
ArrayLists are passed by value or is this the way of ArrayLists? I
thought parameters were passed by reference? What am I missing here?
-t
- 8
- Regex syntaxI have managed to form the regex for the following two:
CTL = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
String CTL_REGEX = "([[\\x00-\\x1F]\\x7F])";
LWS = [CRLF] 1*( SP | HT )
String LWS_REGEX = "((\r\n)??( |\\x09)+?)";
However, the following stumped me for hours.
TEXT = <any OCTET except CTLs, but including LWS>
String TEXT_REGEX = ...... // help me out please.
- 8
- Help! I don't know where to turn.> Then I went to java.sun.com and decided I have old packages and was
> going to upgrade everything. As far as I can tell, I downloaded the
> following:
>
> - the JS2E 1.5.0 (?)
> - the JDK
> - the JVM
> - the NetBeans 4.1 (?) bundle
> - the documentation tree
>
> So this seems hunky-dory. The problem now is two-fold:
>
> (a) I can't start the Java console anymore (I saw it once and it looks
> totally different than the previous version) though everytime I
> doubleclick the coffee mug icon in the Control Panel, it starts a new
> instance of javaw.exe.
> (b) Now my Mozilla Thunderbird 1.6 won't connect to my email server to
> retrieve my email.
>
> Can anyone provide some assistance or point me to the right place?
> Many thanks!
>
> Mike
If you have downloaded the J2SE 1.5.0 SDK (or the JDK 1.5.0) and ran
the installation, you do not need to install JVM (i assume you mean
JRE). The java console will look different if you have installed the
JDK.
I am not sure if you can keep two jdks installed. It is possible, but
if you want to save yourself frustation, uninstall the previous jdk
(and jre. Installing the jdk installs jre too along with it. :) ) and
install the new one.
Dont know about netbeans. Possibly, it needs the JAVA_HOME variable
set.
Also the documentation is totally separate. You just need to unzip to a
folder to read it, and not install. Its just a bunch of html files. Do
not worry about it. You can have as many docs of different versions as
you want.
Probably you messed up the internet settings so the problem with
thunderbird. nothing to do with java i suppose. not sure since i have
not used thunderbird yet.
- 9
- client server communication in java I have a java web service that returns byte arrays to the client.
First a byte array is returned and the server gets the acknowledgement,
then the next byte array is sent and so on. But I don't have much idea
how to implement it. How can I resume from where I stopped at the
server side? Can anyone give me some idea so that I can proceed?
- 15
- sourse & installationhere i'm for asking to u all that how can i install or download java
run time base running with console via internet.
- 15
- Which IDE to choose (more specific than earlier, very similar post)?Hello guys,
I'm C++/Windows programmer and I'd like to smoothly switch to Java. I read
replies to earlier, very similar post, but I didn't even hear about such
IDEs :-(
My question is following: using what IDE can I easily create applets with
controls like edit, list, combo boxes, buttons, tree controls and - this is
very important - have support to draw 3D graphics? Some time ago I was using
Borland JBuilder, but I guess it was not intended for building commercial
releases. I was browsing Sun Microsystems' site and found free "Sun Java
Studio Creator, Early Access". Can I create in it commercial applets using
features that I described above? If not, please advise me something free or
really good enough (read: easy to develop applets) to spend money IDE;
preferably free of course :-)
Generally I focused on "Sun Java Studio Creator, Early Access", but I'm
waiting for your replies.
Please reply, your opinion is crucial for me.
Regards
P.S. I'm not going to create server-side applets. I will be doing applets
run in web browser.
- 16
|
| Author |
Message |
Martin Cranna
|
 Posted: 2006-1-28 21:32:00 |
Top |
java-programmer, using import
I'm trying to import the Welomb class in the java divelog tutorial into
another application. But when I type import divelog.* it refuses
the absolute path for Welcome is
d:\Documents\Java\Divelog\src\divelog
the application I'm trying to import it from is at
d:\Documents\Java\Frames\src\frames
I've also tried creating a library (MyLibrary) and pointing to the
divelog.jar file and setting the classpath to point at divelog.jar. I've
then added the library to my project but when I try and create a Welcome
class it says it cant find the class. So neither using a library or
importing work.
I'm using sun java studio enterprise8 (free) does anyone know how to import
the divelog package into my app using an import statement.
I've tried the following with no success
import divelog.*
import Documents.Java.Divelog.src.divelog.*
in both cases I get package diesnt exist
any suggestion welcome!!
|
| |
|
| |
|
Roedy Green
|
| Posted: 2006-1-28 22:10:00 |
Top |
java-programmer >> using import
On Sat, 28 Jan 2006 13:32:28 -0000, "Martin Cranna"
<email***@***.com> wrote, quoted or indirectly quoted
someone who said :
>the application I'm trying to import it from is at
>
>d:\Documents\Java\Frames\src\frames
imports have nothing to do with where the files are, but what their
packages are called. The classpath deals with where they are.
see http://mindprod.com/jgloss/import.html
http://mindprod.com/jgloss/package.html
http://mindprod.com/jgloss/classpath.html
--
Canadian Mind Products, Roedy Green.
http://mindprod.com Java custom programming, consulting and coaching.
|
| |
|
| |
|
Martin Cranna
|
| Posted: 2006-1-29 5:19:00 |
Top |
java-programmer >> using import
Any idea how I tell sun's java studio enterprise to amend its classpath?.
I've tried adding a new library and giving it a valid classpath that way and
it doesnt work? At this rate I'm going to have to switch to just using an
editor and the basic sdk in preference to the $2000 IDE.
|
| |
|
| |
|
Martin Cranna
|
| Posted: 2006-1-29 5:39:00 |
Top |
java-programmer >> using import
In case anyone else has this problem I've found a solution. Firstly you use
import divelog.* in your source. As mentioned earlier this causes a no such
package error. Dont create a libary out of divelog and add the library to
your project, this doesnt work. Though I dont see why.
Do this instead
right click on the project.
Select properties.
Select Libraries. (whatever you do dont select sources)
Select Add Jar file.
Browse to your jar file (in this case divelog.jar) close everything and the
ide should now find the divelog package.
Is their a help group specifically about using various IDE's ?
Thanks to Roedy Green for putting me straight about imports. Because of the
way my IDE combines Application name and package name to produce a unique
path I thought the import statment must in some way also reflect the hard
disk path.
|
| |
|
| |
|
| |
|
Index ‹ java-programmer |
- Next
- 1
- Doing one last thing to a WeakReferenceLew wrote:
> Paul J. Lucas wrote:
>> Lew wrote:
>>>
>>> This is not a flaw in Java.
>>
>> Yes it is.
>
> No, it isn't.
Real compelling argument there. Java programmers need to stop being in denial
and admit that Java has flaws just like every other language.
- Paul
- 2
- Synth L&F as jarHello,
i am trying to build a L&F basedf on Synth but now i have problems
using the L&F in another project. I pack the L&F into jar add it to a
projects classpath but it is not possible to access the images
contained in the jar. I know that resources from a jar should be
accessed by:
MyResourceBase.class.getResource("path/relative/to/the/MyResourceBase.png")
the problem is that its not me who accesses the images but synth. AND
when i look into synths code the images should be loaded by:
new ImageIcon(url, null).getImage()
with url is the return of:
private URL getResource(String path) {
return _resourceBase.getResource(path);
}
That looks correct to me but it does not work. Has anyone build his
synth L&F and got it to work from a jar? If that does not work, what is
a custom L&F good for if it can not be deployed as a jar?
I am very thankfull for all hints
Harri E.
- 3
- AES-RijndaelI am doing an entry in the Java glossary on AES aka
Rijndael symmetric cipher.
I wonder if anyone knows of opensource Java implementations.
see http://mindprod.com/jgloss/aes.html
for what I have discovered so far.
--
Canadian Mind Products, Roedy Green.
Coaching, problem solving, economical contract programming.
See http://mindprod.com/jgloss/jgloss.html for The Java Glossary.
- 4
- Newbie:Please suggest ebook or any reading material for creating rich clients interfaces in javaWhile googling I found a very interesting presentation on creating
amazing GUI's in java on this link -
http://developers.sun.com/learning/javaoneonline/j1sessn.jsp?sessn=TS-3548&yr=2007&track=2
. I was very much impressed and really want to read and learn more on
developing such interfaces. So please suggest some reading material
for this.
I know core java and basics of swing.
Still learning java..:)
- 5
- Piped stream help.Hi Everyone,
I have two servlets that both need access to a data file. I would like to
have a 'driver' program that takes care of writing / reading objects to the
data file and i would like the driver program to be able to communicate
objects to each servlet. Can i do this w/ pipedinput / output streams? I do
not understand how i can reference a piped output stream in one object from
another!
TIA, Andrew.
- 6
- M-I 5-Persecution . my resp onse to the harass ment-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-= my response to the. harassment -=
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
My first reaction in 1990/91 was to assume that. if I broke contact then
they would not be able to follow and would lose interest.. So I did the
things that have been suggested by other people; I sold my. television,
stopped listening to the radio and tried. to withdraw away from the sources
of abuse as much as possible. I reasoned that. they must have more important
things. to deal with and that normal people would simply leave me alone if
it. were made difficult for them to continue their harassment.
I reckoned without the sheer vindictiveness of the abusers. They. did not
let up. but instead "got to" people around me, mainly people at work, to do
their dirty work for them. I went to see my GP, who refused to. believe what
he was being told, and. refused to direct me on to anyone who could be of
practical assistance. It was not until three. years had passed that the GP
admitted the matter was. outside his competence and suggested going to the
police.
In the summer of 1994 we called in. counter-surveillance experts from a
private detective agency to sweep our house and telephone for. bugging
devices. They conducted. a thorough search and found nothing; but as noted
above, since the existence of surveillance was being. forced in my face by
the harassers, you would expect. them to have taken the possibility of a
counter-surveillance sweep into account when. planning the type of devices
to. be employed.
In Easter 1995 I made a complaint to. my local Police station in London, but
the police have not expressed any intention to do anything about. the
continuing harassment ("we're not saying it's. happening and we're not
saying it isn't. happening" were the words used). I think the officer I
spoke to at Easter wasn't aware of it happening, although other members. of
the police force obviously do. know.
From April 1995 until the present time the. matter has been discussed in a
lot of detail on the Usenet (Internet) "uk.misc" newsgroup.. That discussion
has. given birth to the article which you are now reading. My hopes in
posting to Usenet were that. wider publicizing would discourage the security
services from continuing their harassment, and "draw. people out" into
concurring with the truth of what was being said. Neither of. those have
followed, but the discussion has served a purpose in allowing. this
structured. report to be created.
8322
- 7
- A specific external package import from javacWhich file(s) are required?
Where should these file(s) go?
What's the javac syntax to compile Test16 into ...\class\?
Given this directory structure:
C:\java\java\jTidy\Test16.java
C:\java\org\w3c\
C:\java\class\
Given that Test16.java has this import:
import org.w3c.tidy.Tidy;
SSCE @ <http://thufir.lecktronix.net/java/Test16.java>
Here's what I've gleaned from the 'net:
C:\java> javac -d . org\w3c\* C:\java\java\*
Clearly not correct, but that's my best effort at this point :(
thank you,
Thufir Hawat
- 8
- 9
- [OT] SourceForge AddReleaseTaskOfftopic: A question about HTTPS / Java:
I'm writing an Ant task to automate the SourceForge 'Add release' procedure.
For this I'm using Jakarta Commons Net and HttpClient.
The task can be used in an Ant build file as follows:
<taskdef name="sfaddrelease"
classname="org.xins.util.ant.sourceforge.AddReleaseTask"
classpath="xins-common.jar:commons-net.jar:commons-httpclient.jar"
/>
<sfaddrelease
user="znerd"
password="${password}"
file="build/xins-${version}.tar.gz"
group="71598"
package="71219"
release="${version}"
/>
The login is done using HTTPS. The Commons HttpClient library supports this.
But apparently, the server is not trusted, because I get a
javax.net.ssl.SSLHandshakeException. The message is:
"java.security.cert.CertificateException: Could not find trusted
certificate"
Apparently, I need to get the certificate of sourceforge.net and store it in
a keystore. Perhaps I should use 'keytool -import' for this, in some way.
Questions:
* How do I get the certificate of sourceforge.net?
* How do I store it in a file so that Java will accept it?
Ernst
_______________________________________________
email***@***.com mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-java
To unsubscribe, send any mail to "email***@***.com"
- 10
- Improving hashCode() to match equals()In my NamedBitField class I define equals() to mean that 2
NamedBitFields are equal if all 3 of their fields are equal.
Any suggestions for improving my hashCode() definition? I
can improve its performance by caching the computed hashCode
in a transient field, sure, but can I improve the _way_ it's
computed?
class NamedBitField {
String name; // name of bit field
int startIndex; // where it starts
int length; // how many bits it occupies
pubic boolean equals(Object obj) {
if (this == obj)
return true;
if ( obj == null || this.getClass() != obj.getClass() )
return false;
NamedBitField other = (NamedBitField) obj;
return
this.name.equals(other.name) &&
this.startIndex == other.startIndex &&
this.length == other.length;
}
public int hashCode() {
// to make this symmetric with equals() I'd prefer to
// involve all 3 fields (name, startIndex and length)
// in the computation of the hash. But how?
//
// Here I'm simply reusing String.hashCode(), but the
// hashed String at least incorporates the other
// fields
return ((name + startIndex) + length).hashCode();
}
}
Marco
----------------------------------------------------
Please remove digits from e-mail address (tr/0-9//d)
- 11
- AffineTransform.getScaleInstance questionHi,
I am using the AffineTransform.getScaleInstance to transform an image
by showing it growing. i.e. something like the following:
while(scale <= 1) {
repaint();
scale += 0.05;
try {
Thread.sleep(25);
}
catch(InterruptedException e) {
e.printStackTrace();
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setComposite(AlphaComposite.SrcAtop);
g2.transform(AffineTransform.getScaleInstance(scale, scale));
g2.fill(clipShape);
g2.dispose();
}
the problem is that the image grows large from the top lefthand corner
towards the bottom right hand corner.
What I want is the image to grow from the bottom left hand corner to
the top right hand corner.
I have tried messing with the Scale instance, but I cant seem to figure
it out.
anyone know how to do this? thanks!
- 12
- JSP, forward, include, dispatch rules ?Can I get a clear summary of the rules involved with these ?
forward, include, RequestDispatcher rd
<jsp:include page="servlet/MyServlet" flush="false" />
rd.forward(req, res);
<jsp:forward page="NextPart.jsp" />
response.sendRedirect("NewPage.html");
What I have seen, is that this Error occurs:
'IllegalStateException: Cannot forward after response has been
committed'
When a JSP/Servlet writes to the page using a PrintWriter and then
tries to do a forward.
Maybe the following also cause problems:
response.setContentType(...)
response.setHeader(...)
TIA for your help, suggestions; Please Advise.
- 13
- JTree with dynamically adjusted row height during editing.I have extended JTable so that the installed editor for a cell checks
at each keystroke whether it must adjust the row height in order to fit
the content in the cell. This is easy to do with a document listener
which just starts a thread on each insertion to check for a height
change, and then calls setRowHeight on the appropriate row.
However, it does not seem to be so simple to do the same thing with a
JTree. setRowHeight cannot be called on a specific row, and with
rowHeight set to 0, the tree cells are only resized when the tree
manager itself queries the height. There does not appear to be a way
to get the editor to do this directly.
Does anyone know how to get this effect? It allows for something much
like a regular text outliner using JTree and I would think lots of
people would have wanted to do this in the past, but I havent found
evidence that it has been done.
- 14
- JNI: call C-main program from JavaI have a C-program which calls Java functions through JNI.
The C-part runs okay, and I want to debug the Java code.
For that reason, I want to start the Java debugger and then start the
C-main program through JNI. After that I hope I can set
breakpoints within the Java part and start debugging.
In the documents I saw that "System.LoadLibrary()" can load
only DLL's and shared object, but no main-program.
Thanks for any help,
Josef
- 15
- McNealy should have watched "Godfather 3" -- "Never hate your enemies, it clouds your judgement.""The worst thing about this deal is that Sun brought it upon itself
through a campaign of ridicule and hate promulgated personally by CEO
Scott McNealy. This is McNealy's failure and nobody else's. The quotes
last week from McNealy were laughable, the about face nothing short of
shameful. How are Sun's big customers going to believe what the company
says in the future in the face of such a change? How can they base huge
technical investments on the word of Sun?"
Answer: They can't. They never could.
http://www.pbs.org/cringely/pulpit/pulpit20040408.html
|
|
|
