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how to retrieve data from database to table using model view controller(mvc) model in swing [duplicate]

I'm making a GUI Project for database there are two classes which are for GUI's. And connector class is used to connect from user credentials. If credentials are correct than it fetch all data in the from of AbstractTableModel. When program run first GUI has a button in which we click it and it fetch all data in underlying TableModel. But i'm facing two problems. First in GUI2 class, sometimes it open like this.
and sometimes it show like this
I don't know why it's happening. And second problem is when we select any row from table and click on DeleteSelectedRow button it delete the row. This button has a ActionListener in GUI2 class. But what i want is i automatic update the table when row has been deleted. How can i do that?
class for first GUI
public class Gui extends JFrame {
private static Connector conni;
private Connection conn = null;
private JButton bt;
private JPanel panel;
public Gui() {
super("Frame");
panel = new JPanel();
bt = new JButton("Connect to Database 'World'");
panel.add(bt);
bt.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
conn = conni.Connector();
if (conn != null) {
dispose();
new Gui2(conn);
} else {
System.out.println("Return false");
}
}
});
add(panel);
pack();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
}
Connector class
public class Connector {
private static Connection conn = null;
public static Connection Connector() {
String data = "jdbc:mysql://localhost/world";
String user = "root";
String pass = "toot";
try {
conn = DriverManager.getConnection(data, user, pass);
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e.getMessage());
}
if (conn != null) {
System.out.println("Connection Suceess");
return conn;
} else {
return conn;
}
}
}
class for second GUI2
public class Gui2 extends JFrame {
private Statement state = null;
private ResultSet rs = null;
private JButton bt, delete;
private JTextField text;
private JPanel panel;
private GridBagLayout layout;
private GridBagConstraints constraints;
public Gui2(Connection conn) {
layout = new GridBagLayout();
constraints = new GridBagConstraints();
panel = new JPanel();
panel.setLayout(layout);
text = new JTextField(15);
bt = new JButton("Submit Query");
delete = new JButton("Delete Selected Row");
constraints.insets = new Insets(5, 2, 5, 10);
constraints.gridy = 0;// row 0
constraints.gridx = 0;// column 0
// TextField add on JPanel with given constraints
panel.add(text, constraints);
constraints.gridx++;
panel.add(delete, constraints);
constraints.gridx++;
panel.add(bt, constraints);
// North BorderLayout
add(panel, BorderLayout.NORTH);
try {
state = conn.createStatement();
rs = state.executeQuery("select * from city");
} catch (SQLException e) {
JOptionPane.showMessageDialog(null, e.getMessage());
}
JTable table = new JTable();
JScrollPane spane = new JScrollPane(table);
add(spane, BorderLayout.CENTER);
table.setModel(new TableModel(rs));
delete.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
int rowIndex = table.getSelectedRow();
Object columnIndexValue = table.getModel().getValueAt(rowIndex, 0);
String columnName = table.getModel().getColumnName(0);
String query = "delete from world.city" + " where " + columnName + "=" + columnIndexValue;
try {
PreparedStatement pre = conn.prepareStatement(query);
pre.executeUpdate();
JOptionPane.showMessageDialog(null, "Row Deleted Successfully");
} catch (Exception e1) {
JOptionPane.showMessageDialog(null, e1.getMessage());
}
}
});
setSize(817, 538);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
}
Tablemodel Class
public class TableModel extends AbstractTableModel {
private List ColumnHeader;
private List tableData;
private List rowData;
private int totalcolumn;
public TableModel(ResultSet rs) {
try {
ResultSetMetaData meta = rs.getMetaData();
totalcolumn = meta.getColumnCount();
ColumnHeader = new ArrayList(totalcolumn);
tableData = new ArrayList();
for (int i = 1; i <= totalcolumn; i++) {
ColumnHeader.add(meta.getColumnName(i));
}
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e.getMessage());
}
SwingWorker<Boolean, List<Object>> worker = new SwingWorker<Boolean, List<Object>>() {
#Override
protected Boolean doInBackground() throws Exception {
while (rs.next()) {
rowData = new ArrayList(totalcolumn);
for (int i = 1; i <= totalcolumn; i++) {
rowData.add(rs.getObject(i));
}
publish(rowData);
}
return true;
}
#Override
protected void process(List chunks) {
tableData.add(chunks);
}
#Override
protected void done() {
try {
Boolean status = get();
JOptionPane.showMessageDialog(null, "Task is DONE");
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}
};
worker.execute();
}// constructor end
#Override
public int getColumnCount() {
return ColumnHeader.size();
}
public String getColumnName(int columnIndex) {
return (String) ColumnHeader.get(columnIndex);
}
#Override
public int getRowCount() {
return tableData.size();
}
#Override
public Object getValueAt(int rowIndex, int columnIndex) {
List rowData2 = (List) tableData.get(rowIndex);
return rowData2.get(columnIndex);
}
}

Because database access is inherently asynchronous, you'll surely want to retrieve rows in the background to avoid blocking the event dispatch thread; SwingWorker makes this relatively easy. Fetch rows in your implementation of doInBackground(), publish() interim results, and add them to the table model in your implementation of process(). A complete example that outlines the attendant benefits is shown here. The example loops through a file, but you can substitute your ResultSet operations.
while (rs.next()) {
//collect row data
publish(rowData);
}
Defer tableData.add() to your implementation of process().
Focusing on the interaction between the custom TableModel and its contained SwingWorker, the following complete example creates a test database having N rows and displays a JTable showing the results of a query of that table. In particular,
JDBCModel extends AbstractTableModel. For simplicity, the model's data is stored in a List<Row>, and ResultSetMetaData is used for the column names. As a more abstract alternative, see Apache Commons DbUtils, which uses Class Literals as Runtime-Type Tokens and ResultSetMetaData to safely create instances of row data.
JDBCModel delegates row retrieval to a private JDBCWorker; it invokes publish() on each row retrieved from the ResultSet; because process() runs on the EDT, the worker can optimize the number of table model events that it fires on behalf of the parent model using fireTableRowsInserted().
Similarly, your implementation of delete() should reside in JDBCModel, not the GUI; it should fireTableRowsDeleted() after the row is successfully deleted from the database and removed from data.
Add Thread.sleep() to the worker's background loop to see the effect of artificially increasing latency.
Use setProgress() and a PropertyChangeListener, shown here, to display progress; a JOptionPane when done() may be superfluous.
Override getPreferredScrollableViewportSize() to customize the size of the table's enclosing JScrollPane.
Avoid class names, e.g. TableModel, that collide with common API names.
A variation that implements live filtering in the view is examined here.
import java.awt.Dimension;
import java.awt.EventQueue;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingWorker;
import javax.swing.table.AbstractTableModel;
/**
* #see https://stackoverflow.com/a/34742409/230513
* #see https://stackoverflow.com/a/24762078/230513
*/
public class WorkerTest {
private static final int N = 1_000;
private static final String URL = "jdbc:h2:mem:test";
private static final Random r = new Random();
private void display() {
JFrame f = new JFrame("WorkerTest");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
createTestDatabase(N);
JDBCModel model = new JDBCModel(getConnection(), "select * from city");
f.add(new JScrollPane(new JTable(model) {
#Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(320, 240);
}
}));
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private static class Row {
int ID;
String name;
}
private static class JDBCModel extends AbstractTableModel {
private final List<Row> data = new ArrayList<>();
private ResultSet rs = null;
private ResultSetMetaData meta;
public JDBCModel(Connection conn, String query) {
try {
Statement s = conn.createStatement();
rs = s.executeQuery(query);
meta = rs.getMetaData();
JDBCWorker worker = new JDBCWorker();
worker.execute();
} catch (SQLException e) {
e.printStackTrace(System.err);
}
}
#Override
public int getRowCount() {
return data.size();
}
#Override
public int getColumnCount() {
try {
return meta.getColumnCount();
} catch (SQLException e) {
e.printStackTrace(System.err);
}
return 0;
}
#Override
public Object getValueAt(int rowIndex, int colIndex) {
Row row = data.get(rowIndex);
switch (colIndex) {
case 0:
return row.ID;
case 1:
return row.name;
}
return null;
}
#Override
public String getColumnName(int colIndex) {
try {
return meta.getColumnName(colIndex + 1);
} catch (SQLException e) {
e.printStackTrace(System.err);
}
return null;
}
private class JDBCWorker extends SwingWorker<List<Row>, Row> {
#Override
protected List<Row> doInBackground() {
try {
while (rs.next()) {
Row r = new Row();
r.ID = rs.getInt(1);
r.name = rs.getString(2);
publish(r);
}
} catch (SQLException e) {
e.printStackTrace(System.err);
}
return data;
}
#Override
protected void process(List<Row> chunks) {
int n = getRowCount();
for (Row row : chunks) {
data.add(row);
}
fireTableRowsInserted(n, n + chunks.size());
}
}
}
private static void createTestDatabase(int n) {
Connection conn = getConnection();
try {
Statement st = conn.createStatement();
st.execute("create table city(id integer, name varchar2)");
PreparedStatement ps = conn.prepareStatement(
"insert into city values (?, ?)");
for (int i = 0; i < n; i++) {
ps.setInt(1, i);
ps.setString(2, (char) ('A' + r.nextInt(26))
+ String.valueOf(r.nextInt(1_000_000)));
ps.execute();
}
} catch (SQLException ex) {
ex.printStackTrace(System.err);
}
}
private static Connection getConnection() {
try {
return DriverManager.getConnection(URL, "", "");
} catch (SQLException e) {
e.printStackTrace(System.err);
}
return null;
}
public static void main(String[] args) {
EventQueue.invokeLater(new WorkerTest()::display);
}
}

Display database table with swing (Columns names do not show up) [duplicate]

I'm making a GUI Project for database there are two classes which are for GUI's. And connector class is used to connect from user credentials. If credentials are correct than it fetch all data in the from of AbstractTableModel. When program run first GUI has a button in which we click it and it fetch all data in underlying TableModel. But i'm facing two problems. First in GUI2 class, sometimes it open like this.
and sometimes it show like this
I don't know why it's happening. And second problem is when we select any row from table and click on DeleteSelectedRow button it delete the row. This button has a ActionListener in GUI2 class. But what i want is i automatic update the table when row has been deleted. How can i do that?
class for first GUI
public class Gui extends JFrame {
private static Connector conni;
private Connection conn = null;
private JButton bt;
private JPanel panel;
public Gui() {
super("Frame");
panel = new JPanel();
bt = new JButton("Connect to Database 'World'");
panel.add(bt);
bt.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
conn = conni.Connector();
if (conn != null) {
dispose();
new Gui2(conn);
} else {
System.out.println("Return false");
}
}
});
add(panel);
pack();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
}
Connector class
public class Connector {
private static Connection conn = null;
public static Connection Connector() {
String data = "jdbc:mysql://localhost/world";
String user = "root";
String pass = "toot";
try {
conn = DriverManager.getConnection(data, user, pass);
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e.getMessage());
}
if (conn != null) {
System.out.println("Connection Suceess");
return conn;
} else {
return conn;
}
}
}
class for second GUI2
public class Gui2 extends JFrame {
private Statement state = null;
private ResultSet rs = null;
private JButton bt, delete;
private JTextField text;
private JPanel panel;
private GridBagLayout layout;
private GridBagConstraints constraints;
public Gui2(Connection conn) {
layout = new GridBagLayout();
constraints = new GridBagConstraints();
panel = new JPanel();
panel.setLayout(layout);
text = new JTextField(15);
bt = new JButton("Submit Query");
delete = new JButton("Delete Selected Row");
constraints.insets = new Insets(5, 2, 5, 10);
constraints.gridy = 0;// row 0
constraints.gridx = 0;// column 0
// TextField add on JPanel with given constraints
panel.add(text, constraints);
constraints.gridx++;
panel.add(delete, constraints);
constraints.gridx++;
panel.add(bt, constraints);
// North BorderLayout
add(panel, BorderLayout.NORTH);
try {
state = conn.createStatement();
rs = state.executeQuery("select * from city");
} catch (SQLException e) {
JOptionPane.showMessageDialog(null, e.getMessage());
}
JTable table = new JTable();
JScrollPane spane = new JScrollPane(table);
add(spane, BorderLayout.CENTER);
table.setModel(new TableModel(rs));
delete.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
int rowIndex = table.getSelectedRow();
Object columnIndexValue = table.getModel().getValueAt(rowIndex, 0);
String columnName = table.getModel().getColumnName(0);
String query = "delete from world.city" + " where " + columnName + "=" + columnIndexValue;
try {
PreparedStatement pre = conn.prepareStatement(query);
pre.executeUpdate();
JOptionPane.showMessageDialog(null, "Row Deleted Successfully");
} catch (Exception e1) {
JOptionPane.showMessageDialog(null, e1.getMessage());
}
}
});
setSize(817, 538);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
}
Tablemodel Class
public class TableModel extends AbstractTableModel {
private List ColumnHeader;
private List tableData;
private List rowData;
private int totalcolumn;
public TableModel(ResultSet rs) {
try {
ResultSetMetaData meta = rs.getMetaData();
totalcolumn = meta.getColumnCount();
ColumnHeader = new ArrayList(totalcolumn);
tableData = new ArrayList();
for (int i = 1; i <= totalcolumn; i++) {
ColumnHeader.add(meta.getColumnName(i));
}
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e.getMessage());
}
SwingWorker<Boolean, List<Object>> worker = new SwingWorker<Boolean, List<Object>>() {
#Override
protected Boolean doInBackground() throws Exception {
while (rs.next()) {
rowData = new ArrayList(totalcolumn);
for (int i = 1; i <= totalcolumn; i++) {
rowData.add(rs.getObject(i));
}
publish(rowData);
}
return true;
}
#Override
protected void process(List chunks) {
tableData.add(chunks);
}
#Override
protected void done() {
try {
Boolean status = get();
JOptionPane.showMessageDialog(null, "Task is DONE");
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}
};
worker.execute();
}// constructor end
#Override
public int getColumnCount() {
return ColumnHeader.size();
}
public String getColumnName(int columnIndex) {
return (String) ColumnHeader.get(columnIndex);
}
#Override
public int getRowCount() {
return tableData.size();
}
#Override
public Object getValueAt(int rowIndex, int columnIndex) {
List rowData2 = (List) tableData.get(rowIndex);
return rowData2.get(columnIndex);
}
}

Because database access is inherently asynchronous, you'll surely want to retrieve rows in the background to avoid blocking the event dispatch thread; SwingWorker makes this relatively easy. Fetch rows in your implementation of doInBackground(), publish() interim results, and add them to the table model in your implementation of process(). A complete example that outlines the attendant benefits is shown here. The example loops through a file, but you can substitute your ResultSet operations.
while (rs.next()) {
//collect row data
publish(rowData);
}
Defer tableData.add() to your implementation of process().
Focusing on the interaction between the custom TableModel and its contained SwingWorker, the following complete example creates a test database having N rows and displays a JTable showing the results of a query of that table. In particular,
JDBCModel extends AbstractTableModel. For simplicity, the model's data is stored in a List<Row>, and ResultSetMetaData is used for the column names. As a more abstract alternative, see Apache Commons DbUtils, which uses Class Literals as Runtime-Type Tokens and ResultSetMetaData to safely create instances of row data.
JDBCModel delegates row retrieval to a private JDBCWorker; it invokes publish() on each row retrieved from the ResultSet; because process() runs on the EDT, the worker can optimize the number of table model events that it fires on behalf of the parent model using fireTableRowsInserted().
Similarly, your implementation of delete() should reside in JDBCModel, not the GUI; it should fireTableRowsDeleted() after the row is successfully deleted from the database and removed from data.
Add Thread.sleep() to the worker's background loop to see the effect of artificially increasing latency.
Use setProgress() and a PropertyChangeListener, shown here, to display progress; a JOptionPane when done() may be superfluous.
Override getPreferredScrollableViewportSize() to customize the size of the table's enclosing JScrollPane.
Avoid class names, e.g. TableModel, that collide with common API names.
A variation that implements live filtering in the view is examined here.
import java.awt.Dimension;
import java.awt.EventQueue;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingWorker;
import javax.swing.table.AbstractTableModel;
/**
* #see https://stackoverflow.com/a/34742409/230513
* #see https://stackoverflow.com/a/24762078/230513
*/
public class WorkerTest {
private static final int N = 1_000;
private static final String URL = "jdbc:h2:mem:test";
private static final Random r = new Random();
private void display() {
JFrame f = new JFrame("WorkerTest");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
createTestDatabase(N);
JDBCModel model = new JDBCModel(getConnection(), "select * from city");
f.add(new JScrollPane(new JTable(model) {
#Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(320, 240);
}
}));
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private static class Row {
int ID;
String name;
}
private static class JDBCModel extends AbstractTableModel {
private final List<Row> data = new ArrayList<>();
private ResultSet rs = null;
private ResultSetMetaData meta;
public JDBCModel(Connection conn, String query) {
try {
Statement s = conn.createStatement();
rs = s.executeQuery(query);
meta = rs.getMetaData();
JDBCWorker worker = new JDBCWorker();
worker.execute();
} catch (SQLException e) {
e.printStackTrace(System.err);
}
}
#Override
public int getRowCount() {
return data.size();
}
#Override
public int getColumnCount() {
try {
return meta.getColumnCount();
} catch (SQLException e) {
e.printStackTrace(System.err);
}
return 0;
}
#Override
public Object getValueAt(int rowIndex, int colIndex) {
Row row = data.get(rowIndex);
switch (colIndex) {
case 0:
return row.ID;
case 1:
return row.name;
}
return null;
}
#Override
public String getColumnName(int colIndex) {
try {
return meta.getColumnName(colIndex + 1);
} catch (SQLException e) {
e.printStackTrace(System.err);
}
return null;
}
private class JDBCWorker extends SwingWorker<List<Row>, Row> {
#Override
protected List<Row> doInBackground() {
try {
while (rs.next()) {
Row r = new Row();
r.ID = rs.getInt(1);
r.name = rs.getString(2);
publish(r);
}
} catch (SQLException e) {
e.printStackTrace(System.err);
}
return data;
}
#Override
protected void process(List<Row> chunks) {
int n = getRowCount();
for (Row row : chunks) {
data.add(row);
}
fireTableRowsInserted(n, n + chunks.size());
}
}
}
private static void createTestDatabase(int n) {
Connection conn = getConnection();
try {
Statement st = conn.createStatement();
st.execute("create table city(id integer, name varchar2)");
PreparedStatement ps = conn.prepareStatement(
"insert into city values (?, ?)");
for (int i = 0; i < n; i++) {
ps.setInt(1, i);
ps.setString(2, (char) ('A' + r.nextInt(26))
+ String.valueOf(r.nextInt(1_000_000)));
ps.execute();
}
} catch (SQLException ex) {
ex.printStackTrace(System.err);
}
}
private static Connection getConnection() {
try {
return DriverManager.getConnection(URL, "", "");
} catch (SQLException e) {
e.printStackTrace(System.err);
}
return null;
}
public static void main(String[] args) {
EventQueue.invokeLater(new WorkerTest()::display);
}
}

How do i get the id of the cell click using JTable?

I am using a JTable to display data from my database. What I want to happen is that when a row is clicked it opens another window.
My Code
Connection to the database
public class JFrametest extends javax.swing.JFrame {
private static Connection connection;
private static Statement stmt;
static {
// standard code to open a connection and statement to Java Derby database
try {
NetworkServerControl server = new NetworkServerControl();
server.start(null);
// Load JDBC driver
Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
//Establish a connection
String sourceURL = "jdbc:derby://localhost:1527/"
+ new File("EmailsDB").getAbsolutePath() + ";";
connection = DriverManager.getConnection(sourceURL, "student", "student");
stmt = connection.createStatement();
} // The following exceptions must be caught
catch (ClassNotFoundException cnfe) {
out.println(cnfe);
} catch (SQLException sqle) {
out.println(sqle);
} catch (Exception e) {
System.out.println(e);
}
}
Displaying Data from the database
try {
String query = "select * from messages";
PreparedStatement pst = connection.prepareStatement(query);
ResultSet rs = pst.executeQuery();
table.setModel(DbUtils.resultSetToTableModel(rs));
}catch (Exception e) {
e.printStackTrace();
}
As anyone got any ideas on what i can do? is this possible?

You could use a mouseClicked Action Listener to do this.

You can use MouseListener for that, here is simple example:
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
public class TestFrame extends JFrame {
public static void main(String... s) {
new TestFrame();
}
private JTable t;
public TestFrame() {
init();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
setLocationRelativeTo(null);
setVisible(true);
}
private void init() {
DefaultTableModel model = new DefaultTableModel(0,2);
for(int i=0;i<10;i++){
model.addRow(new Object[]{i,"other info "+i});
}
model.setColumnIdentifiers(new Object[]{"id","info"});
t = new JTable(model);
t.addMouseListener(getListener());
add(new JScrollPane(t));
}
protected void showDialog(int rowAtPoint) {
Object valueAt = t.getValueAt(rowAtPoint, 0);
// other operations
JDialog d = new JDialog();
d.setTitle("id="+valueAt);
d.setModal(true);
d.setAlwaysOnTop(true);
d.setLocationRelativeTo(null);
d.pack();
d.setVisible(true);
}
private MouseListener getListener() {
return new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
super.mouseClicked(e);
if(e.getClickCount() >= 1){
int rowAtPoint = t.rowAtPoint(e.getPoint());
if(rowAtPoint != -1)
showDialog(rowAtPoint);
}
}
};
}
}

getSelectedRow() returns -1 after loading new data to existing JTable

I'm writing a simple MySQL editor. My problem is that after I select from the combobox a new table from the database and load it and then select a row and try to delete it, getSelectedRow() returns -1 and generates an exception, but that doesn't happen when I delete a row from the table that is loaded at the start of my program.
Here's the crucial code parts from 2 files (in the same code quote):
package omnisql;
import java.sql.*;
import java.util.*;
public class getData
{
static Connect c = new Connect();
static GUI g = new GUI();
static ResultSet result;
public static Vector<Vector<String>> data = new Vector<Vector<String>>();
public static String table="pracownicy";
public static Vector <String> d;
public static List <String> id;
void getData() throws SQLException
{
result=c.stmt.executeQuery("select * from "+table);
id = new ArrayList<String>();
while(result.next())
{
d=new Vector<String>();
id.add(result.getString("id"));
d.add(result.getString("id"));
d.add(result.getString("Nazwisko"));
d.add(result.getString("Imię"));
d.add(result.getString("Płeć"));
d.add(result.getString("Ulica"));
d.add(result.getString("Miejscowość"));
d.add(result.getString("Kod_pocztowy"));
d.add(result.getString("Województwo"));
d.add(result.getString("Telefon"));
data.add(d);
}
}
}
package omnisql;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.*;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.swing.*;
import javax.swing.table.*;
import java.util.*;
import javax.swing.event.*;
public class GUI extends JFrame implements ActionListener, TableModelListener
{
static Connect c = new Connect();
static getData gd = new getData();
JPanel panel = new JPanel(new FlowLayout(FlowLayout.LEFT,10,5));
JPanel panel1 = new JPanel(new FlowLayout(FlowLayout.LEFT,10,5));
JPanel panel2 = new JPanel(new FlowLayout(FlowLayout.CENTER,10,5));
JPanel panel3 = new JPanel(new FlowLayout(FlowLayout.LEFT,10,5));
JLabel typbazy = new JLabel("Typ bazy: ");
JLabel wybtab = new JLabel("Wybierz tabelę: ");
JRadioButton postgre = new JRadioButton("PostgreSQL");
JRadioButton mysql = new JRadioButton("MySQL");
JRadioButton sqlite = new JRadioButton("SQLite");
ButtonGroup grupa = new ButtonGroup();
public static JComboBox tabela = new JComboBox();
JButton addrec = new JButton("Dodaj rekord");
JButton delrec = new JButton("Usuń rekord");
JButton reftab = new JButton("Odśwież tabelę");
JTable table;
public static DefaultTableModel model;
TableColumn column;
Vector<String> headers = new Vector<String>();
JScrollPane scroll;
static int rownumber,addrow,delrow,updaterow;
PreparedStatement pst;
String value="";
public static int height,i,firstrow=0, klick=1;
public GUI()
{
panel.add(typbazy);
grupa.add(postgre);
panel.add(postgre);
postgre.addActionListener(this);
grupa.add(mysql);
panel.add(mysql);
mysql.setSelected(rootPaneCheckingEnabled);
mysql.addActionListener(this);
grupa.add(sqlite);
panel.add(sqlite);
sqlite.addActionListener(this);
panel1.add(wybtab);
panel1.add(tabela);
tabela.setPreferredSize(new Dimension(120,20));
tabela.setBackground(Color.white);
tabela.removeAllItems();
tabela.addItem(" ");
tabela.addItem("Pracownicy");
tabela.addItem("Pracownicy 2");
tabela.setSelectedIndex(0);
tabela.addActionListener(this);
headers.add("ID");
headers.add("Nazwisko");
headers.add("Imię");
headers.add("Płeć");
headers.add("Ulica");
headers.add("Miejscowość");
headers.add("Kod_pocztowy");
headers.add("Województwo");
headers.add("Telefon");
model = new DefaultTableModel(gd.data, headers);
table = new JTable(model);
table.setRowSelectionAllowed(true);
table.getModel().addTableModelListener(this);
table.setPreferredScrollableViewportSize(new Dimension(740,159));
column = table.getColumnModel().getColumn(0);
column.setPreferredWidth(20);
column = table.getColumnModel().getColumn(1);
column.setPreferredWidth(100);
column = table.getColumnModel().getColumn(2);
column.setPreferredWidth(70);
column = table.getColumnModel().getColumn(3);
column.setPreferredWidth(70);
column = table.getColumnModel().getColumn(4);
column.setPreferredWidth(100);
column = table.getColumnModel().getColumn(5);
column.setPreferredWidth(100);
column = table.getColumnModel().getColumn(6);
column.setPreferredWidth(100);
column = table.getColumnModel().getColumn(7);
column.setPreferredWidth(100);
column = table.getColumnModel().getColumn(8);
column.setPreferredWidth(80);
scroll = new JScrollPane(table);
panel2.add(scroll);
panel3.add(addrec);
addrec.addActionListener(this);
panel3.add(delrec);
delrec.addActionListener(this);
panel3.add(reftab);
reftab.addActionListener(this);
getContentPane().setLayout(new BoxLayout(getContentPane(), BoxLayout.Y_AXIS));
getContentPane().add(panel);
getContentPane().add(panel1);
getContentPane().add(panel2);
getContentPane().add(panel3);
}
void initGUI()
{
setSize(800,340);
setTitle("OmniSQL 1.0");
setResizable(false);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void tableChanged(TableModelEvent e)
{
rownumber = table.getSelectedRow();
if (rownumber==-1) rownumber=0;
updaterow = Integer.parseInt(gd.id.get(rownumber));
switch (e.getType())
{
case TableModelEvent.UPDATE:
table.getRowCount();
value=table.getValueAt(table.getSelectedRow(),table.getSelectedColumn()).toString();
try
{
pst = c.con.prepareStatement("UPDATE "+gd.table+" SET "+table.getColumnName(table.getSelectedColumn())+" = '"+value+"' where id = "+updaterow+";");
pst.executeUpdate();
}
catch (SQLException err)
{
}
break;
}
}
public void actionPerformed(ActionEvent e)
{
/*if (e.getActionCommand().equals("MySQL"))
{
try
{
c.con.close();
c.connect("jdbc:mysql://localhost:3306/omnisql","root","sqlek","com.mysql.jdbc.Driver");
}
catch (ClassNotFoundException er)
{
}
catch(SQLException err)
{
}
}*/
if (tabela.getSelectedItem()=="Pracownicy")
{
gd.table="pracownicy";
try
{
model.setRowCount(0);
table.removeAll();
gd.getData();
}
catch (SQLException er)
{
}
}
if (tabela.getSelectedItem()=="Pracownicy 2")
{
gd.table="pracownicy2";
try
{
model.setRowCount(0);
gd.getData();
table.revalidate();
}
catch (SQLException er)
{
}
}
/*if(postgre.isSelected())
{
tabela.removeAllItems();
tabela.addItem("Adresy");
tabela.addItem("Adresy 2");
tabela.setSelectedIndex(0);
}
*/
/*if(mysql.isSelected())
{
tabela.removeAllItems();
tabela.addItem(" ");
tabela.addItem("Pracownicy");
tabela.addItem("Pracownicy 2");
}*/
/*
if(sqlite.isSelected())
{
tabela.removeAllItems();
tabela.addItem("Zakłady");
tabela.addItem("Zakłady 2");
tabela.setSelectedIndex(0);
}*/
if (e.getActionCommand().equals("Dodaj rekord"))
{
model.setRowCount(gd.id.size());
rownumber = model.getRowCount()-1;
if(rownumber==-1 && gd.id.size()==0)
{
rownumber=0;
gd.id.add(0, "1");
addrow=Integer.parseInt(gd.id.get(rownumber));
}
else
{
addrow=Integer.parseInt(gd.id.get(rownumber));
addrow++;
}
try
{
pst = c.con.prepareStatement("INSERT INTO "+gd.table+" (id) VALUES("+addrow+")");
pst.executeUpdate();
model.setRowCount(0);
gd.getData();
height = (int)table.getPreferredSize().getHeight();
table.scrollRectToVisible(new Rectangle(0,height,10,10));
}
catch (SQLException exc)
{
}
}
rownumber=table.getSelectedRow();
if (e.getActionCommand().equals("Usuń rekord"))
{
try
{
model.setRowCount(gd.id.size());
System.out.println(rownumber);
delrow = Integer.parseInt(gd.id.get(rownumber));
pst = c.con.prepareStatement("DELETE from "+gd.table+" where id="+delrow);
pst.executeUpdate();
model.setRowCount(0);
gd.getData();
}
catch (SQLException exc)
{
}
}
if (e.getActionCommand().equals("Odśwież tabelę"))
{
try
{
model.setRowCount(0);
gd.getData();
}
catch (SQLException exc)
{
}
}
}
}
I will be really grateful for any help with this problem.

If getSelectedRow() returns -1 that means that nothing is selected.

JTable getSelectedRow does not return the selected row index

I try to get data in the row that is selected but getSelectedRow() doesn't work. Actually, I used that method in the other class, but it works in there. When I try to print the row index; the prompt shows -1; as not selected.
I tried most of solutions that are on the internet but they didn't solve my solutions.
public Canteen() {
try {
jbInit();
} catch (Exception e) {
e.printStackTrace();
}
}
private void jbInit() throws Exception {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.getContentPane().setLayout( null );
this.setSize( new Dimension(400, 300) );
this.setTitle( "CANTEEN" );
jScrollPane1.setBounds(new Rectangle(0, 0, 230, 235));
jButton1.setText("REFRESH");
jButton1.setBounds(new Rectangle(0, 235, 100, 20));
jButton1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
jButton1_actionPerformed(e);
}
});
jButton2.setText("CLOSE");
jButton2.setBounds(new Rectangle(120, 235, 110, 20));
jButton2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
jButton2_actionPerformed(e);
}
});
jScrollPane1.getViewport().add(jTable1, null);
this.getContentPane().add(jButton2, null);
this.getContentPane().add(jButton1, null);
this.getContentPane().add(jScrollPane1, null);
jTable1 = new JTable (model);
String header [] = {"CUSTOMER", "PRODUCT", "QUANTITY","ORDER NO"};
for (int i = 0; i < 4; i++){
model.addColumn(header[i]);
}
//refresh every 1 minute
Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask(){
public void run(){
model.setRowCount(0);
try {
Class.forName(driverName);
conn = DriverManager.getConnection(url,username, password);
statement = conn.createStatement();
ResultSet rs = statement.executeQuery("SELECT USER_NAME, QUANTITY, PRD_NAME, ORDER_NUMBER FROM ORDERS ORDER BY ORDER_NUMBER DESC");
int count = rs.getRow();
String user [] = new String [count];
int i = 0;
while (rs.next()){
String name = rs.getString(1);
String prdName = rs.getString(3);
int number = rs.getInt(2);
int orderNumber = rs.getInt(4);
model.insertRow(i,new Object []{name,prdName,number, orderNumber});
}
conn.close();
}
catch (ClassNotFoundException s) {
System.out.println("Couldn't find the database driver");
System.out.println(s);
}
catch (SQLException s) {
System.out.println("Couldn't connect to the database\n" +s);
}
}
},0, 60000);
}
private void jButton1_actionPerformed(ActionEvent e) {
//set from row 0 for refresh
model.setRowCount(0);
try {
Class.forName(driverName);
conn = DriverManager.getConnection(url,username, password);
statement = conn.createStatement();
ResultSet rs = statement.executeQuery("SELECT USER_NAME, QUANTITY, PRD_NAME FROM ORDERS ORDER BY ORDER_NUMBER DESC");
int count = rs.getRow();
String user [] = new String [count];
int i = 0;
while (rs.next()){
String name = rs.getString(1);
String prdName = rs.getString(3);
int number = rs.getInt(2);
model.insertRow(i,new Object []{name,prdName,number});
}
conn.close();
}
catch (ClassNotFoundException s) {
System.out.println("Couldn't find the database driver");
System.out.println(s);
}
catch (SQLException s) {
System.out.println("Couldn't connect to the database\n" +s);
}
}
private void jButton2_actionPerformed(ActionEvent e) {
System.out.println(jTable1.getSelectedRow());
}
}

Look to your code
private void jbInit() throws Exception {
...
jScrollPane1.getViewport().add(jTable1, null);
this.getContentPane().add(jButton2, null);
this.getContentPane().add(jButton1, null);
this.getContentPane().add(jScrollPane1, null);
jTable1 = new JTable (model);
...
You add jTable1 to the JScrollPane at first and only then you create jTable1. It's incorrect way. jTable1 variable doen't linked now with table you place at the form. I think it's cause of your problem.
Move creation of the jTable1 before adding in into JScrollPane.
...
jTable1 = new JTable (model);
jScrollPane1.getViewport().add(jTable1, null);
this.getContentPane().add(jButton2, null);
this.getContentPane().add(jButton1, null);
this.getContentPane().add(jScrollPane1, null);
...

As your other example shows, getSelectedRow() does work, so you're going to have to debug your code. Comparison with the sscce below may suggest way forward. Both the ActionListener and the ListSelectionListener show the selected row.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.table.DefaultTableModel;
/**
* #see http://stackoverflow.com/q/12301923/230513
*/
public class TableSelection extends JPanel {
private static final String SHOW = "Show";
private DefaultTableModel model = new DefaultTableModel();
private JTable table = new JTable(model);
private JButton button = new JButton(new AbstractAction(SHOW) {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println(table.getSelectedRow());
}
});
public TableSelection() {
model.addColumn("Column");
for (int i = 0; i < 16; i++) {
model.addRow(new Object[]{i});
}
table.setPreferredScrollableViewportSize(new Dimension(160, 100));
table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
table.getSelectionModel().addListSelectionListener(
new ListSelectionListener() {
#Override
public void valueChanged(ListSelectionEvent e) {
if (!e.getValueIsAdjusting()) {
button.setText(SHOW + " " + table.getSelectedRow());
}
}
});
this.add(new JScrollPane(table));
table.setRowSelectionInterval(3, 3);
}
private void display() {
JFrame f = new JFrame("TableSelection");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(this, BorderLayout.CENTER);
f.add(button, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new TableSelection().display();
}
});
}
}