为什么我的不显示按钮

package lianxi;

import javax.swing.SwingUtilities;
import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JFrame;
import javax.swing.JTextPane;
import javax.swing.JTextArea;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import java.awt.GridBagConstraints;
import java.awt.FlowLayout;
import java.awt.event.*;
import java.io.*;

public class Ftest1 extends JFrame {

    private static final long serialVersionUID=1L;
    private JPanel jContentPane=null;
    private JTextArea jTextArea=null;
    private JPanel controlPanel=null;
    private JButton openButton=null;
    private JButton colesButton=null;

    private JTextArea getJTextArea() {
        if (jTextArea == null) {
            jTextArea = new JTextArea();
        }
        return jTextArea;
    }
    private JPanel getControlPanel() {
        if (controlPanel == null) {
            FlowLayout flowLayout = new FlowLayout();
            flowLayout.setVgap(1);
            controlPanel = new JPanel();
            controlPanel.setLayout(flowLayout);
            controlPanel.add(getOpenButton(), null);
            controlPanel.add(getCloseButton(), null);
        }
        return controlPanel;
    }

    private JButton getOpenButton(){
        if(openButton==null){
            openButton=new JButton();
            openButton.setText("写入文件");
            openButton.addActionListener(new java.awt.event.ActionListener(){
                public void actionPerformed(java.awt.event.ActionEvent e){
                    File file=new File("word.txt");

                    try {
                        FileWriter out= new FileWriter(file);
                        String s=jTextArea.getText();
                        out.write(s);
                        out.close();
                    } catch (IOException e1) {
                        // TODO Auto-generated catch block
                        e1.printStackTrace();
                    }
                }

            });

        }
        return openButton;

    }

    private JButton getCloseButton(){
        if(openButton==null){
            openButton=new JButton();
            openButton.setText("读取文件");
            openButton.addActionListener(new java.awt.event.ActionListener(){
                public void actionPerformed(java.awt.event.ActionEvent e){
                    File file=new File("word.txt");
                    try {
                        FileReader in=new FileReader(file);

                        char byt[]=new char[1024];
                        int len=in.read(byt);
                        jTextArea.setText(new String(byt,0,len));
                        in.close();
                    } catch (IOException e1) {
                        // TODO Auto-generated catch block
                        e1.printStackTrace();
                    }
                }

            });

        }
        return openButton;

    }

    public Ftest1(){
        super();
        initialize();
    }

    private void initialize(){
        this.setSize(300,200);
        this.setContentPane(getJContentPane());
        this.setTitle("JFrame");
    }

    private JPanel getJContentPane(){
        if(jContentPane==null){
            jContentPane=new JPanel();
            jContentPane.setLayout(new BorderLayout());
            jContentPane.add(getJTextArea(), BorderLayout.CENTER);
            jContentPane.add(getContentPane(),BorderLayout.SOUTH);
        }
        return jContentPane;
    }

    public static void main(String[] args) {
        Ftest1 thisClass=new Ftest1();
        thisClass.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        thisClass.setVisible(true);

    }

}

应该是上图结果我的为什么是下面这

个图