I am working on a GUI application in Java for a client. One of the parts of that GUI needs to upload about a 1000 records each having 17 attributes simultaneously(i.e. it needs a 1000 X 17 table). Now Netbeans IDE 7.2.1 allows at most 100 rows at a time in a Jtable. Any suggestions how can i make one for displaying 1000 entries at a time. I considered having 10 tables one after other but that will leave a very messy coding to be done later at the back end!
Don't use an IDE to create your GUI. The IDE generates terrible code that creates a table with the null values for the number of rows that you want to create.
There is no restriction on the number of rows a table can hold. If you create the code manually you can do something simple like:
DefaultTableModel model = new DefaultTableModel(columnNames, 0);
JTable table = new JTable(model);
which will create an empty table with the column names that you specify
Then you can add rows individually using the DefaultTableModel.addRow(...) method.
Or you can add all the rows at one time by using the DefaultTableModel.setDataVector(...) method.
You can create your GUI with any IDE you like. There is no problem with Netbeans in this area. Netbeans, like any other editing tool, allows you perfectly well to create some class like i.e. MyModel that extends an AbstractTableModel, which has no GUI and you should use in order to separate your Model from the View and Controller that have a GUI.
Your JTable will then automatically call getValueAt(row, col) and getRowCount() in order to show the tiny subset of your 1.000 or maybe 1.000.000 lines that need to be displayed.
You must not necessarily load all 1000 records to any Vector or ArrayList. Just make getValueAt(row, col) read each row and return every column.
There is a high probability that your user will not scroll down every time and will not ask the TableModel to provide anything more than the 40-60 lines that should be visible after the first rendering.
This example shows the getValueAt, used on a scrollable ResultSet sr from a database:
#Override
public Object getValueAt(int row, int column) {
try {
sr.absolute(row + 1); // position your ResultSet.
switch (column) {
case 0:
return sr.getInt("...");
case 1:
return sr.getString("...");
case 2:
return sr.getString("...");
case 3:
return ......
default:
return ("-");
}
} catch (SQLException sex) {
........
}
}
This is what happens at the GUI side:
Is the JTable. Since you use a TableModel it will show you the JTable only at runtime.
Here is the place that allows you to bind your model to the auto-generated code of NetBeans.
This is the instance of your model. You could also write something like "new MyModel()" here.
The generated code is no monster either:
...
jTable1.setModel(etb);
jTable1.setSelectionMode(javax.swing.ListSelectionModel.SINGLE_SELECTION);
jTable1.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
myMouseClicked(evt);
}
});
jScrollPane1.setViewportView(jTable1);
...
Related
at the moment I have an app that allows me to display data in a Jtable and then when I double click the Jtable this open a little window to edit only 3 fields, comments, expiration date and description. I update the this values (whit a preparedStatement) the thing is that everytime that I make an update to the database my table just refresh itself, changing the dateFormat with the new value that I've just inserted in my other window but with a different format!. How is this possible?
I' don't understand this because the only I only set a model to the table when I press my "search" button which contains the following code:
ArrayList<FiltrosResumen> filtrosResumenList = MainFrame.dataBase.searchFiltroResumen(query);
FiltrosResumenTableModel resumenModel = new FiltrosResumenTableModel(filtrosResumenList);
this.resumenTable.setModel(resumenModel);
hideColumns(1);
I'm using a custom table model containing all the table Fields, so first as you can see I colect all the rows from the database into a ArrayList from a custom object "FiltrosResumen", then I pass this to the constructor from my customTable model "FiltrosResumenTableModel" which extends AbstractTableMode I'm not using any special renders the most important methods are
public Object getValueAt(int rowIndex, int columnIndex) {
switch (columnIndex) {
case 0:
return this.filtrosResumen.get(rowIndex).getIdFiltro();
//....
//case 9:
default:
return null;
}
}
public void setValueAt(Object aValue, int rowIndex, int columnIndex) {
FiltrosResumen filtroResumen = new FiltrosResumen();
switch (columnIndex) {
case 0:
filtroResumen = this.filtrosResumen.get(rowIndex);
filtroResumen.setIdFiltro(Long.parseLong(aValue.toString()));
this.fireTableCellUpdated(rowIndex, columnIndex);
break;}
//....
//case 9:
}
And the constructor
public FiltrosResumenTableModel(List<FiltrosResumen> filtrosResumen) {
this.filtrosResumen = filtrosResumen;
}
And as I stated before, the database does not interact directly whit the table since storing the query result in a ArrayList, and then sending this to the constructor of my customTableModel.
EDIT: In order to change the value from one of the rows items I send a FiltrosResumen Object in this way:
FiltrosResumenTableModel modelo = (FiltrosResumenTableModel) this.resumenTable.getModel();
resumen = modelo.getResumen(row);
EditResumenIF editConexionesIF = new EditResumenIF(resumen);
EDIT: Passing a the resumen object to a InternalFrame Constructor (EditResumenIF).So in this new InternalFrame (EditResumenIF) I assign the values to a JCalendar and a JTextField to change the values and then save them. Afther the same object received by the constructor to a method that does the query and then return a string, ( if the string it's empty it' means that the query was successful without any mistakes)
String error = MainFrame.dataBase.updateResumen(resumen, resumen.getIdFiltro());
How comes that my Table knows that the value changed?
The default renderer for a cell of type Object.class is "a label that displays the object's string value." Unless your implementation of TableModel override's getColumnClass() to return some other value, your result is not unexpected. You might compare this example using DefaultTableModel to your implementation.
Addendum: How does my table know that the value changed?
JTable is a TableModelListener; any change to the model is (or should be) propagated to the table. Absent a complete example, I'm guessing that you are using a second table, table2, to edit a copy of certain data obtained from the original, table1.
Verify that you are copying the data in getResumen() and not just copying a reference to the table1 model.
In your implementation of setValueAt() in the TableModel of table2, update the model of table1. The exact mechanism depends on your TableModel; two approaches are contrasted here.
Addendum: I'm not using another table…I'm passing a reference to my internal frame.
The same principles would apply. As an alternative to directly coupling the models, let the table's model be a PropertyChangeListener to the internal frame, as shown here.
I am facing problem of duplicate rows in the JXTable. If I sort the JXTable data while the new rows are being inserted in JXTable, the final result in JXTable shows duplicate rows that make invalid result in table. Even it also shows correct count of rows that has been inserted but some rows are completely missing whereas some rows are found duplicate in JXTable.
If I sort the JXTable after all data has been inserted successfully then it is showing correct data i.e no duplicate rows and no rows missing.
code example :
I have a method to which I am passing defaultTableModel and here is am adding items in the table
public void addingItems(DefaultTableModel defaultTableModel)
{
for(int i=0;i< numberofItems;i++){
Vector vobject = new Vector();
vobject.add("...");
vobject.add("xxx");
vobject.add("yyy");
...
..
vobject.add("");
defaultTableModel.addRow(vobject);
}
one the other hand I have adding code of sorting at tableHeader actionlistener
tableheader.addMouseListener(new MouseListener() {
public void mouseClicked(MouseEvent e) {
Vector data = defaultTableModel.getDataVector();
Collections.sort(data, new ColumnSorter(colIndex, ascending));
}
});
I have put code in the synchronized block but not getting success.
Please provide a better solution to handle this issue.
I have put code in the synchronized block but not getting success.
Because you have to handle synchronization not only in your sort handler block, but also on each modification operation.
For example:
...
vobject.add("");
synchronized(monitor) {
defaultTableModel.addRow(vobject);
}
}
and
...
Vector data = defaultTableModel.getDataVector();
synchronized(monitor) {
Collections.sort(data, new ColumnSorter(colIndex, ascending));
}
}
In this case your UI could look somewhat unresponsive if you have a lot of data in your table because sort is N^2*logN. If you have somewhat about 200 entries - it wouldn't make a problem for you.
I have question that how can I delete all datas from my jTable in GUI when a user entered a key?
thanks
You can set a new empty data model:
TableModel newModel = new DefaultTableModel();
jtable.setModel(newModel);
You need to understand that a JTable is a view of the data, while the actual data resides in the TableModel. If you need to clear out the table, then you need to clear out the TableModel.
If your TableModel is an AbstractTableModel, you must provide implementations of 3 methods:
public int getRowCount();
public int getColumnCount();
public Object getValueAt(int row, int column);
Frequently the actual data objects are stored in an additional data structure (e.g. a list), and then the AbstractTableModel queries that list.
List<DomainObject> objects = new ArrayList<DomainObject>();
public int getRowCount() { return objects.size(); }
// How many columns you make depends on what features of the objects you're exposing.
public int getColumnCount() { return NUMBER_OF_COLUMNS; }
public Object getValueAt(int row, int column) {
DomainObject object = objects.get(row);
... // pull out the property based on the column they pass in
}
// By exposing this method, you can allow your Controller code to reach into this model
// and delete all the rows.
public void clear() {
objects.clear()
}
What HH is suggesting you do is change the model of your JTable to reference an empty model, which will in effect clear out the table. However, the columns etc. will not be persisted correctly (the new DefaultTableModel has no idea what those column names would be).
After you've researched how the view and model fit together more, take a look at GlazedLists. It allows a very powerful way to create TableModels which provide dynamic views of your data, e.g. by filtering out rows that do not match certain criteria.
To sum up - you're not going to find a method on the JTable to clear out its contents, because that's the job of the TableModel. You need some way of ensuring that the TableModel's backing data structures are cleared out.
If you are using the DefaultTableModel then you can just use:
model.setRowCount(0);
This is better than creating a new DefaultTableModel. Creating a new TableModel causes the TableColumnModel to be recreated, which means all the TableColumns will be resize to default values and recreated in the order in which the columns exist in the model. The user may have changed these properties and shouldn't be forced to do it again.
If you are just deleting certain rows that contain a particulsar value, then you can use the DefaultTableModel.removeRow(...) method. Make sure you start by deleting row from the end of the model and count down to 0.
call removeAll of j_table method at addActionListener
button1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
j_table.removeAll();
data_model_table.setRowCount(0);
}
});
There is a jbutton in my Jpanel. When I clicked it, it loads up my Jtable, sometimes a query return so many records (500 rows). So I want to restrict it to 5 records.
When query return I want to count it; if it's higher than 5 then Jtable shows up only first 5 record, when user click Forward button it will shows up next 5 record. When user click Back button it will show previous 5 record.
How can I do this? Is there any example for this with TableModel?
I suggest implementing a "Paged" TableModel which provides a window onto the entire dataset and methods for moving forwards and backwards throughout the data. This way you do not require two Lists to store the data but rather a single List holding all data along with a marker to your current position; e.g.
public class ImmutablePagedTableModel extends AbstractTableModel {
private final List<MyBusinessObject> allData;
private final int pageSize;
private int pos;
public ImmutablePagedTableModel(List<MyBusinessObject> allData) {
// Copy construct internal list. Use ArrayList for random access look-up efficiency.
this.allData = new ArrayList<MyBusinessObject>(allData);
}
/**
* Returns true if the model has another page of data or false otherwise.
*/
public boolean hasNextPage() {
return pos + pageSize < allData.size();
}
/**
* Flips to the next page of data available.
*/
public void nextPage() {
if (hasNextPage()) {
pos += pageSize;
// All data in the table has effectively "changed", so fire an event
// causing the JTable to repaint.
fireTableDataChanged();
} else {
throw new IndexOutOfBoundsException();
}
}
public int getRowcount() {
return Math.min(pageSize, allData.size() - pos);
}
// TODO: Implement hasPreviousPage(), previousPage();
}
As 00rush mentions a more ambitious approach would be to use a SwingWorker to stream in the data in the background. You could still use the paged TableModel approach for this; you'd just need to ensure that appropriate TableModelEvents are fired as you append to the end of the allData list.
If you wish to load a large table, you may want to use a SwingWorker (details here) thread to load the table in the background. Loading a table with 500 rows should not be a problem. You can then put the data into a suitable object format and pass it to your TableModel.
If you decide to use a List for example, in your table model you could have two lists:
List allData
List viewData
int startIndex
The viewData list is what is referenced by the getValueAt(..) method in your implementation of the TableModel interface. The viewData list is always a subset (bound by startIndex, of length 5) of allData. When the user clicks "Next", your action listener could call a method on the Table model that increments startIndex by 5 (or whatever). You then regenerate your viewData instance so that it is the appropriate 5 row subset of allData, and call fireTableChanged(). This will be easy if you have extended AbstractTableModel in the first place.
This should be pretty straightforward to implement. I think its better than making a database call every time you want to get the next set of data. IMHO, its better to take a little bit more time upfront to preload the data.
We're seeing JTable selection get cleared when we do a fireTableDataChanged() or fireTableRowsUpdated() from the TableModel.
Is this expected, or are we doing something wrong? I didn't see any property on the JTable (or other related classes) about clearing/preserving selection on model updates.
If this is default behavior, is there a good way to prevent this? Maybe some way to "lock" the selection before the update and unlock after?
The developer has been experimenting with saving the selection before the update and re-applying it. It's a little slow.
This is Java 1.4.2 on Windows XP, if that matters. We're limited to that version based on some vendor code we use.
You need to preserve the selection and then re-apply it.
First of all you will need to get a list of all the selected cells.
Then when you re-load the JTable with the new data you need to programmatically re-apply those same selections.
The other point I want to make is, if the number or rows or columns in your table are increasing or decreasing after each table model reload, then please don't bother preserving the selection.
The user could have selected row 2 column 1 having a value say "Duck", before model updation. But after model updation that same data can now occur in row 4 column 1, and your original cell row 2 column 1 could have new data such as "Pig". Now if you forcibly set the selection to what it was before the model updation, this may not be what the user wanted.
So programmatically selecting cells could be a double edged sword. Don't do it, if you are not sure.
You can automatically preserve a table's selection if the STRUCTURE of that table hasn't changed (i.e. if you haven't add/removed any columns/rows) as follows.
If you've written your own implementation of TableModel, you can simply override the fireTableDataChanged() method:
#Override
public void fireTableDataChanged() {
fireTableChanged(new TableModelEvent(this, //tableModel
0, //firstRow
getRowCount() - 1, //lastRow
TableModelEvent.ALL_COLUMNS, //column
TableModelEvent.UPDATE)); //changeType
}
and this should ensure that your selection is maintained provided that only the data and not the structure of the table has changed. The only difference between this, and what would be called if this method weren't overridden is that getRowCount() - 1 is passed for the lastRow argument instead of Integer.MAX_VALUE, the latter of which acts a signifier that not only has all the data in the table changed but that the number of rows may have as well.
I had the same issue in an application. In my case the model in the table was a list of objects, where the object properties where mapped to columns. In that case, when the list was modified, I retrieved the selected index and stored the object that was selected before updating the list. After the list is modified and before the table is updated, I would calculate the position of the selected object. If it was still present after the modification, then I would set the selection to the new index.
Just setting the selected index in the table after the modification will not work, because the object may change position in the list.
As a side note, I found that working with GlazedLists makes life much easier when dealing with tables.
This is default behavior. If you call fireTableDataChanged() the entire table is rebuild from scratch as you set entirely new model. In this case the selection is, naturally, lost. If you call fireTableRowsUpdated() the selection is also cleared in general cases. The only way is to remember selection and then set this. Unfortunately there is no guarantee that the selection will be still valid. Be careful if restoring selection.
for reference, as #Swapnonil Mukherjee stated, this did the trick with a table with selectable rows:
// preserve selection calling fireTableDataChanged()
final int[] sel = table.getSelectedRows();
fireTableDataChanged();
for (int i=0; i<sel.length; i++)
table.getSelectionModel().addSelectionInterval(sel[i], sel[i]);
If I recall correctly, saving selection and re-applying it is what we have done too...
I was facing same issue and when tried to search the reason I got this question but it seems a bug in Java SDK. http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4276786
WORK AROUND
A temporary work-around is available. It should be removed once this bug is fixed as it's suitability has NOT been tested against fixed releases.
Use this subclass of JTable.
Note: This is for the MetalLookAndFeel. If using other look and feels, the inner FixedTableUI subclass will have to extend the TableUI subclass for that look and feel.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.event.*;
import javax.swing.plaf.basic.*;
public class FixedTable extends JTable {
private boolean isControlDownInDrag;
public FixedTable(TableModel model) {
super(model);
setUI(new FixedTableUI());
}
private class FixedTableUI extends BasicTableUI {
private MouseInputHandler handler = new MouseInputHandler() {
public void mouseDragged(MouseEvent e) {
if (e.isControlDown()) {
isControlDownInDrag = true;
}
super.mouseDragged(e);
}
public void mousePressed(MouseEvent e) {
isControlDownInDrag = false;
super.mousePressed(e);
}
public void mouseReleased(MouseEvent e) {
isControlDownInDrag = false;
super.mouseReleased(e);
}
};
protected MouseInputListener createMouseInputListener() {
return handler;
}
}
public void changeSelection(int rowIndex, int columnIndex, boolean toggle, boolean extend) {
if (isControlDownInDrag) {
ListSelectionModel rsm = getSelectionModel();
ListSelectionModel csm = getColumnModel().getSelectionModel();
int anchorRow = rsm.getAnchorSelectionIndex();
int anchorCol = csm.getAnchorSelectionIndex();
boolean anchorSelected = isCellSelected(anchorRow, anchorCol);
if (anchorSelected) {
rsm.addSelectionInterval(anchorRow, rowIndex);
csm.addSelectionInterval(anchorCol, columnIndex);
} else {
rsm.removeSelectionInterval(anchorRow, rowIndex);
csm.removeSelectionInterval(anchorCol, columnIndex);
}
if (getAutoscrolls()) {
Rectangle cellRect = getCellRect(rowIndex, columnIndex, false);
if (cellRect != null) {
scrollRectToVisible(cellRect);
}
}
} else {
super.changeSelection(rowIndex, columnIndex, toggle, extend);
}
}
}
Note Curtsey to http://bugs.sun.com