Creating an Editable Table in Java

Abhishek Dubey
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Introduction

In this article we are going to making a table. This table is not a static table; its editable. And in my previous article The Use of JTable in Swing we describe how to create a table and insert data in to table. Today we describe how changes can be made in a table Dynamically. Editable is nothing; it just is a simple table with some flexible options within a table.

In this example we are going to use a java class DefualtCellEditor. With the help of this class we make cells of a table editable.

DefaultCellEditor class API Description

Constructors

DefaultCellEditor(JCheckBox checkBox) : Constructs a DefaultCellEditor object that uses a check box.
DefaultCellEditor(JComboBox comboBox) : Constructs a DefaultCellEditor object that uses a combo box.
DefaultCellEditor(JTextField textField) : Constructs a DefaultCellEditor that uses a text field.

General use methods

void cancelCellEditing() : Forwards the message from the CellEditor to the delegate.
Object getCellEditorValue() : Forwards the message from the CellEditor to the delegate.
int getClickCountToStart() : Returns the number of clicks needed to start editing.
Component getComponent() : Returns a reference to the editor component.
boolean isCellEditable(EventObject anEvent) : Forwards the message from the CellEditor to the delegate.
void setClickCountToStart(int count) : Specifies the number of clicks needed to start editing.
boolean shouldSelectCell(EventObject anEvent) : Forwards the message from the CellEditor to the delegate.
boolean stopCellEditing() : Forwards the message from the CellEditor to the delegate.

Code Explanation

Step 1: Importing necessary packages because we use the following classes of appropriate packages:

import javax.swing.DefaultCellEditor;

import javax.swing.JComboBox;

import javax.swing.JFrame;

import javax.swing.JScrollPane;

import javax.swing.JTable;

import javax.swing.table.AbstractTableModel;

import javax.swing.table.TableModel;

Step 2: Creating a class and main methods with a frame:

public class EditableTable

{

public static void main(String[] a)

{

JFrame frame = new JFrame();

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Step 3: Creating a two dimensional array of object types containing data information and a single dimensional array of title and education String type.

String[] Education = { "PG","Msc", "B-Tech,","Bsc", "12th", "10th" };

String[] columnTitles = { "First Name", "Last Name", "weight", "Qualification", "age(18+)" };

Object[][] dataEntries = {

{ "ABHISHEK", "DUBEY", new Integer(50), "B-tech", new Boolean(false) },

{ "MANISH", "TIWARI", new Integer(80), "PG", new Boolean(true) },

{ "ANURUDDHA ", "PANDEY", new Integer(80), "Msc", new Boolean(true) },

{ "Bindresh", "AGINHOTRI", new Integer(80), "Bsc", new Boolean(true) },

{ "SOURABH", "TRIPATHI", new Integer(80), "PG", new Boolean(true) },

{ "AMIT", "GUPTA", new Integer(70), "Gratuate", new Boolean(false) },

{ "AMIT", "VERMA", new Integer(55), "12TH", new Boolean(true) }, };

Step 4: Creating another component object.

JComboBox comboBox = new JComboBox(Education);

table.getColumnModel().getColumn(3).setCellEditor(new DefaultCellEditor(comboBox));

frame.add(new JScrollPane(table));

frame.setSize(300, 200);

frame.setVisible(true);

Step 5: Creating another a class which contains some helper methods.

class EditableTableModel extends AbstractTableModel

{

String[] columnTitles;

Object[][] dataEntries;

int rowCount;

public EditableTableModel(String[] columnTitles, Object[][] dataEntries)

{

this.columnTitles = columnTitles;

this.dataEntries = dataEntries;

}

public int getRowCount()

{

return dataEntries.length;

}

public int getColumnCount()

{

return columnTitles.length;

}

public Object getValueAt(int row, int column)

{

return dataEntries[row][column];

}

public String getColumnName(int column)

{

return columnTitles[column];

}

public Class getColumnClass(int column)

{

return getValueAt(0, column).getClass();

}

public boolean isCellEditable(int row, int column)

{

return true;

}

public void setValueAt(Object value, int row, int column)

{

dataEntries[row][column] = value;

}

}

Complete code

import javax.swing.DefaultCellEditor;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableModel;
public class EditableTable
{
  public static void main(String[] a)
{
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
String[] columnTitles = { "First Name", "Last Name", "weight", "Qualification", "age(18+)" };
Object[][] dataEntries = {
{ "ABHISHEK", "DUBEY", new Integer(50), "B-tech", new Boolean(false) },
{ "MANISH", "TIWARI", new Integer(80), "PG", new Boolean(true) },
{ "ANURUDDHA ", "PANDEY", new Integer(80), "Msc", new Boolean(true) },
{ "Bindresh", "AGINHOTRI", new Integer(80), "Bsc", new Boolean(true) },
{ "SOURABH", "TRIPATHI", new Integer(80), "PG", new Boolean(true) },
{ "AMIT", "GUPTA", new Integer(70), "Gratuate", new Boolean(false) },
{ "AMIT", "VERMA", new Integer(55), "12TH", new Boolean(true) }, };
TableModel model = new EditableTableModel(columnTitles, dataEntries);
JTable table = new JTable(model);
table.createDefaultColumnsFromModel();
String[] Education = { "PG","Msc", "B-Tech,","Bsc", "12th", "10th" };
JComboBox comboBox = new JComboBox(Education);
table.getColumnModel().getColumn(3).setCellEditor(new DefaultCellEditor(comboBox));
rame.add(new JScrollPane(table));
frame.setSize(300, 200);
frame.setVisible(true);
}
}
   class EditableTableModel extends AbstractTableModel
{
String[] columnTitles;
Object[][] dataEntries;
  int rowCount;
  public EditableTableModel(String[] columnTitles, Object[][] dataEntries)
{
  this.columnTitles = columnTitles;
  this.dataEntries = dataEntries;
}
  public int getRowCount()
{
  return dataEntries.length;
}
  public int getColumnCount()
{
  return columnTitles.length;
}
  public Object getValueAt(int row, int column)
{
  return dataEntries[row][column];
}
  public String getColumnName(int column)
{
  return columnTitles[column];
}
  public Class getColumnClass(int column)
{
  return getValueAt(0, column).getClass();
}
  public boolean isCellEditable(int row, int column)
{
  return true;
}
  public void setValueAt(Object value, int row, int column)
{
dataEntries[row][column] = value;
}
}
}

Output

Initial output of cmd.

Basic output(first look):

The following output shows the modified option:

By using the mouse pointer you can edit the age column:

Resources

Populating and Editing a DataGrid in ASP.NET
How to Create and Use the Editable Grid Screen in LightSwitch Beta 2
Fully editable grid Using The Repeater Control
Data Screens in LightSwitch 2011: Part 3
Editable ListBox in C#