How to Add Jtable in Jpanel With Null Layout

JTable in JPanel Not Displaying

NEVER do this:

scroll.setLayout(null);

You ruin the JScrollPane's layout, and so it completely loses its functionality, thereby shooting yourself in the foot. Remove that line.

While null layouts and setBounds() might seem to Swing newbies like the easiest and best way to create complex GUI's, the more Swing GUI'S you create the more serious difficulties you will run into when using them. They won't resize your components when the GUI resizes, they are a royal witch to enhance or maintain, they fail completely when placed in scrollpanes, they look gawd-awful when viewed on all platforms or screen resolutions that are different from the original one.

For example, this GUI

is created by this code:

import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;

public class TableIssues2 extends JPanel {
    private static final int GAP = 5;
    private static final String[] COL_NAMES = {"One", "Two", "Three"};
    private DefaultTableModel model = new DefaultTableModel(COL_NAMES, 0);
    private JTable patientsTable = new JTable(model);

    public TableIssues2() {
        JPanel buttonPanel = new JPanel(new GridLayout(1, 0, GAP, GAP));
        buttonPanel.add(new JButton("Add"));
        buttonPanel.add(new JButton("Remove"));
        buttonPanel.add(new JButton("Exit"));

        JPanel bottomPanel = new JPanel();
        bottomPanel.add(buttonPanel);

        for (int i = 0; i < 5; i++) {
            model.addRow(new String[]{"First", "Second", "Third"});
        }
        setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
        setLayout(new BorderLayout(GAP, GAP));
        add(new JScrollPane(patientsTable), BorderLayout.CENTER);
        add(bottomPanel, BorderLayout.PAGE_END);
    }

    private static void createAndShowGui() {
        TableIssues2 mainPanel = new TableIssues2();

        JFrame frame = new JFrame("TableIssues2");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGui();
            }
        });
    }
}

Unable to show JTable in JPanel from dynamically retrieved data

This is based on what cmickr and Andrew Thompson posted. I modified the following functions to work.

public void setReferencePanel(ArrayList<Item> items, String refFile) {
    DefaultTableModel model = new DefaultTableModel(vectorize(items), makeHeaderVector());
    refTable.setModel(model);
    refListingPanel.setBorder(BorderFactory.createTitledBorder("Reference File - " + refFile));
}

private Vector vectorize(ArrayList<Item> items) {
    Vector results = new Vector();
    for (int i = 0; i < items.size(); i++) {
        results.addElement(items.get(i).vectorize());
    }
    return results;
}

private Vector makeHeaderVector() {
    String[] cols = { ... }; // hid application specific string array
    Vector<String> results = new Vector<String>(Arrays.asList(cols));
    return results;
}

This is my basic understanding of vectors, since I do not use them much. Also, this may not be the fastest way of approaching the problem, but my first goal is to get it working, then improve it. The important part was to use a TableModel, in my case DefaultTableModel, and then setModel() of the the JTable to the new model, like was referenced.

JTable for JPanel with multiple type JComponent (Swing)

objectMatrix[0][0] = new PanelSpinnerRadioButton();

• Should be set PanelSpinnerRadioButtonData to the TableModel, rather than a component such as PanelSpinnerRadioButton.

output = new PanelSpinnerRadioButton((PanelSpinnerRadioButtonData)value);

• It is a waste to create each time a component in the TableCellRenderer#getTableCellRendererComponent(...).

import java.awt.*;
import javax.swing.*;
import javax.swing.table.*;

public class TableTest {
  public JComponent makeUI() {
    String[] hdrsObjects = {"PanelSpinnerRadioButton Class Column"};
    Object[][] objectMatrix = new Object[3][hdrsObjects.length];
    objectMatrix[0][0] = new PanelSpinnerRadioButtonData(false, 10, 40);
    objectMatrix[1][0] = new PanelSpinnerRadioButtonData(true,  20, 40);
    objectMatrix[2][0] = new PanelSpinnerRadioButtonData(false, 30, 40);

    JTable table = new JTable(new DefaultTableModel(objectMatrix, hdrsObjects));
    table.setRowHeight(30);

    TableColumn tc = table.getColumn("PanelSpinnerRadioButton Class Column");
    tc.setCellRenderer(new PSRBTableCellRenderer());
    tc.setCellEditor(new PSRBTableCellEditor());

    JPanel p = new JPanel(new BorderLayout());
    p.add(new JScrollPane(table));
    return p;
  }
  public static void main(String... args) {
    EventQueue.invokeLater(() -> {
      try {
        for (UIManager.LookAndFeelInfo laf: UIManager.getInstalledLookAndFeels()) {
          if ("Nimbus".equals(laf.getName())) {
            UIManager.setLookAndFeel(laf.getClassName());
          }
        }
      } catch (Exception e) {
        e.printStackTrace();
      }
      JFrame f = new JFrame();
      f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
      f.getContentPane().add(new TableTest().makeUI());
      f.setSize(240, 240);
      f.setLocationRelativeTo(null);
      f.setVisible(true);
    });
  }
}

class PanelSpinnerRadioButtonData {
  private boolean opt02 = false;
  private Integer from = 0;
  private Integer size = 1;

  PanelSpinnerRadioButtonData() {
    this(false, 5, 10);
  }
  PanelSpinnerRadioButtonData(boolean opt02, Integer from, Integer size) {
    this.opt02 = opt02;
    this.from = from;
    this.size = size;
  }
  public boolean getOption() {
    return opt02;
  }
  public Integer getFrom() {
    return from;
  }
  public Integer getSize() {
    return size;
  }
}

class PanelSpinnerRadioButton extends JPanel {
  public final JRadioButton jrbOption01 = new JRadioButton("01");
  public final JRadioButton jrbOption02 = new JRadioButton("12");
  public final JSpinner jspnValues = new JSpinner(new SpinnerNumberModel(5, 0, 10, 1));

  private final JPanel panel = new JPanel();

  PanelSpinnerRadioButton() {
    this(new PanelSpinnerRadioButtonData(false, 20, 40));
  }

  PanelSpinnerRadioButton(PanelSpinnerRadioButtonData data) {
    super();

    panel.setLayout(new BoxLayout(panel, BoxLayout.LINE_AXIS));
    panel.add(jrbOption01);
    panel.add(jrbOption02);
    panel.add(Box.createRigidArea(new Dimension(5, 0)));
    panel.add(new JSeparator(JSeparator.VERTICAL));
    panel.add(Box.createRigidArea(new Dimension(5, 0)));
    panel.add(jspnValues);
    ButtonGroup bg = new ButtonGroup();
    bg.add(jrbOption01);
    bg.add(jrbOption02);
    ((SpinnerNumberModel) jspnValues.getModel()).setMaximum(data.getSize());
    setData(data);

    init();
  }

  private void init() {
    setLayout(new BoxLayout(this, BoxLayout.LINE_AXIS));
    setBackground(new Color(0, 0, 0, 0));
    add(panel);
  }

  public void setData(PanelSpinnerRadioButtonData data) {
    if (data.getOption()) {
      jrbOption02.setSelected(true);
    } else {
      jrbOption01.setSelected(true);
    }
    ((SpinnerNumberModel) jspnValues.getModel()).setValue(data.getFrom());
  }

  // Used in PSRBTableCellEditor.getCellEditorValue()
  public PanelSpinnerRadioButtonData getData() {
    return new PanelSpinnerRadioButtonData(
             jrbOption02.isSelected(),
             (Integer) ((SpinnerNumberModel) jspnValues.getModel()).getValue(),
             (Integer) ((SpinnerNumberModel) jspnValues.getModel()).getMaximum());
  }
}

class PSRBTableCellRenderer implements TableCellRenderer {
  private final PanelSpinnerRadioButton renderer = new PanelSpinnerRadioButton();
  @Override public Component getTableCellRendererComponent(
      JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
    if (value instanceof PanelSpinnerRadioButtonData) {
      renderer.setData((PanelSpinnerRadioButtonData) value);
    }
    return renderer;
  }
}

class PSRBTableCellEditor extends AbstractCellEditor implements TableCellEditor {
  private final PanelSpinnerRadioButton editor = new PanelSpinnerRadioButton();
  @Override public Object getCellEditorValue() {
    return editor.getData();
  }
  @Override public Component getTableCellEditorComponent(
      JTable table, Object value, boolean isSelected, int row, int column) {
    if (value instanceof PanelSpinnerRadioButtonData) {
      editor.setData((PanelSpinnerRadioButtonData) value);
    }
    return editor;
  }
}

JPanel with null layout in JScrollPane - don't see elements

Although I agree completely with @Frakcool about null layout, the problem you are facing has a different source. You should not add components directly into JScrollPane, but into JScrollPane's ViewPort.

The line mainScroll.add(container); should be mainScroll.getViewport().add(container);

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