regarding JTable

[ravic johnson]

how to Populate a JTable with MySQL Data after clicking JButton

datails:
data is present in mysql database in tabular form and i want to fetch this data from the database in the form of JTable after clicking JButton
:
please help

[Campbell Ritchie]

You get a ResultSet which has rows, each row with several columns in. You can get the details from the ResultSetMetaData object associated with the ResultSet, eg how many rows, name of column, etc.
You can get the contents of the ResultSet with its next() and getXXX() methods, put them into a List, or an Object[][], and populate the JTable.
Or you can extend DefaultTableModel.
Go through the Java Tutorials and see whether that helps.

And welcome to JavaRanch

[ravic johnson]

i am new to java
i am preparing a project called supply chain system
i took help on it through tutorials on the internet
but i could not exactly understand what you have written
can you please explain it with the help of example

[Rob Spoor]

// assumptions: tableModel is an instance of DefaultTableModel
// rs is your JDBC resultset
 
// remove all rows and columns
tableModel.setRowCount(0);
tableModel.setColumnCount(0);
ResultSetMetaData meta = rs.getMetaData();
int columns = meta.getColumnCount();
// JDBC is one based
for (int i = 1; i <= columns)
{
    tableModel.addColumn(meta.getColumnName(i);
}
while (rs.next())
{
    Object[] row = new Object[columns];
    for (int i = 1; i <= columns; i++)
    {
        row[i - 1] = rs.getObject(i); // 1
    }
    tableModel.addRow(row);
}

1) You could also use other methods, like getString for only string representations. Ideally you should use meta.getColumnType(i) for that. For instance, you can have the following mapping:

Types.CHAR -> java.lang.String
Types.DATE -> java.util.Date
Types.SMALLINT -> java.lang.Short
Types.FLOAT -> java.lang.Float

Check the rest of java.sql.Types for what it could return, and be creative in the mapping.

[ravic johnson]

i have tried it but it is not resulting that i wants
here is the coding of java file which is for opening contents present in mysql database in the form of JTable after clicking JButton
/*

   
import java.sql.*;
import javax.swing.*;
import java.awt.*;
import java.util.*;
import javax.swing.table.*;
 
public class Student{
public static void main(String[] args) {
        Connection con = null;
    String url = "jdbc:mysql://localhost:3306/";
    String db = "ravic";
    String driver = "com.mysql.jdbc.Driver";
    String user = "root";
    String pass = "REMOVED";
    try{
      Class.forName(driver).newInstance();
      con = DriverManager.getConnection(url+db, user, pass);
      try{
        Statement st = con.createStatement();
       ResultSet result = st.executeQuery("SELECT * FROM student1");
DefaultTableModel tableModel;
 
tableModel = new DefaultTableModel();
 
 
JTable table = new JTable(tableModel);
tableModel.setRowCount(0);
tableModel.setColumnCount(0);
ResultSetMetaData md = result.getMetaData();
int columnCount = md.getColumnCount();
 
 Vector columns = new Vector(columnCount);
 
//store column names
for(int i=1; i<=columnCount; i++)
{
tableModel.addColumn(md.getColumnName(i));
//columns.add(md.getColumnName(i));
}
Vector data = new Vector();
Vector row;
 
//store row data
while(result.next())
{
row = new Vector(columnCount);
 //Object[] row = new Object[columns];
for(int i=1; i<=columnCount; i++)
{//row[i - 1] = result.getObject(i);
row.add(result.getString(i));
}
tableModel.addRow(row);
//data.add(row);
}
 
  JFrame frame = new JFrame("Creating JTable Component Example!");
    JPanel panel = new JPanel();
    
    panel.add(new JScrollPane(table),BorderLayout.CENTER);
 panel.setForeground(java.awt.Color.lightGray);
 
 
        panel.setBackground(new java.awt.Color (0, 0, 64));
    
    frame.add(panel);
    frame.setSize(300,200);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        con.close();
      }
      catch (SQLException s){
        System.out.println("SQL code does not execute.");
      }    
    }
    catch (Exception e){
      e.printStackTrace();
    }
  }
}

*/
please help

[Edit]Sorry, but even though it is a private URL I think it's still wiser to remove the password. Rob[/Edit]
[ October 26, 2008: Message edited by: Rob Prime ]

[pete stein]

Originally posted by ravic johnson:
i have tried it but it is not resulting that i wants

You will probably get better help if you go into greater detail here. What is this code doing that is wrong? What is it not doing that it should be doing? etc...

[Rob Spoor]

Originally posted by ravic johnson:
JPanel panel = new JPanel();
panel.add(new JScrollPane(table),BorderLayout.CENTER);
panel.setForeground(java.awt.Color.lightGray);

This is probably not the main problem, but it is still a problem.

JPanel has a FlowLayout by default, so your code will not put in the center of your panel and resize it when your user interface resizes. You need to explicitly give the JPanel a new BorderLayout() for that to work.

[ravic johnson]

according to your advice i went into greater details that is trying to understand the defaulttablemodel concept
i worked on the coding part
made some changes in the coding part
but again i could not to achieve what i want
i am putting that coding part here
please help

    
import java.sql.*;
import javax.swing.*;
import java.awt.*;
import java.util.*;
import javax.swing.table.*;
public class student   {
public static void main(String[] args) {
        Connection con = null;
    String url = "jdbc:mysql://localhost:3306/";
    String db = "ravic";
    String driver = "com.mysql.jdbc.Driver";
    String user = "root";
    String pass = "";
    try{
      Class.forName(driver).newInstance();
      con = DriverManager.getConnection(url+db, user, pass);
      try{
        Statement st = con.createStatement();
       ResultSet result = st.executeQuery("SELECT * FROM student1");
DefaultTableModel tableModel;
Vector data = new Vector();
Vector row;
ResultSetMetaData md = result.getMetaData();
int columnCount = md.getColumnCount();
Vector columns = new Vector(columnCount);
tableModel = new DefaultTableModel(data,columns);
tableModel.setRowCount(0);
tableModel.setColumnCount(0);
JTable table = new JTable(tableModel);
 
//store column names
for(int i=1; i<=columnCount; i++)
{
tableModel.addColumn(md.getColumnName(i));
//columns.add(md.getColumnName(i));
}
 
//store row data
while(result.next())
{
row = new Vector(columnCount);
 //Object[] row = new Object[columns];
for(int i=1; i<=columnCount; i++)
{//row[i - 1] = result.getObject(i);
row.add(result.getString(i));
}
tableModel.addRow(row);
//data.add(row);
}
 
  JFrame frame = new JFrame("Creating JTable Component 
 
Example!");
    JPanel panel = new JPanel();
    
   JScrollPane pane = new JScrollPane(table);
 panel.add(pane);
JTableHeader header = table.getTableHeader();
 header.setBackground(Color.yellow);
 panel.setForeground(java.awt.Color.lightGray);
        panel.setBackground(new java.awt.Color (0, 0, 64));
      frame.add(panel);
    frame.setSize(300,200);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        con.close();
      }
      catch (SQLException s){
        System.out.println("SQL code does not execute.");
      }    
    }
    catch (Exception e){
      e.printStackTrace();
    }
  }
}

[Rob Spoor]

What is it doing what you don't want, or not doing what you want?

I've tried your code (just changed the database details of course) and it worked just fine.

[ravic johnson]

i want to say to populate a jTable with mysql data after clicking a JButton
this coding i have given will run quit good without clicking a JButton
that is to run :java student
but i want to populate a JTable with mysql database data after clicking a Jbutton
here JButton implements a actionlistener on clicking a new interface should open
that i want to say
please help

[Rob Spoor]

Well, you know how to fill a DefaultTableModel with your data know. So all you need to do is put that part of the code in your action listener, and when it's done call table.setModel(tableModel).

You will notice that your program seems to be hanging while your table model is being filled. For the reason and a solution check JProgressBat Doesn't Update. In short, all the filling code should be put in a different thread, and when it's done the "table.setmodel(tableModel)" call should be on the Event Dispatcher Thread.

An easy way is using javax.swing.SwingWorker:

class JDBCSwingWorker extends SwingWorker<Object,Object[]>
{
    private JTable table;
 
    private DefaultTableModel tableModel;
 
    public JDBCSwingWorker(JTable table)
    {
        this.table = table;
    }
 
    protected Object doInBackground()
    {
        tableModel = new DefaultTableModel();
        // create the connection, set the columns, add the rows etc.
    }
 
    protected void done()
    {
        table.setModel(tableModel);
    }
}

You could have the loading seem more dynamic using publish and process but let's keep it simple for now.

[ravic johnson]

yes i am to able to know how to fill the defaulttablemodel with data
but i have tried putting that part of coding into java file that implements actionlistener but it yields errors
i am putting code here unchanged of that part includes JButton that after clicking i expects must proceed to show JTable with mysql data

import javax.swing.*;
import java.awt.event.*;
public class Supplier extends JFrame implements ActionListener{
 
 private JTextArea jTextArea1;
    private JTextPane jTextPane1;
    private JLabel jLabel1;
            private JButton getstatus;  
    public Supplier()
    {
        initComponents ();
 
    }
    private void initComponents() {
 
        JPanel panel=new JPanel();
 
 
       jTextArea1 = new JTextArea();
        getstatus=new JButton();
        
        jLabel1=new JLabel();
 
        panel.setLayout(null);
        setName("SUPPLIER Home Page");
        setTitle("SUPPLIER Home Page");
        panel.setForeground(java.awt.Color.lightGray);
        panel.setBackground(new java.awt.Color (0, 0, 64));
        jTextArea1.setLineWrap(true);
        jTextArea1.setBorder(new javax.swing.border.SoftBevelBorder(0));
        jTextArea1.setEditable(false);
        jTextArea1.setColumns(1);
        jTextArea1.setRows(2);
        jTextArea1.setForeground(java.awt.Color.lightGray);
        jTextArea1.setFont(new java.awt.Font ("Times New Roman", 1, 14));
        jTextArea1.setBackground(new java.awt.Color (0, 0, 64));
jTextArea1.setBounds(190, 100, 294, 140);//may be axis
        panel.add(jTextArea1);
        getstatus.setText("getstatus");
                    getstatus.setLocation(500,280);
                     getstatus.setSize(getstatus.getPreferredSize());
panel.add(getstatus);
 
 
getstatus.addActionListener(this);
        jLabel1.setBorder(new javax.swing.border.LineBorder(java.awt.Color.black, 4));
        jLabel1.setName("lblTitle");
        jLabel1.setText("SUPPLY CHAIN SYSTEM");
        jLabel1.setForeground(java.awt.Color.white);
        jLabel1.setBackground(new java.awt.Color (0, 0, 64));
        jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        jLabel1.setFont(new java.awt.Font ("Helvetica", 1, 18));
jLabel1.setBounds(80, 30, 340, 40);
        panel.add(jLabel1);
        getContentPane().add(panel);
        setVisible(true);
        setSize(575,475);
    }
public void actionPerformed(ActionEvent e)
{
JButton button= (JButton)e.getSource();

              if (button.equals(getstatus)) 
               {
                           new student(); 
                           this.dispose();
                   }    
               
 
}
}

can you explain it how to implement it with this coding
please help
[ October 29, 2008: Message edited by: ravic johnson ]

[Rob Spoor]

Originally posted by ravic johnson:
but it yields errors

What errors?

[ravic johnson]

in class Supplier which coding i previously posted that implements actionlistener if i put that portion how to fill defaulttablemodel with data with coding changed is as follows

    
import javax.swing.*;
import java.awt.event.*;
public class Supplier extends JFrame implements ActionListener{
 
 private JTextArea jTextArea1; 
    private JTextPane jTextPane1;
    private JLabel jLabel1;
            private JButton getstatus;        
    public Supplier()
    {
        initComponents ();
 
    }
    private void initComponents() {
 
        JPanel panel=new JPanel();
       jTextArea1 = new JTextArea();
       
        getstatus=new JButton();
        
        jLabel1=new JLabel();
 
        panel.setLayout(null);
        setName("SUPPLIER Home Page");
        setTitle("SUPPLIER Home Page");
        panel.setForeground(java.awt.Color.lightGray);
 

        panel.setBackground(new java.awt.Color (0, 0, 64));
 

        jTextArea1.setLineWrap(true);
        jTextArea1.setBorder(new javax.swing.border.SoftBevelBorder(0));
        jTextArea1.setEditable(false);
        jTextArea1.setColumns(1);
        jTextArea1.setRows(2);
        jTextArea1.setForeground(java.awt.Color.lightGray);
        jTextArea1.setFont(new java.awt.Font ("Times New Roman", 1, 14));
        jTextArea1.setText("Supplier  supply raw materials to the producer. The main raw material will be EN-8 Rod  ");
 

        jTextArea1.setBackground(new java.awt.Color (0, 0, 64));
jTextArea1.setBounds(190, 100, 294, 140);//may be axis
        panel.add(jTextArea1);
 
        getstatus.setText("getstatus");
                    getstatus.setLocation(500,280);
                     getstatus.setSize(getstatus.getPreferredSize());
panel.add(getstatus);

getstatus.addActionListener(this);
 
        jLabel1.setBorder(new javax.swing.border.LineBorder(java.awt.Color.black, 4));
        jLabel1.setName("lblTitle");
        jLabel1.setText("SUPPLY CHAIN SYSTEM");
        jLabel1.setForeground(java.awt.Color.white);
        jLabel1.setBackground(new java.awt.Color (0, 0, 64));
        jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        jLabel1.setFont(new java.awt.Font ("Helvetica", 1, 18));
jLabel1.setBounds(80, 30, 340, 40);
 
        panel.add(jLabel1);
 
        getContentPane().add(panel);
        setVisible(true);
        setSize(575,475);
 

    }
 
TableModel model = new TableModel(data,columns);
 
JTable table = new JTable(model);
tableModel.setRowCount(0);
tableModel.setColumnCount(0);
ResultSetMetaData md = result.getMetaData();
int columnCount = md.getColumnCount();
 
 Vector columns = new Vector(columnCount);
 
//store column names
for(int i=1; i<=columnCount; i++)
{
tableModel.addColumn(md.getColumnName(i));
//columns.add(md.getColumnName(i));
}
Vector data = new Vector();
Vector row;
 
//store row data
while(result.next())
{
//row = new Vector(columnCount);
 Object[] row = new Object[columns];
for(int i=1; i<=columnCount; i++)
{row[i - 1] = result.getObject(i);
//row.add(result.getString(i));
}
tableModel.addRow(row);
//data.add(row);
}
 

public void actionPerformed(ActionEvent e)
{
 
JButton button= (JButton)e.getSource();
 
if(button.equals(getstatus))
{
 
new database();
this.dispose();
 
}
 
                
               
 

}
}

when compiled it results following errors
C:\jdk\bin>javac Supplier.java
Supplier.java:99: <identifier> expected
tableModel.setRowCount(0);
^
Supplier.java:100: <identifier> expected
tableModel.setColumnCount(0);
^
Supplier.java:107: illegal start of type
for(int i=1; i<=columnCount; i++)
^
Supplier.java:112: <identifier> expected
Vector data = new Vector();
^
Supplier.java:116: illegal start of type
while(result.next())
^
Supplier.java:151: <identifier> expected
}


please help

[Rob Spoor]

Just before "TableModel model = new TableModel(data,columns);" you close your method, so the rest is just dangling inside the class definition. And inside the class definition you cannot have statements.

[ravic johnson]

i have put the lines of code inside the method that is under initComponents method but it even it results error
/*
C:\jdk\bin>javac Supplier.java
Supplier.java:95: cannot find symbol
symbol : class ResultSetMetaData
location: class Supplier
ResultSetMetaData md = result.getMetaData();
^
Supplier.java:95: cannot find symbol
symbol : variable result
location: class Supplier
ResultSetMetaData md = result.getMetaData();
^
Supplier.java:98: javax.swing.table.TableModel is abstract; cannot be instantiat
ed
TableModel model = new TableModel(data,columns);
^
Supplier.java:103: cannot find symbol
symbol : class ResultSetMetaData
location: class Supplier
ResultSetMetaData md = result.getMetaData();
^
Supplier.java:103: cannot find symbol
symbol : variable result
location: class Supplier
ResultSetMetaData md = result.getMetaData();
^
Supplier.java:104: columnCount is already defined in initComponents()
int columnCount = md.getColumnCount();
^
Supplier.java:106: columns is already defined in initComponents()
Vector columns = new Vector(columnCount);
^
Supplier.java:114: data is already defined in initComponents()
Vector data = new Vector();
^
Supplier.java:115: row is already defined in initComponents()
Vector row;
^
Supplier.java:118: cannot find symbol
symbol : variable result
location: class Supplier
while(result.next())
^
Supplier.java:121: row is already defined in initComponents()
Object[] row = new Object[columns];
^
Supplier.java:121: incompatible types
found : java.util.Vector
required: int
Object[] row = new Object[columns];
^
Supplier.java:123: cannot find symbol
symbol : variable result
location: class Supplier
{row[i - 1] = result.getObject(i);
^
13 errors
*/
coding of supplier is as follows

   
import javax.swing.*;
import java.awt.event.*;
import javax.swing.table.*;
import java.util.*;
 
public class Supplier extends JFrame implements ActionListener{
 
    private JTextPane jTextPane1;
    private JLabel jLabel1;
            private JButton getstatus;
       
            
 
    public Supplier()
    {
        initComponents ();
 
    }
 

    private void initComponents() {
 
        JPanel panel=new JPanel();
 

       jTextArea1 = new JTextArea();
               getstatus=new JButton();
        
        jLabel1=new JLabel();
 
        panel.setLayout(null);
        setName("SUPPLIER Home Page");
        setTitle("SUPPLIER Home Page");
        panel.setForeground(java.awt.Color.lightGray);
 

        panel.setBackground(new java.awt.Color (0, 0, 64));
 

        jTextArea1.setBackground(new java.awt.Color (0, 0, 64));
jTextArea1.setBounds(190, 100, 294, 140);//may be axis
        panel.add(jTextArea1);
 

 

        getstatus.setText("getstatus");
                    getstatus.setLocation(500,280);
                     getstatus.setSize(getstatus.getPreferredSize());
panel.add(getstatus);

getstatus.addActionListener(this);
 

 
        jLabel1.setBorder(new javax.swing.border.LineBorder(java.awt.Color.black, 4));
        jLabel1.setName("lblTitle");
        jLabel1.setText("SUPPLY CHAIN SYSTEM");
        jLabel1.setForeground(java.awt.Color.white);
        jLabel1.setBackground(new java.awt.Color (0, 0, 64));
        jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        jLabel1.setFont(new java.awt.Font ("Helvetica", 1, 18));
jLabel1.setBounds(80, 30, 340, 40);
 
        panel.add(jLabel1);
 
        getContentPane().add(panel);
        setVisible(true);
        setSize(575,475);
DefaultTableModel tableModel;
    Vector data = new Vector();
    Vector row;
    ResultSetMetaData md = result.getMetaData();
    int columnCount = md.getColumnCount();
    Vector columns = new Vector(columnCount);
TableModel model = new TableModel(data,columns);
 
JTable table = new JTable(model);
tableModel.setRowCount(0);
tableModel.setColumnCount(0);
ResultSetMetaData md = result.getMetaData();
int columnCount = md.getColumnCount();
 
 Vector columns = new Vector(columnCount);
 
//store column names
for(int i=1; i<=columnCount; i++)
{
tableModel.addColumn(md.getColumnName(i));
//columns.add(md.getColumnName(i));
}
Vector data = new Vector();
Vector row;
 
//store row data
while(result.next())
{
//row = new Vector(columnCount);
 Object[] row = new Object[columns];
for(int i=1; i<=columnCount; i++)
{row[i - 1] = result.getObject(i);
//row.add(result.getString(i));
}
tableModel.addRow(row);
//data.add(row);
}
 table.setModel(tableModel);
 
    }
 
public void actionPerformed(ActionEvent e)
{
 
JButton button= (JButton)e.getSource();
 
if(button.equals(getstatus))
{
 
new student();
this.dispose();
 
}                             
}
}
 

i again want to say that i want to populate a JTable with mysql data after clicking JButton
can you please explain what you have advised

Well, you know how to fill a DefaultTableModel with your data know. So all you need to do is put that part of the code in your action listener, and when it's done call table.setModel(tableModel).

i am quite new to swing and AWT concepts

please help i want to submit this project in the first week of November

[Rob Spoor]

Those errors are quite basic. You should start by importing the right classes. Also, you should create a new DefaultTableModel. TableModel itself is an interface.

[ravic johnson]

i want to ask what is the concept behind putting defaulttablemodel with data in the part (supplier java file) which implements action listener
please explain