Placing and resizing JPanel in JFrame

Question

I want to have a JFrame with a JPanel that looks like this.

The 2 panels on the left side 60% width and 50% height each then the panel on the right side 40% width and 100% height How can I achieve this?

  import javax.swing.*;
  import java.awt.*;
   public class INV{

private JFrame mainFrame;
private JPanel Outer_panel1;
private JPanel Outer_panel2;
private JPanel Panel1;
private JPanel Panel2;
private JPanel Panel3;
private JPanel Panel4;
private JButton b1;
private JButton b2;
private JButton b3;
private JComboBox List;
private JComboBox List2;
private JTextField Item_name;
private JTextField Dec_qty;
private JTextField Inc_qty;
private static String[] Items = {"wood","steel"};
private JTable Table;
private JScrollPane Scroll;
static double xsize;
static double ysize;

    public INV(){
        gui();
    }

    public void gui(){
        mainFrame = new JFrame("sample");
        GridBagConstraints Con = new GridBagConstraints();

        //Left Panel
        Dec_qty=new JTextField(3); 
        Inc_qty=new JTextField(3); 
        List = new JComboBox(Items);
        List2 = new JComboBox(Items);
        b1 = new JButton("OK");
        b2 = new JButton("OK");


        Outer_panel1 = new JPanel(new GridBagLayout());
        Outer_panel1.setBackground(Color.yellow);

        Panel1 = new JPanel();
        Panel1.setBackground(Color.blue);
        Panel2 = new JPanel();
        Panel2.setBackground(Color.red);



        Outer_panel1.add(b1);
        Outer_panel1.add(b2);

        Panel1.add(List);
        Panel2.add(List2);
        Panel1.add(Inc_qty);
        Panel2.add(Dec_qty);
        Panel1.add(b1);
        Panel2.add(b2);

        Con.gridx = 0;
        Con.gridy = 0;
        Con.ipady = 300;
        Con.fill = GridBagConstraints.VERTICAL;
        Outer_panel1.add(Panel1,Con);
        Con.gridx = 0;
        Con.gridy = 1;
        Con.ipady = 0;
        Con.weighty = 1.0;
        Outer_panel1.add(Panel2,Con);


        mainFrame.add(Outer_panel1, BorderLayout.LINE_START);


        //right panel
        Outer_panel2 = new JPanel(new GridBagLayout());
        Outer_panel2.setBackground(Color.CYAN);

        Panel3 = new JPanel();
        Panel3.setBackground(Color.MAGENTA);
        Panel4 = new JPanel();
        Panel4.setBackground(Color.ORANGE);

        //Panel3
        Item_name =new JTextField(20); 
        b3 = new JButton("Search");

        //Panel4 and Table
        String[] columnNames = {"column1","column2"};
        Object[][] data = {{"sample1","sample2"},
                            {"sample3","sample4"}};

        Table = new JTable(data, columnNames);
        Table.setPreferredScrollableViewportSize(new Dimension(200,200));
        Table.setFillsViewportHeight(true);
        Scroll = new JScrollPane(Table);

        Panel3.add(Item_name);
        Panel3.add(b3);
        Panel4.add(Scroll);

        Con.gridx = 0;
        Con.gridy = 0;
        Con.ipady = 0;
        Con.weighty = 0;
        Outer_panel2.add(Panel3, Con);
        Con.gridx = 0;
        Con.gridy = 1;
        Con.ipady = 0;  
        Con.fill = GridBagConstraints.BOTH;
        Con.weighty = 1.0;

        Outer_panel2.add(Panel4, Con);
        mainFrame.add(Outer_panel2, BorderLayout.EAST);

        mainFrame.setVisible(true);
        mainFrame.setSize(900, 500);
        mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }


public static void main(String[] args){
    new INV();
}
}

Answer 1

You should never control the size manually. What if the user wants to resize?? You wilk have to do useless computations while java will happily do it for you using layout manager.

http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html

Answer 2

JFrame frame = new JFrame();
frame.setLayout(null);
frame.setSize(600, 400);

JPanel panel1 = new JPanel();
panel1.setBounds(0, 0, 400, 200);
panel1.setBackground(Color.YELLOW);
panel1.setLayout(null);

JPanel panel2 = new JPanel();
panel2.setBounds(400, 0, 200, 400);
panel2.setBackground(Color.RED);
panel2.setLayout(null);

JPanel panel3 = new JPanel();
panel3.setBounds(0, 0, 600, 400);
panel3.setBackground(Color.BLACK);
panel3.setLayout(null);

panel3.add(panel1);
panel3.add(panel2);
frame.add(panel3);

//YOU CAN USE  LAYOUT = NULL TO MANUALLY POSITION YOUR PANELS
//IT IS BEST TO USE LAYOUT MANAGERS, BUT SETTING THE POSITIONS MANUALLY IS THE EASIEST
//SPECIALLY IF YOU WILL JUST .setResizable(false)