Eclipse JAVA 计算器源码 适合初学者

package javatest;
import java.awt.Frame;
import java.awt.TextField;
import java.awt.Rectangle;
import java.awt.Button;
import java.awt.ComponentOrientation;
import java.awt.Dimension;
import javax.swing.JComponent;
import javax.swing.JToolTip;
import javax.swing.ToolTipManager;
public class computer extends Frame {
private static final long serialVersionUID = 1L;
 public TextField textField = null;
 public Button button = null;
 private Button button1 = null;
 private Button button2 = null;
 private Button button3 = null;
 private Button button4 = null;
 private Button button5 = null;
 private Button button6 = null;
 private Button button7 = null;
 private Button button8 = null;
 private Button button9 = null;
 private Button button10 = null;
 private Button button11 = null;
 private Button button12 = null;
 private Button button13 = null;
 private Button button14 = null;
 private Button button15 = null;
 private TextField textField1 = null;

 private TextField textField2 = null;
 private TextField textField3 = null;
 private Button button16 = null;
 /**
  * This method initializes textField 
  *  
  * @return java.awt.TextField 
  */
 private TextField getTextField() {
  if (textField == null) {
   textField = new TextField();
   textField.setBounds(new Rectangle(45, 30, 226, 16));
   textField.setComponentOrientation(ComponentOrientation.UNKNOWN);
   textField.setName("textfield");
   
   
   
   
  }
  return textField;
 }

 /**
  * This method initializes button 
  *  
  * @return java.awt.Button 
  */
 private Button getButton() {
  if (button == null) {
   button = new Button();