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ulvi ugur

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since Aug 05, 2003

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Recent posts by ulvi ugur

NullPointerException for bean on a JSP page

Hi All,

I use a jsp page with beans and receiving a NullPointerException when I call the page. It behaves like my bean ("localityJDBCTemplate") is not initialized. I thought it was done here :

Relevant lines from my code are below.

Example.jsp :

Beans.xml :

8 years ago

EJB and other Jakarta /Java EE Technologies

JSP page with Bean throws : NullPointerException

Hi All,

I use a jsp page with beans and receiving a NullPointerException when I call the page. It behaves like my bean ("localityJDBCTemplate") is not initialized. I thought it was done here :

Relevant lines from my code are below.

Example.jsp :

Beans.xml :

8 years ago

eclipse Step-Filtering

Hi All,

I use eclipse for a API development project. As usual, I added the API libraries as jars into my (Java Build Path->Libraries).

The problem is that when I start runnung the application in debug mode, it stops on a thread which refers to the API code with 2 symptoms :

1- It says "Source not found" in the Class File Editor and expects me to "Attach Source".
2- It shows a Thread Suspended in the Debug Window with a NullPointerException

In order to get rid of the first issue, I added the API packages in the Preferences->Java->Debug->Step Filtering step. This didn't work !

In order to adress it over the exception, I disabled "Suspend execution on uncaught exceptions" parameter. This didn't work either !

Any ideas how one can resolve this issue ?

Cheers,

Ulvi

12 years ago

Other IDEs, Version Control

JTabbedPane.removeAll() throws java.lang.IndexOutOfBoundsException

Good one Michael

Figured it out myself, two events happenning at the same time and two different threads try to remove the tabs in a race condiition.

Sorry for the false alarm and thanks for the attention.

CHeers,

Ulvi

14 years ago

Swing / AWT / SWT

JTabbedPane.removeAll() throws java.lang.IndexOutOfBoundsException

Hi Guys,

My JTabbedPane.removeAll() throws java.lang.IndexOutOfBoundsException; should one handle this in a try/catch or is there a better way to do this that no exceptions are thrown ?

Cheers,

Ulvi

14 years ago

Swing / AWT / SWT

JSpinner does not work for Numbers

Hi Guys,

I tried Ernest's path and used the constructor with Comparables but this time it started throwing casting exceptions about Byte and BigInteger which told me that I have to go either in the src from JDK or do my own stuff.

Thanks Rob, that was a good advice, generating another class for this feels a bit of an overkill but totally made sense compared to this "casting chaos".

Thanks and cheers,

Ulvi

14 years ago

Swing / AWT / SWT

JSpinner does not work for Numbers

Hi,

Can you please have a look at the following code to figure out why my customer JSpinner throws a runtime "java.lang.ClassCastException: java.math.BigDecimal cannot be cast to java.lang.Integer" error ?

import java.awt.*;
import java.math.BigDecimal;
import java.text.NumberFormat;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import javax.swing.*;
import javax.swing.text.DateFormatter;
import javax.swing.text.DefaultFormatterFactory;
import javax.swing.text.NumberFormatter;
public class MyNumberSpinner extends JSpinner {
SpinnerModel model = null;
JComponent editor = null;
public void initialize(BigDecimal initialValue, int dps) {
double precision = Math.pow(10, dps);
double stepSize = 1.0 / precision;
model = new SpinnerNumberModel(initialValue, 0, 1000000.0, stepSize);
StringBuffer bf = new StringBuffer("####0.");
for (int i=0; i<dps;i++) {
bf.append("#");
}
NumberFormatter fm = new NumberFormatter(new DecimalFormat("bf"));
JFormattedTextField txt = new JFormattedTextField(fm);
this.setModel(model);
this.setEditor(txt);
}
public static void main(String[] args) {
Frame test = new Frame("TEST");
test.setSize(200, 100);
test.setLayout(new BorderLayout());
MyNumberSpinner tmp = new MyNumberSpinner();
tmp.initialize(new BigDecimal(12.475), 3);
JPanel conten = new JPanel();
conten.add(tmp);
test.add(conten, BorderLayout.CENTER);
test.setVisible(true);
}
}
Thanks in advance,
Ulvi

>

14 years ago

Swing / AWT / SWT

declarations with <> operator with classes like S , T , K, V, M, B

Thanks guys, very helpful !

14 years ago

Java in General

tablecelleditor doesn't call setvalueat

Hi There,

I use comboboxes within my JTable. If I use the DefaultCellEditor, it calls the setValueAt() method of my TableModel perfectly so that I can change the content of my model.

However, if I use my custom TableCellEditor, it doesn't call the setValueAt() method.

Any idea how I can "convince" my TableCellEditor to call setValueAt() when its value changes ?

Thanks in advance,

Ulvi

14 years ago

Swing / AWT / SWT

declarations with <> operator with classes like S , T , K, V, M, B

Hi Bear,

I am actually using generics for collections to declare the content of it but what do these single letters mean ? Are they real classes or is it just a dummy identifier to be replaced with a real class ?

Cheers,

Ulvi

14 years ago

Java in General

declarations with <> operator with classes like S , T , K, V, M, B

Hi all,

Can anybody tell me what the below conventions are called and with which version of Java the are introduced :

or better with a question mark (?)

Thanks in advance,

Ulvi

14 years ago

Java in General

ConcurrentModificationException during ObjectOutputStream.writeObject()

Hi,

I need to come back to this one again !!

The proposal didn't solve the problem again. I changed it to :

but that didn't help either. I am still getting these "java.util.ConcurrentModificationException". Any further suggestions ?

Thanks in advance,

Ulvi

15 years ago

Threads and Synchronization

ConcurrentModificationException during ObjectOutputStream.writeObject()

Thanks Travis ! As this problem only occurs very occasional, I will update this thread later to verify that the solution works.

15 years ago

Threads and Synchronization

ConcurrentModificationException during ObjectOutputStream.writeObject()

Hi All,

I have this multi-threaded application writing on the socket in a sequence and processing data and writing again. Here is a short code snippet :

Here queue is a LinkedBlockingQueue and outputMsg is an encapsulation of a HashMap. Now, the problem is, this is throwing ConcurrentModificationException on the writeObject() method. Synchronizing on outputMsg didn't really solve the problem.

Any ideas you can share with me about this interesting subject ?

Thanks in advance,

Ulvi

15 years ago

Threads and Synchronization

Java Application-JDBC Pooling-Performance Boosting

Hi,

After some weeks, I can answer my own post; more connections simply increase the performance there. Running 50-60 simultaneous connections in multi-threads increased our performance like 30-40 times.

Thanks for the replies anyways.

Ulvi

15 years ago

JDBC and Relational Databases