自定义AbstractTableModel无法正确显示数据

Question

I want to extract data from a table in the database based on the columns I specify using an AbstractTableModel. There are 8 columns in the table but want to only show 3 of the 8 columns.

For example:

The database has these columns: ID, First_Name, Last_Name, ...., Phone_Number. If I specify that I want to display First_Name, Last_Name, Phone_Number in the table it shows me ID, First_Name, and Last_Name. I think I should specify the index of the column name from the database to display the correct column but do not know how to implement that in my custom AbstractTableModel class.

public class PhysicianModelController extends AbstractTableModel 
{
    PhysicianBroker pb = PhysicianBroker.getPhysicianBroker();

private String[] columnNames =  {"First Name", "Last Name", "Phone Number"};

private ArrayList<Physician> ph = pb.getAllPhysicians();

@Override
public int getRowCount() {
    return ph.size();
}

@Override
public int getColumnCount() {
    return columnNames.length;
}

@Override
public String getColumnName(int col)
{
    System.out.println(col);
    return columnNames[col];
}   

@Override
public String getValueAt(int rowIndex, int columnIndex) {  
    System.out.println(rowIndex + " : " + columnIndex);
    Physician p = ph.get(rowIndex);
    switch (columnIndex)
    {
        case 0:
            return Integer.toString(p.getEmployeeId());                
        case 1:
            return p.getFirstName();
        case 2:
            return p.getLastName();
        case 3:
            return p.getBirthDate();
        case 4:
            return p.getStartDate();
        case 5:
            return p.getEndDate();
        case 6:
            return p.getAddress();
        case 7:
            return p.getPhoneNumber();
        default:
            return "Incorrect input";                          
    }
}

public void addRow(Physician p) 
{
    ph.add(p);
    int row = ph.size();
    fireTableRowsInserted(row,row);
    fireTableDataChanged();
}

@Override
public Class getColumnClass(int c)
{
    return getValueAt(0,c).getClass();
}

}

I have overridden the getRowCount(), getColumnCount(), getColumnName(), getValueAt(), and getColumnClass() methods with my implementation. Everything works correctly once I supply all the columns from the database table.

Would someone be kind enough to lend me a hand on how to do this?

Thanks

Answer 1

Watch your getValueAt method. You have only three columns . So you should return the value according to that. What was happening that for column 0 you was getting employee id whereas you wanted Firstname..So on...

@Override
public String getValueAt(int rowIndex, int columnIndex) {  
    System.out.println(rowIndex + " : " + columnIndex);
    Physician p = ph.get(rowIndex);
    switch (columnIndex)
    {

        case 0:
            return p.getFirstName();
        case 1:
            return p.getLastName();
        case 2:
            return p.getPhoneNumber();
        default:
            return "Incorrect input";                          
    }
}

UPDATE
Here is a code demo to add a row in JTable. Have a look on it:

import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.table.*;
import java.util.*;
class Person
{
    String name;
    String roll;
    String subject;
    public Person(String name,String roll,String subject)
    {
        this.name = name;
        this.roll = roll;
        this.subject = subject;
    }
    public String getName()
    {
        return name;
    }
    public String getRoll()
    {
        return roll;
    }
    public String getSubject()
    {
        return subject;
    }
    public void setName(String name)
    {
        this.name = name;
    }
    public void setRoll(String roll)
    {
        this.roll = roll;
    }
    public void setSubject(String subject)
    {
        this.subject = subject;
    }
}
class TableRowAdd extends JFrame  
{
    private JTable table;
    private JScrollPane jsPane;
    private MyModel myModel;
    private JPanel dialogPanel;
    private JTextField tf[];
    private JLabel     lbl[];
    private JButton    button;
    JDialog dialog;
    public void prepareAndShowGUI()
    {
        myModel = new MyModel();
        table = new JTable(myModel);
        jsPane = new JScrollPane(table);
        button = new JButton("Add");
        button.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent evt)
            {
                dialog.setVisible(true);
            }
        });
        getContentPane().add(button,BorderLayout.SOUTH);
        getContentPane().add(jsPane);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        prepareDialogPanel();
        pack();
        setVisible(true);

    }
    private void prepareDialogPanel()
    {
        dialogPanel = new JPanel();
        int col = table.getColumnCount();
        dialogPanel.setLayout(new GridLayout(col,2));
        tf = new JTextField[col];
        lbl = new JLabel[col];
        for (int i = 0; i < col; i++)
        {
            lbl[i] = new JLabel(table.getColumnName(i));
            tf[i] = new JTextField(10);
            dialogPanel.add(lbl[i]);
            dialogPanel.add(tf[i]);
        }
        dialog = new JDialog(this,"Enter details",true);
        dialog.getContentPane().add(dialogPanel);
        JButton okButton = new JButton("OK");
        dialog.getContentPane().add(okButton,BorderLayout.SOUTH);
        okButton.addActionListener( new ActionListener()
        {
            public void actionPerformed(ActionEvent evt)
            {
                dialog.dispose();
                myModel.addRow(new Person(tf[0].getText(),tf[1].getText(),tf[2].getText()));
            }
        });
        dialog.pack();
    }
    private class MyModel extends AbstractTableModel 
    {
        String[] columns = {
                            "Roll No.",
                            "Name",
                            "Subject"
                            };
        ArrayList<Person> inData = new ArrayList<Person>()
                            {
                                {
                                    add(new Person("1","Anthony Hopkins","CS01"));
                                    add(new Person("2","James William","CS02"));
                                    add(new Person("3","Mc. Donald","CS03"));
                                }
                            };
        @Override
        public void setValueAt(Object value, int row, int col)
        {
            Person person = inData.get(row);
            switch(col)
            {
                case 0: 
                    person.setRoll((String)value);
                    break;
                case 1:
                    person.setName((String)value);
                    break;
                case 2:
                    person.setSubject((String)value);
                    break;
                default:
                    System.out.println("Invalid col");

            }
            fireTableCellUpdated(row,col);
        }
        @Override
        public Object getValueAt(int row, int col)
        {
            Person person = inData.get(row);
            switch(col)
            {
                case 0: 
                    return person.getRoll();
                case 1:
                    return person.getName();
                case 2:
                    return person.getSubject();
                default:
                    return null;
            }
        }
        @Override
        public int getColumnCount()
        {
            return columns.length;
        }
        @Override 
        public int getRowCount()
        {
            return inData.size();
        }
        @Override
        public String getColumnName(int col)
        {
            return columns[col];
        }
        @Override
        public boolean isCellEditable(int row ,int col)
        {
            return true;
        }
        //This method adds a row to the table
        public void addRow(Person person)
        {
            inData.add(person);
            fireTableRowsInserted(inData.size() - 1 ,inData.size() - 1);
        }
    }
    public static void main(String st[])
    {
        SwingUtilities.invokeLater( new Runnable()
        {
            @Override
            public void run()
            {
                TableRowAdd td = new TableRowAdd();
                td.prepareAndShowGUI();
            }
        });
    }
}