How to implement tablemodel in java? - java

I am new with JAVA. I have started using JTable. I could not understand how to use tablemodel with JTable. Objective is to understand the use of tablemodel.

As it's name suggests... the TableModel is a model for the table. The JTable is a generic utility which can display data from any source. By implementing a concrete TableModel you are giving the JTable all it needs to populate itself.

Related

relationship with ArrayList and jTableModel

Hej.
There is a collection with data.
static ArrayList<MyBeans> all = new ArrayList<MyBeans>();
There is a jTableModel too which invoke this table on jFrame.
TableModel model = new Table(all);
JTable table = new JTable(model);
For example, at some moment ArrayList<MyBeans> all was changed. What should do for change this table too?
If your all ArrayList<MyBeans> (which by the way should not be static) is the nucleus of a TableModel, then your problem is that you're trying to make changes directly to the ArrayList which you should never do. Instead you should make changes only by calling public methods in your TableModel, and these methods should fire the appropriate AbstractTableModel notification method that will notify any registered listeners (here, the displayed JTable itself) of any changes to its model.

Which editing and removing row method is better for JTable?

I wanna ask that which method to edit a JTable is better than the other?
use setValueAt() function.
Make a new model of JTable and feed its object to JTable.
And also, how to remove a Row from JTable without using method 2 described above?
You would use the setValueAt method when you're changing one value at a time.
You would make a new TableModel when you're changing 25% or more of the rows at one time.
If you use a DefaultTableModel as your TableModel, you can use the addRow or setValueAt methods to add a row and change a row value. You can use the removeRow method to remove a row.
Since the TableModel is associated with the JTable, any changes to the TableModel are reflected in the JTable. Any changes to the JTable by the user are reflected in the TableModel.

huge JTable AbstractTableModel remove all rows

java JTable, Say I have a huge JTable (800*50) with AbstractTableModel. Now I want to remove all table rows and put new data rows into that table. Which way is easiest and high-performance way to achieve this ?
Thanks.
The AbstractTableMoeel doesn't support this. If you extend the AbstractTableModel to create a custom model then you need to implement this method yourself.
Or you can use the DefaultTableModel which implements a setRowCount() method. So you can reset the rows to 0. You can then use the insertRow(...) method to add new rows.
However the easier way is to probably just create a new TableModel. Then you can refresh the table by using:
table.setModel( newlyCreatedModel );

Problem in giving input to JTable from keyboard

I want to know how to give input to the cell in a jtable from keyboard.
And when I try to do this when I move on to next cell the previous enter data is removed or erased automatically.
I am using abstracttable model for creating jtable.
iam using abstracttable model for creating jtable....
and when i try to do dis when i move on to next cell the previous enter data is removed or erased automatically....
The AbstractTableModel doesn't implement the setValueAt(...) method. So unless your custom model implements this correctly you will lose the data entered in the editor.
I suggest you keep it simple and use the DefaultTableModel until you better understand how a JTable works. The code would be:
DefaultTableModel model = new DefaultTableModel(...);
JTable table = new JTable( model );
As discussed in How to Use Tables, you can specify a renderer and editor for each column in a JTable, or you can override getColumnClass() to obtain the default for any of the listed data types. In addition, you might compare what you're doing with one of the examples listed there or edit your question to include an sscce.
Sounds like you are not saving the data entered into your model. Secondly, I would suggest extending DefaultTableModel instead of AbstractTableModel unless you have a good reason.

Working with data and a JTable?

I have a JTable that I want to use to display some data (a String and a Boolean in each row). The data is maintained by my own class. Is there some way to bind the data model to the JTable, so that when I add to the model, the JTable is dynamically updated and when I remove something from the model, the row is removed from the JTable?
I have previously worked with Flex and Actionscript, and this is very easy to do there with data binding, so I'm just wondering how it's done in Java.
Thanks.
You will need to have your dataset implement the TableModel interface. if you do that then you can apply it to the JTable. If you extend AbstractTableModel you will inherit some event firing methods that your table will handle and will update the view. see this tutorial. Note that the default implementation of JTable will renderer your data for you, and if a Boolean is found, it will show up as a check box.
You'll probably find both the Java JTable tutorial and the JTable API documentation helpful in understanding how JTable works, but otherwise here's a quick rundown.
The premise of a JTable is that it is paired with an object that implements the TableModel interface, which by default is an instance of DefaultTableModel. The table model object is made up of a list of columns, each of which has its own data type (String and Boolean in your case), and a list of rows containing the actual data for the table.
Whenever the JTable is drawn by the swing drawing code, it repeatedly calls the method:
public Object getValueAt(int row, int col)
Thus, when you add data to the table model, it is always rendered as you expect in the next screen refresh (dynamically).
The only thing you really need to worry about, then, is getting the data from your object into the table model and back out again. Other than that, JTable takes care off all the heavy lifting.
While implementing TableModel is easy enough for simple cases, you might want to consider a true binding approach (my favorite is Glazed Lists - watch the 30 second video on how easy this is and you'll be won over). Beans Binding (now Better Beans Binding) also has an implementation of observable lists that might be useful (although I much prefer the Glazed Lists approach)

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