1 文件名：Calculate_GUI。java
import javax。swing。*;
import  t。Container;
import  t。event。*;
public class Calculate_GUI extends JFrame{
	private JPanel p1;
	private JButton keyButton[]=new JButton[16],signButton,clearButton,deleteButton;
	private JTextField outputField;
  private Container contentPane;
  private boolean firstInput=true;
  private Calculate_Model model=new Calculate_Model();
  
  public Calculate_GUI(){
  	p1=new JPanel();
  	keyButton[0]=new JButton("1");
  	keyButton[1]=new JButton("2");
  	keyButton[2]=new JButton("3");
  	keyButton[3]=new JButton("/");
  	keyButton[4]=new JButton("4");
  	keyButton[5]=new JButton("5");
  	keyButton[6]=new JButton("6");
  	keyButton[7]=new JButton("*");
  	keyButton[8]=new JButton("7");
  	keyButton[9]=new JButton("8");
  	keyButton[10]=new JButton("9");
  	keyButton[11]=new JButton("-");
  	keyButton[12]=new JButton("0");
  	keyButton[13]=new JButton("。
  ");
  	keyButton[14]=new JButton("=");
  	keyButton[15]=new JButton("+");
  	clearButton=new JButton("c");
  	signButton=new JButton("+/-");
  	deleteButton=new JButton("←");
  	outputField=new JTextField(15);
  	  tText("0");
  	  tEditable(false);
  	contentPane= tContentPane();
  	
  	 tSize(250,250);
  	 tLayout(new  t。
  GridLayout(4,5));
  	for(int i=0;i  setFont(new  t。Font("Dialog",1,16));
  		 d(keyButton[i]);
  	}
  	 d(outputField, t。BorderLayout。NORTH);
  	 d(p1, t。
  BorderLayout。CENTER);
  	 ow();
  }
  public void registEvent(){
  	 dWindowListener(new WindowAdapter(){
  		public void windowClosing(WindowEvent we){System。
  exit(0);}
  	});
  	for(int i=0;i  equals("0"))firstInput=true;
  		}
  	});
  	 dActionListener(new ActionListener(){
  		public void actionPerformed(ActionEvent ae){
  			firstInput=true;
  			 tText("0");
  			 set();
  		}
  	});
  }
  
  class keyButtonHandler implements ActionListener{
  	public void actionPerformed(ActionEvent ae){
  		char actionCommand= tActionCommand()。
  charAt(0);
  		switch(actionCommand){
  			case '1':case '2':case '3':case '4':case '5': case '6':case '7':case '8':case '9':case '0':case '。
  ':
  			  if(firstInput){ tText( lueOf(actionCommand));firstInput=false;}
  			  else  tText( tText()+actionCommand);
  			  break;
  			case '+':case '-':case '*':case '/':
  			  if(firstInput) tOperate(actionCommand);
  			  else{
  			  	 tOperateNumber( rseDouble( tText()));
  			  	 lculating();
  			  	 tOperate(actionCommand);
  			  	 tText( lueOf( tResult()));
  			  	firstInput=true;
  			  }
  			  break;
  			case '=':
  			  if(firstInput){
  			  	 lculating();
  			  	 tText( lueOf( tResult()));
  			  }
  			  else{
  			  	 tOperateNumber( rseDouble( tText()));
  			  	 lculating();
  			  	 tText( lueOf( tResult()));
  			  	firstInput=true;
  			  }
  }	}	}
  
  public static void main(String args[]){
  	new Calculate_GUI()。
  registEvent();
  }
}
2    文件名 Calculate_Model。java
public class Calculate_Model{
	private double result;
	private double operateNumber;
	private char operate;
	
	public Calculate_Model(){
		result=0;
		operateNumber=0;
		operate=' ';
	}
	
	public void setResult(double n){
		result=n;
	}
	public void setOperate(char o){
		operate=o;
	}
	public void setOperateNumber(double n){
		operateNumber=n;
	}
	public double getResult(){
		return result;
	}
	public void calculating(){
		switch(operate){
			case ' ':result=operateNumber;break;
			case '+':result+=operateNumber;break;
			case '-':result-=operateNumber;break;
			case '*':result*=operateNumber;break;
			case '/':result/=operateNumber;break;
		}
	}
	public void reset(){
		result=0;
		operateNumber=0;
		operate=' ';
	}
	public double toSign(double n){
		return 0-(n-0);
	}
	public String backSpace(String n){
		String reResult="0";
		try{
			reResult= bstring(0,n。
  length()-1);
			 rseDouble(reResult);
		}
		catch(NumberFormatException e){reResult="0";} 
		return reResult;
	}		
}
两个文件同一目录；
javac Calculate_GUI。
  java
javac Calculate_Model。java
java Calculate_GUI。