JTextField的。 JPanel设置位置gui java

Question

我正在使用JTable（AbstractTableModel）。实际上我有三个表模型来显示并通过单击按钮填充表模型。 现在我想使用jtextfield添加，更新和删除数据。

这是我的GUI：

import java.sql.SQLException;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.event.*;
import java.util.*;
public class Main
{
// JFrame
private JFrame fr = new JFrame("JTable Biblioteca");
// JPanels
private JPanel p = new JPanel();
private JPanel pl = new JPanel();
private JPanel pc = new JPanel();
private JPanel pp = new JPanel();
private JPanel pwest = new JPanel();
private JPanel pabajo = new JPanel();
private JPanel plib = new JPanel();
// JTextFields
private JTextField DescripcionjTextField1;
private JTextField CantidadjTextField2;
private JTextField EdicionjTextField3;
private JTextField ObservacionjTextField4;
// TableModels
private TableModel tm = new TableModel();
private TableModelCliente tmc = new TableModelCliente();
private TableModelPrestamo tmp = new TableModelPrestamo();
// JTables
private JTable tableLibros = new JTable(tm);
private JTable tableClientes = new JTable(tmc);
private JTable tablePrestamos = new JTable(tmp);
// JButtons
private JButton btnRefresh = new JButton("Refresh");
private JButton btnAddl = new JButton("Agregar");
private JButton btnUpdatel = new JButton("Actualizar");
private JButton btnDeletel = new JButton("Eliminar");

private JLabel label1 = new JLabel("Descripción");


// hago que el ScrollPane esté siempre visible
private JScrollPane sc = new JScrollPane(tableLibros, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
                                              ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
private JScrollPane scc = new JScrollPane(tableClientes, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
                                              ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
private JScrollPane scp = new JScrollPane(tablePrestamos, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
                                              ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);                                           

public Main(){
    // indico en cada JTable que voy a hacer seleccion simple de filas (no multiple)
    tableLibros.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    tableClientes.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    tablePrestamos.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

    p.setLayout(new GridLayout(1,3));
    pl.setLayout(new BorderLayout()); // panel libro
    pc.setLayout(new BorderLayout()); // panel cliente
    pp.setLayout(new BorderLayout()); // panel prestamo

    // jtables
    pl.add("Center", sc);
    pc.add("Center", scc);
    pp.add("Center", scp);

    // títulos
    pl.add("North", new JLabel("Libros"));
    pc.add("North", new JLabel("Clientes"));
    pp.add("North", new JLabel("Préstamos"));

    p.add(pl);
    p.add(pc);
    p.add(pp);

    pwest.add(btnRefresh);
    pabajo.add(btnAddl);
    pabajo.add(btnUpdatel);
    pabajo.add(btnDeletel);
    fr.add("Center", p);
    fr.add("West", pwest);
    fr.add("South", pabajo);

    // eventos
    fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    btnRefresh.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e){
            try{
                tm.refresh();
                tm.fireTableDataChanged();
                tmc.refreshCli();
                tmc.fireTableDataChanged();
            } 
                catch(ClassNotFoundException f){System.out.println("Exception");}
                catch(InstantiationException f){System.out.println("Exception");}
                catch(IllegalAccessException f){System.out.println("Exception");}
                catch(SQLException f){System.out.println("Exception");
            }
        }
    });

    btnAddl.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e){
        }
    });

    fr.setSize(1200, 500);
    fr.setVisible(true);
}

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

结果是： “show jtables”

我想显示JTextField向下按钮