calculator.java

实现了WINDOWS计算器的所有功能,界面和WINDOWS的一莫一样,这是不完善版本,

   }
   /*********************************************/
   
  /*********************************************************/
// 对运算符的计算+jb[49].-jb[43].*jb[37]./jb[31]
   if(e.getSource()==jb[49]&&(("+-*/=^.(").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)&&!textField1.getText().equals("0."))//"+"呵呵有点长。可设一个变量来判断
   {
	   textField1.setText(textField1.getText()+"+");	                   
   }
   if(e.getSource()==jb[43]&&(("+-*/=^.(").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)&&!textField1.getText().equals("0."))//"-"
   {
	   textField1.setText(textField1.getText()+"-");	
   }
   if(e.getSource()==jb[37]&&(("+-*/=^.(").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)&&!textField1.getText().equals("0."))//"*"
   {
	   textField1.setText(textField1.getText()+"*");   
   }
   if(e.getSource()==jb[31]&&(("+-*/=^.(").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)&&!textField1.getText().equals("0."))//"/"
   {
	   textField1.setText(textField1.getText()+"/");
   }
  
   /***_________________________________________位运算~!|&>><<________________________________________________________________*******/
   if(e.getSource()==jb[51]&&(("+-*/=^.()<>sEng").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)&&!textField1.getText().equals("0."))//Int
   {
	                  textField1.setText(""+(int)(Double.parseDouble(textField1.getText()))+"");
   }
   if(e.getSource()==jb[45])//Not
   {
	   if(textField1.getText().equals("0."))//如果文本框中最初为”0.“这直接清零后再向其输入~
	   {
		   textField1.setText("");
	   textField1.setText(textField1.getText()+"~");
	   }
	   else if(!textField1.getText().equals("0.")&&("0123456789).!").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)//如果文本框中的内容不是“0.”且保证~符合不能直接跟在数字后面，及要让它跟在运算符后面
	   textField1.setText(textField1.getText()+"~");
	 
   }
   if(e.getSource()==jb[33]&&(("+-*/=^.(<>sEng").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)&&!textField1.getText().equals("0."))//And
   {
	   textField1.setText(textField1.getText()+"&");
   }
   if(e.getSource()==jb[32]&&(("+-*/=^.(<>sEng").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)&&!textField1.getText().equals("0."))//Mod
   {
	   textField1.setText(textField1.getText()+"%");
   }
   if(e.getSource()==jb[38]&&(("+-*/=^.(<>sEng").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)&&!textField1.getText().equals("0."))//Or
   {
	   textField1.setText(textField1.getText()+"|");
   }
   if(e.getSource()==jb[44]&&(("123456789").indexOf(textField1.getText().charAt(textField1.getText().length()-1))!=-1)&&!textField1.getText().equals("0."))//Lsh
   {
	   if(!jc1.isSelected())
	   textField1.setText(textField1.getText()+"<");
	   else
	   {
       textField1.setText(textField1.getText()+">");
	   }
   }
   if(e.getSource()==jb[39]&&(("+-*/=^.(<>sEng").indexOf(textField1.getText().charAt(textField1.getText().length()-1))==-1)&&!textField1.getText().equals("0."))//异或
   {
	   textField1.setText(textField1.getText()+"$");//这里乘方用了异或符号^，这里用$代替；
   }
 //----------------当用户按等号键以后对文本框中的计算式进行分析------------关键步骤
   
   if(e.getSource()==jb[50])
   {
	   Shiyan4 test = new Shiyan4();	   

	   try {
	textField1.setText(""+test.evaluate(textField1.getText()));
	} catch (Exception e1) {
		// TODO Auto-generated catch block
		JOptionPane.showMessageDialog(this,"请输入正确格式的计算式！","出错啦",0); 
//		e1.printStackTrace();
	}
   }
}
public void mouseClicked(MouseEvent arg0) {
	// TODO Auto-generated method stub
}

public void mouseEntered(MouseEvent arg0) {
	// TODO Auto-generated method stub	
}

public void mouseExited(MouseEvent arg0) {
	// TODO Auto-generated method stub
}

public void mousePressed(MouseEvent arg0) {
	// TODO Auto-generated method stub
	for(int i=0;i<=57;i++)	
		if(arg0.getSource()==jb[i]&&jb[i].isEnabled())
		    jb[i].setBorder(BorderFactory.createBevelBorder(1));	
}
public void mouseReleased(MouseEvent arg0) {
	// TODO Auto-generated method stub
	for(int i=0;i<=57;i++)	
		if(arg0.getSource()==jb[i]&&jb[i].isEnabled())	
		    jb[i].setBorder(BorderFactory.createBevelBorder(0));

}


//-----------三个内部类---------三个内部类---------------三个内部类---------三个内部类--------三个内部类----------三个内部类--------三个内部类--------三个内部类---------------------------//

//按Sta键后弹出的窗口
class MyDialog extends JFrame implements ActionListener{

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	static final int RETURN=1,LOAD=2,CLEAR=3,ALLCLEAR=4,CLOSE=-1;
	int message=10;
	Button returnback,load,clear,allclear;
	JTextArea jta;
	JLabel jl1;
	JPanel jp00,jp0;
	MyDialog()
	{
		
		jp00 = new JPanel();
		jp0 = new JPanel();	
		
		jta = new JTextArea(4,21);	
//		jta.setText("由于在文本框中直接输入的是表达式，\n所以统计框在这里失去其存在的意义");
		jta.append("由于在文本框中直接输入的是表达式，\n所以统计框在这里失去其存在的意义。\n这里只是形式上的存在~！");
		returnback = new Button("返回(R)");
		load = new Button("加载(L)");
		clear = new Button("清零(C)");
		allclear = new Button("全清(A)");
		jl1 = new JLabel("n=0");
		
		jp00.add(jta);	
		jp0.add(returnback);
		jp0.add(load);
		jp0.add(clear);
		jp0.add(allclear);
		returnback.addActionListener(this);
		load.addActionListener(this);
		clear.addActionListener(this);
		allclear.addActionListener(this);
		this.addWindowListener(new WindowAdapter()
		                  {
			                public void windowClosing(WindowEvent e)
			                {
			                	message=CLOSE;
			                	setVisible(false);
			                }
		                  });
		this.setLayout(new FlowLayout());		
		this.setFont(new Font("宋体",Font.PLAIN,12));
		this.setTitle("统计框");
		this.add(jp00);
		this.add(jp0);
		this.add(jl1);
		this.setVisible(false);
		this.setResizable(false);
		
	}
	public void actionPerformed(ActionEvent arg0) {
		// TODO Auto-generated method stub
		if(arg0.getSource()==returnback)
		{
			message=RETURN;
		}
		if(arg0.getSource()==load)
		{
			message=LOAD;
		}
		if(arg0.getSource()==clear)
		{
			message=CLEAR;
		}
		if(arg0.getSource()==allclear)
		{
			message=ALLCLEAR;
		}
	}
	public int getMessage()
	{
		return message;
	}
	
}
//----------------------------内部类-进制转换类--------------------
class objConversion
{//本进制类参考了CSMD类转换例子

//public void objConversion ()
//{
//}

public String decDec (int decNum)
{//10
  
   String strDecNum = Integer.toString(decNum);
  
   for (int i = strDecNum.length(); i < 3; i++)
   {
    strDecNum = "0" + strDecNum;
   }
  
// return strDecNum;
   return invert (strDecNum, 5);
  
}

public String decHex (int decNum)
{//10 to 16
  
   String strHexNum = "";
   int currentNum = 0;
  
   while (decNum != 0)
   {
   
    if (decNum > 15)
    {
    
     currentNum = decNum % 16;
     decNum /= 16;
    
    }
    else
    {
    
     currentNum = decNum;
     decNum = 0;
    
    }
   
    switch (currentNum)
    {
    
     case 15: strHexNum += "F";
        break;
     case 14: strHexNum += "E";
        break;
     case 13: strHexNum += "D";
        break;
     case 12: strHexNum += "C";
        break;
     case 11: strHexNum += "B";
        break;
     case 10: strHexNum += "A";
        break;
     default: strHexNum += Integer.toString(currentNum);
        break;
       
    }
   
   }
   
   return invert (strHexNum, 2);
   
}
  
public String decOct (int decNum)
{//10 to 8
  
   String strOctNum = "";
  
   while (decNum != 0)
   {
   
    if (decNum > 7)
    {
    
     strOctNum += Integer.toString(decNum % 8);
     decNum /= 8;
    
    }
    else
    {
    
     strOctNum += Integer.toString(decNum);
     decNum = 0;
    
    }
   
   }
  
   return invert (strOctNum, 3);
  
}

public String decBin (int decNum)
{//10 to 2
  
   String strBinNum = "";
  
   while (decNum != 0)
   {
   
    if (decNum > 1)
    {
    
     strBinNum += Integer.toString(decNum % 2);
     decNum /= 2;
    
    }
    else
    {
    
     strBinNum += Integer.toString(decNum);
     decNum = 0;
    
    }
   
   }
  
   return invert (strBinNum, 8);
  
}

private String invert (String strNum, int minLength) //转换长度
{  
  
   String answer = "";
   int length = strNum.length();
  
   if (length < minLength)
   {
   
    for (int padding = (minLength - length); padding > 0; padding--)
    {
     answer += "0";
    }
   
   }
  
   for (int i = length; i > 0; i--)
   {
    answer += strNum.charAt (i - 1);
   }
  
   return answer;
  
}
}

///---------------------------------------最关键的一个内部类----字符串转表达式并进行计算---------------------------------------------------------------

/*一、表达式的组成
1、数字
2、运算符：+ - / * ^ % =
3、圆括号
4、变量
二、运算符优先级
由高到低分别为：+-(正负号)、^、%、+-、=
优先级相等的运算符按照从左到右的顺序计算
三、关键技术点
1、确定运算的优先级，从高到低分别为：原子元素表达式，包括数字和变量；括号表达式；一元表达式，取数的负数；指数表达式；乘、除、取模表达式；加、减表达式；赋值表达式。
2、对于每一级别的运算，都由一个方法实现，在方法中先完成比自己高一级别的运算，再处理本级别的运算。因此，在计算整个表达式的主方法中，只需要调用最低级别的运算的实现方法即可。
3、确定表达式中的分隔符，（+、-、*、/、%、^、=、(、)、）。利用这些分隔符将表达式分成多段，每一段叫做一个token，分隔符也算token。
4、用长度为26的int数组vars存储变量的值。
5、Character的isWhitespace方法判断字符是否为空白符，用于去掉表达式中的空白符。
6、Character的isLetter方法判断字符是否为字母，用于提取表达式中的变量
7、Character的isDigit方法判断字符是否为数字，用于获取表达式中的数字
*/

public class Shiyan4 {
//	4种标记类型
	public static final int NONE_TOKEN = 0;    //标记为空或者结束符
	public static final int DELIMITER_TOKEN = 1;    //标记为分隔符
	public static final int VARIABLE_TOKEN = 2;    //标记为变量
	public static final int NUMBER_TOKEN = 3;    //标记为数字

//	4种错误类型
	public static final int SYNTAX_ERROR = 0;    //语法错误
	public static final int UNBALPARENS_ERROR = 1;    //括号没有结束错误
	public static final int NOEXP_ERROR = 2;    //表达式为空错误
	public static final int DIVBYZERO_ERROR = 3;    //被0除错误
//	private static  final double PI = 3.1415926535897932384626433832795;//给pi赋值

//	针对4种错误类型定义的4个错误提示

		public  final String[] ERROR_MESSAGES ={"Syntax Error", "Unbalanced ", "No Expression Present", "Division by Zero"};
	
	

//	表达式的结束标记
	public static final String EOE = "\0";

private String exp; //表达式字符串
private int expIndex; //解析器当前指针在表达式中的位置
private String token; //解析器当前处理的标记
private int tokenType; //解析器当前处理的标记类型
private double[] vars = new double[26]; //变量数组

/**
* 
*/
public Shiyan4() {
}


/**
* 判断一个字符是否为分隔符
* 表达式中的字符包括：
* 加“＋”、减“－”、乘“*”、除“/”、取模“%”、指数“^”、赋值“＝”、左括号“（”、右括号“）”......