I have an object array like
Object[][] data2 ={
{" "," ",
" "," "," "," "},
{" "," ",
" "," "," "," "},
{" "," ",
" "," "," "," "},
{" "," ",
" "," "," "," "},
};
And I want to add
Object[][] data3 ={
{" "," ",
" "," "," "," "},
Is there an a way besides a hard coded for loop?
> I have an object array like
Good god, why!!?!?!?
> And I want to add
>
>
> > Object[][] data3 = {
> {" ", " ",
> " ", " ", " "," "},
>
>
> Is there an a way besides a hard coded for loop?
What do you mean "add"? You can't grow an array once it's created.
I have no clue what you're trying to do.
import java.io.File;
import javax.swing.JDialog;
import javax.swing.JFileChooser;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableModel;
import ModelParser.ModelParser;
public class CreateJTable extends JDialog {
//Data members
ReadFiles read;
String returnString=" ";
private boolean DEBUG = false;
public CreateJTable(){
read=new ReadFiles();
String location=runFileChooser();
File file=new File(location);
if(location!=null)
read.runLoad(file);
JTable table = new JTable(new MyTableModel());
for(int i=0; i<read.modelList.size();i++){
String model, brand, category, codeset;
int number;
model=(String) read.modelList.get(i);
brand=(String) read.brandList.get(i);
category=(String) read.categoryList.get(i);
codeset=(String) read.codeList.get(i);
number=i+1;
table.setValueAt(number, i, 0);
table.setValueAt(codeset, i, 4);
table.setValueAt(category, i, 1);
table.setValueAt(brand, i, 2);
table.setValueAt(model, i, 3);
}
JScrollPane scrollpane = new JScrollPane(table);
setSize(600, 600);
getContentPane().add(scrollpane);
setVisible(true);
}//end constructor
//File Chooser the Chooses Directory
private String runFileChooser() {
String location="";
JFileChooser fileChooser=new JFileChooser();
fileChooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
int returnVal = fileChooser.showOpenDialog(CreateJTable.this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
location = fileChooser.getSelectedFile().getPath().toString();
}
return location;
}
class MyTableModel extends AbstractTableModel {
private String[] columnNames = {"#",
"Category",
"Brand",
"Model",
"Code Set",
"Location"};
private Object[][] data = {
{" ", " ",
" ", " ", " "," "},
{" ", " ",
" ", " ", " ", " "},
{" ", " ",
" ", " ", " "," "},
{" ", " ",
" ", " ", " ", " "},
};
public int getColumnCount() {
return columnNames.length;
}
public int getRowCount() {
return data.length;
}
public String getColumnName(int col) {
return columnNames[col];
}
public Object getValueAt(int row, int col) {
return data[row][col];
}
/*
* JTable uses this method to determine the default renderer/
* editor for each cell. If we didn't implement this method,
* then the last column would contain text ("true"/"false"),
* rather than a check box.
*/
public Class getColumnClass(int c) {
return getValueAt(0, c).getClass();
}
/*
* Don't need to implement this method unless your table's
* editable.
*/
public boolean isCellEditable(int row, int col) {
//Note that the data/cell address is constant,
//no matter where the cell appears onscreen.
if (col >< 2) {
return false;
} else {
return true;
}
}
/*
* Don't need to implement this method unless your table's
* data can change.
*/
public void setValueAt(Object value, int row, int col) {
if (DEBUG) {
System.out.println("Setting value at " + row + "," + col
+ " to " + value
+ " (an instance of "
+ value.getClass() + ")");
}
//System.out.println(row);
//System.out.println( data.length);
if(row==data.length){
addRow();
}
data[row][col] = value;
fireTableCellUpdated(row, col);
if (DEBUG) {
System.out.println("New value of data:");
printDebugData();
}
}
private void addRow() {
Object[][] data3 = {
{" ", " ",
" ", " ", " "," "},
};
Object[][] data2 = new Object [data.length+1][data.length+1];
for(int i=0; i<data.length; i++){
for(int j=0;j<data.length;j++){
System.out.println(data[i][j]);
}//end second for
}//end for
}
private void printDebugData() {
int numRows = getRowCount();
int numCols = getColumnCount();
for (int i=0; i >< numRows; i++) {
System.out.print("row " + i + ":");
for (int j=0; j < numCols; j++) {
System.out.print(" " + data[i][j]);
}
System.out.println();
}
System.out.println("--");
}
}
}
Please tell me you didn't intentionally format that array like that.
If you have an array like this:
Object[][] array1 = {
{" ", " ", " ", " ", " ", " "},
{" ", " ", " ", " ", " ", " "},
{" ", " ", " ", " ", " ", " "},
{" ", " ", " ", " ", " ", " "},
};
You can assign another array to a part of the first like this:
Object[][] array2 = { array1[0] };
But those Object references would all be pointing to the same Objects. There wouldn't be any copying going on. If you really wanted to do that, it would be better to declare the 1d array separately, then build the 2d arrays off of those.
Object[] a1 = {" ", " ", " ", " ", " ", " "};
Object[] a2 = {" ", " ", " ", " ", " ", " "};
Object[][] array1 = { a1, a2};
Object[][] array2 = { a1 };
but if you want to have two arrays pointing to two different copies of the same data, then just create it with a loop, especially if it's really going to be filled with the same " " String.
Really, this is wat I'm trying to do:
private void addRow() {
Object[][] data3 = {
{" ", " ",
" ", " ", " "," "},
};
Object[][] data2 = new Object [data.length+1][data.length+1];
for(int i=0; i<data2.length; i++){
for(int j=0;j<data2.length;j++){
if(i><data.length){
data2[i][j]=data[i][j];
}
else{
data2[i][j]=data3[0][j];
}
}//end second for
}//end for
data=data2;
}
>
> You mean a linkedlist [][]?
You can use a LinkedList if you want, although an ArrayList is more appropriate for random access. If the number of columns doesn't even change, then you can use an ArrayList<Object[]>. If it will, then use an ArrayList<ArrayList><Object>>.
> Now I can't get the values back.
>
> > return data[row][col];
>
That's because you're still treating data as a 2d array, not a list of arrays.
> can be used and there is no
>
> data.get(int 1, int2);
If data is a List<Object[]>, then use data.get(int1)[int2];
> Now I can't get the values back.
>
> [code]
> return data[row][col];
> /code]
>
> can be used and there is no
>
> data.get(int 1, int2);
You know how to get the Nth element from a list, right? If not, see the API docs and if it's still not clear, see the collections tutorial.
Once you've got the Nth element from the list, what type is that? Object[]? List<Object>? Whichever type it is, you now know how to get it's Mth element.
How about adding objects?
Object[] a1 = {" ", " ", " ", " ", " ", " "};
private List<Object[][]> data;
public MyTableModel(){
data.add((Object[][]) a1);
}
ClassCast exception
Message was edited by:
blackmage
a1 is an Object[], not an Object[][].
You can't magically turn an object into something it's not by casting.
You didn't pay attention. List<Object[]>, not List<Object[][]>. Why would you want to add an extra dimension? The List replaces one of your Object[][] dimensions.
And a way to instantiate the object?
Object[][] a1 = {{" ", " ", " ", " ", " ", " "}};
private List<Object[][]> data;
public MyTableModel(){
data= new List();
//data.add(a1);
}
AGAIN: List<Object[]>, not List<Object[][]>
If you're trying to instantiate List, you need this:
http://java.sun.com/docs/books/tutorial/collections/
And if you don't understand the error message, you need this:
http://java.sun.com/docs/books/tutorial/
in particular, this:
http://java.sun.com/docs/books/tutorial/java/IandI/index.html
I understand the errors, I'm just not sure how do solve them.
like
Object[][] a2=new Object[row][col];
a2=(Object[][]) value;
data.add(a2);
//data.get(row)[col] = (Object[]) value;
fireTableCellUpdated(row, col);
trying to add a value to the list....2D arrays aren't the easy thing to work with.
> Its for creating an empty row in a JTable;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
class CreateEmptyRowDemo {
private JTable table;
public static void main(String[] args) {
new CreateEmptyRowDemo().go();
}
public void go() {
Object[] columnNames = {"a", "b"};
final DefaultTableModel model = new DefaultTableModel(columnNames, 1);
final JTable table = new JTable(model);
JScrollPane scrollPane = new JScrollPane(table);
JButton addButton = new JButton("Add Row >>");
addButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
model.addRow(new Object[2]);
}
});
JFrame frame = new JFrame(getClass().getName());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(scrollPane, BorderLayout.CENTER);
frame.add(addButton, BorderLayout.SOUTH);
frame.pack();
frame.setVisible(true);
}
}
~
> Object[][] a2=new Object[row][col];
> a2=(Object[][]) value;
For instance, you need to learn about references.
When you say a2=something, you're not copying an object into a2. You're copying a reference.
So in the above, you create a new Object[][], put a reference to it into a2, and then immediately abandon that newly created Object[][] by putting a different reference (that points to a different object) into a2.
> data.add(a2);
What's data and why are you adding an Object[][] to it? Is it List? Why are you still doing List<Object[][]> instead of List<Object[]> after being told at least three times?
> 2D arrays aren't
> the easy thing to work with.
Certainly not if you just try to plow ahead full steam without bothering to pay attention, study, learn, and understand.
Good luck. I don't have patience for this anymore.
