java swing borderlayout adding panes difficulties-CodePudding

so basically, when I add two panes to container with BorderLayout I have a something like padding and I have no idea how to fix it

below the code is a pic of what I mean

        Container mainContainer = this.getContentPane(); //
        mainContainer.setLayout(new BorderLayout(8, 6));
        mainContainer.setBackground(Color.BLACK);
        this.getRootPane().setBorder(BorderFactory.createMatteBorder(4, 4, 4, 4, Color.CYAN));

        JPanel panelZTekstem = new JPanel();
        panelZTekstem.setBackground(Color.ORANGE);
        poleTekstowe.setEditable(false);
        poleTekstowe.setText("0");
        poleTekstowe.setSize(400, 100);
        poleTekstowe.setOpaque(true);
        poleTekstowe.setFont(new Font("MV Boli", Font.BOLD, 20));
        poleTekstowe.setHorizontalAlignment(JTextField.RIGHT);
        panelZTekstem.setLayout(new FlowLayout());
        panelZTekstem.add(poleTekstowe);
        mainContainer.add(panelZTekstem,BorderLayout.NORTH);

        JPanel panelZLiczbami = new JPanel();

        for (int i = 0; i <= 16; i  ) {
            JButton test = new JButton();
            panelZLiczbami.add(test);
        }

        panelZLiczbami.setBackground(Color.BLUE);
        mainContainer.add(panelZLiczbami, BorderLayout.CENTER);

CodePudding user response：

when I add two panes to container with BorderLayout I have a something like padding

mainContainer.setLayout(new BorderLayout(8, 6));

What did you think the 8/6 values are used for?

You are creating a gap between the components.

It is best to read the API to understand how the parameters are used.