想必你是初学者，为了让你更好的理解看一下这个程序吧

import java.awt.BorderLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextField;

public class Moble extends JFrame {

// Java实现一个简单的手机面板及数字输入功能

private static final long serialVersionUID = 1L;

private JTextField txtView;

public static void main(String args[]) {

new Moble();

}

public Moble() {

setTitle("Moble");

setBounds(100, 100, 200, 300);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

final JPanel panel = new JPanel();

getContentPane().add(panel, BorderLayout.CENTER);

setResizable(false);

txtView = new JTextField();

panel.setLayout(null);

panel.add(txtView);

final JButton btn1 = new JButton();

btn1.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("1"));

}

});

btn1.setText("1");

btn1.setBounds(0, 73, 59, 23);

panel.add(btn1);

final JButton btn2 = new JButton();

btn2.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("2"));

}

});

btn2.setText("2");

btn2.setBounds(65, 73, 59, 23);

panel.add(btn2);

final JButton btn3 = new JButton();

btn3.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("3"));

}

});

btn3.setText("3");

btn3.setBounds(130, 73, 59, 23);

panel.add(btn3);

final JButton btn4 = new JButton();

btn4.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("4"));

}

});

btn4.setText("4");

btn4.setBounds(0, 102, 59, 23);

panel.add(btn4);

final JButton btn5 = new JButton();

btn5.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("5"));

}

});

btn5.setText("5");

btn5.setBounds(65, 102, 59, 23);

panel.add(btn5);

final JButton btn6 = new JButton();

btn6.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("6"));

}

});

btn6.setText("6");

btn6.setBounds(130, 102, 59, 23);

panel.add(btn6);

final JButton btn7 = new JButton();

btn7.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("7"));

}

});

btn7.setText("7");

btn7.setBounds(0, 131, 59, 23);

panel.add(btn7);

final JButton btn8 = new JButton();

btn8.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("8"));

}

});

btn8.setText("8");

btn8.setBounds(65, 131, 59, 23);

panel.add(btn8);

final JButton btn9 = new JButton();

btn9.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("9"));

}

});

btn9.setText("9");

btn9.setBounds(130, 131, 59, 23);

panel.add(btn9);

final JButton btn0 = new JButton();

btn0.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText(txtView.getText().concat("0"));

}

});

btn0.setText("0");

btn0.setBounds(68, 160, 57, 23);

panel.add(btn0);

txtView = new JTextField();

txtView.setBounds(59, 24, 90, 21);

panel.add(txtView);

final JButton btnSend = new JButton();

btnSend.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

if (txtView.getText().indexOf("calling...") == -1) {

txtView.setText(txtView.getText().concat("calling..."));

} else {

return;

}

}

});

btnSend.setText("Send");

btnSend.setBounds(40, 189, 127, 23);

panel.add(btnSend);

final JButton btnclear = new JButton();

btnclear.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

txtView.setText("");

}

});

btnclear.setText("Clear");

btnclear.setBounds(40, 212, 127, 23);

panel.add(btnclear);

final JButton btnOff = new JButton();

btnOff.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

System.exit(0);

}

});

btnOff.setText("Exit");

btnOff.setBounds(40, 232, 127, 23);

panel.add(btnOff);

setVisible(true);

}

}