Please help-- need to populate a jtable at runtime

Question

Hello all,
i have this problem:
i have to populate a jtable at runtime.i take the data
from different buttons and from a jlist.i will focus
on the jlist here because the problem is elsewhere
after i select the particular items from the list i put them in a 2d array. the problem is that this array
might have null entries.for example, according to the
list item selections, my array might look like this:
data[0][0] = "somedata"
data[0][1] = ""
data[0][2] = "otherdata"
and so on
when i try to add row to the table it adds the
data[0][1] as well (tablemodel.addRow(data[0]);)
is there any way to make it not print the elements
that have null values?
the problem is that the number of rows and the number of columns of data is generated at runtime and it can be up to data[6][200] so if i only put data in say
data[45] and data[i][195] i only want to print
this values in the jtable's rows and not the whole
data[i]
i try to put the results of data[][] that are not null in a new array but it doesnt work.here is how i try to do this:
for (int i=0;i<data[0].length;i++) {
for (int b=0;b<data.length;b++) {
while (data[b][i] != null)
datanew=data;
when i try to add row datanew[b] in the jtable i see the same result (some columns are empty)
if i try to print data[b] i see something like "Ljava.jang.string:2@#435"
but if i print data[b][i] for the i's that are not null then i see the right results.
is there any way i can do it ?maybe exceptions handling? i dont know.
any kind of help would be greatly appreciated.
i am a begginer in java, i hope i dont sound ridiculous.
thank you in advance

Answer 1

thanks for your reply everybody
well i have changed the algorithm a little and now it works. however, i have a similar problem right now
as i said in the beggining the data will be selected both from a jlist and some buttons. now the list work.
the list has items that relate to buttons.
so now i have one more condition that will show only the
results of the list that relate to the buttons.
i have done this by using a boolean when each button is
selected.
the problem now is that i have an array that have null rows (instead of null columns that i had before)!!
even though i can add them to the jtable normally since
they are rows, i dont want to show empty rows.
so i want to create a new array that will have as rows
all the rows of the first array that contain data.
Here is my algorithm that generates data according to jlist and buttons selection:
Object[] selected_items = charList.getSelectedValues();
for (int j=0;j<selected_items.length;j++)
tablemodel.addColumn(selected_items[j]);
for (int k=1;k<data[0].length;k++){
if ( selected_items[j].equals(data[0][k]) ){
for (int b=0;b<=data.length-2;b++){
if (authors_boolean_array)
data3[b][j]=data[b+1][k];
else System.out.print("no author ");
else System.out.print("no ");
System.out.println("");
doesnt matter how it works. the result is that it ends
with a data3[b][j] array that can be up to data3[6][200]
and might have empty rows
so i want a new array say data4[][]
for example i need to find a way to do something like this:
data4[0][0] = data3[0][0];
data4[0][1] = data3[0][1];
data4[1][0] = data3[2][0];
data4[1][1] = data3[2][1];
i tried something like this: (count is the number of the selected buttons)
for (int j=0;j<selected_items.length;j++){
for (int b=0;b<=data.length-2;b++) {
if (data3[b][j] != null) {
for (int c=0;c<count;c++) {
for (int d=0;d<selected_items.length;d++) {
data4[c][d]=data3[b][d]; // (*)
else System.out.println("data4 null");
but it doesnt work because b isnt increased as need
at (*) line
well i know this is causing a hedaque so i wont be suprised if i dont receive any answer.however, since there are always some kind people arround i thought i could give it a try as it would save me precious time.
thank you all for your time