文本计算器

Java真方便，还有自己的堆栈的定义，不用自己写了，那个输入一串数字就可以计算出结果的计算器我是没看懂（也懒的看，不喜欢看别人的东西，毛病，得改），自己就看着堆栈的定义，写了一个文本计算器，不知道还有没有毛病，有一个不会改的毛病就是没法提示错误，输入不正确的时候怎么让它提示啊？用try和catch不管用，郁闷，下面是源码：

import java.awt.*;import javax.swing.*;import java.awt.event.*;import java.io.*;import java.util.*;public class TxtCalculator implements ActionListener{JFrame f;JPanel pTxt = new JPanel();JTextField txt;JPanel pShow = new JPanel();JTextArea show;JMenu mEdit;JMenu mView;JMenu mHelp;JMenuItem mSave;JMenuItem mClear;JMenuItem mHelpItem;JMenuItem mAbout;JButton start;String strAll[][]=new String[100][100];public TxtCalculator(){f = new JFrame("文本计算器");JMenuBar mBar = new JMenuBar();mBar.setOpaque(true);mEdit = new JMenu("编辑");mSave = new JMenuItem("保存历史");mSave.addActionListener(this);mEdit.add(mSave);mClear = new JMenuItem("清空历史");mClear.addActionListener(this);mEdit.add(mClear);mHelp = new JMenu("帮助");mHelpItem = new JMenuItem("帮助主题");mHelpItem.addActionListener(this);mHelp.add(mHelpItem);mAbout = new JMenuItem("关于计算器");mAbout.addActionListener(this);mHelp.add(mAbout);mBar.add(mEdit);mBar.add(mHelp);f.setJMenuBar(mBar);txt = new JTextField();pTxt.setLayout(new BorderLayout());pShow.setLayout(new BorderLayout());start = new JButton("开始计算");start.setForeground(Color.blue);txt.addKeyListener(new KeyListener(){public void keyPressed(KeyEvent e){int keyCode = e.getKeyCode();if (keyCode == KeyEvent.VK_ENTER){System.out.println("用户按下了回车键");start.doClick();}}public void keyReleased(KeyEvent args) {}public void keyTyped(KeyEvent args) {}});start.addActionListener(this);show = new JTextArea("");show.setLineWrap(true);show.setEditable(false);txt.requestFocus();pTxt.add(txt,BorderLayout.CENTER);pTxt.add(new JScrollPane(start),BorderLayout.EAST);pShow.add(pTxt,BorderLayout.NORTH);JScrollPane show2=new JScrollPane(show);pShow.add(show2,BorderLayout.CENTER);f.add(pShow);f.setSize(new Dimension(300,270));f.setResizable(false);f.setVisible(true);f.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.out.println("用户已经成功关闭软件！");System.exit(0);}});}public void actionPerformed(ActionEvent e){String s = e.getActionCommand();if(s.equals("保存历史")){System.out.println("用户按下了“保存历史”菜单");try{FileWriter txtWriter=new FileWriter("History.txt");BufferedWriter writer=new BufferedWriter(txtWriter);String S=show.getText();S="/*文本计算器*/\r\n/*制作人：曹晨曦*/\r\n/*欢迎交流使用！*/\r\n/*E-mail:[e-mail]*/\r\n/*这是文本计算器的保存文件，可以根据您的需要在这里面保存记录*/\r\n"+S;writer.write(S);writer.close();System.out.println("历史History.txt已经保存到CLASS文件根目录！");JOptionPane.showMessageDialog(null,"历史History.txt已经保存到CLASS文件根目录！","提示",JOptionPane.WARNING_MESSAGE);Runtime.getRuntime().exec("cmd /c start .\\");}catch(IOException ee){}   }   else if(s.equals("清空历史"))   {   System.out.println("用户按下了“清空历史”菜单");   show.setText("");   }   else if(s.equals("帮助主题")){System.out.println("用户按下了“帮助主题”菜单");JOptionPane.showMessageDialog(null,"输入表达式即可,只支持有理数和括号\"(\",\")\"","帮助主题",JOptionPane.WARNING_MESSAGE);}else if(s.equals("关于计算器")){System.out.println("用户按下了“关于计算器”菜单");JOptionPane.showMessageDialog(null,"由曹晨曦制作，欢迎使用","关于计算器",JOptionPane.WARNING_MESSAGE);}   else if(s.equals("开始计算"))   {   System.out.println("用户按下了“开始计算”按钮");   String exp=txt.getText().trim();   int strLength[]=new int[1000];   for(int i=0;i<100;i++){for(int j=0;j<100;j++){strAll[i][j]=null;}}String expBr;expBr=SeparateAllString("#"+exp+"#",strLength);SeparateString("#"+expBr+"#",strAll[99]);for(int k=0;k<100;k++){if(strAll[99][k]==null){strLength[99]=k;break;}}txt.setText(""); if(exp.compareTo("")!=0){String stemp;stemp=doubleTrans(CalculatorAlgorithm(strAll[99],strLength[99]));if(stemp.compareTo("Infinity")==0){stemp="+∞";show.append(exp+"="+stemp+"\r\n");System.out.println(exp+"="+stemp);}else if(stemp.compareTo("-Infinity")==0){stemp="-∞";show.append(exp+"="+stemp+"\r\n");System.out.println(exp+"="+stemp);}else{show.append(exp+"="+stemp+"\r\n");System.out.println(exp+"="+stemp);}}txt.requestFocus();   }   }   String doubleTrans(double d){  if(Math.round(d)-d==0)  {return String.valueOf((long)d);}return String.valueOf(d);}double CalculatorAlgorithm(String str[],int strLength){if(strLength==3){double n;n=Double.parseDouble(str[1]);return n;}Stack stkNum=new Stack();Stack stkOp=new Stack();Stack stkNumTaken=new Stack();Stack stkOpTaken=new Stack();double operateNum1=0.0,operateNum2=0.0;int pOp=0,cOp=0;boolean LastFirst=false;String ptempOp,ctempOp;String FirstOp,EndOp;int pPriority=0,cPriority=0;for(int i=strLength-1;i>=0;i--){if(str[i].charAt(str[i].length()-1)>='0'&&str[i].charAt(str[i].length()-1)<='9'){double n;n=Double.parseDouble(str[i]);stkNum.push(n);}else stkOp.push(str[i]+"");}FirstOp=(String)stkOp.pop();while(!stkOp.empty()){if(!stkOpTaken.empty()&&!LastFirst){operateNum1=(Double)stkNumTaken.pop();ptempOp=(String)stkOpTaken.pop();}else{operateNum1=(Double)stkNum.pop();ptempOp=(String)stkOp.pop();}if(ptempOp.compareTo("+")==0){pPriority=20;pOp=1;}else if(ptempOp.compareTo("-")==0){pPriority=20;pOp=2;}else if(ptempOp.compareTo("*")==0){pPriority=50;pOp=3;}else if(ptempOp.compareTo("/")==0){pPriority=50;pOp=4;}else if(ptempOp.compareTo("#")==0){pPriority=1;pOp=0;}if(!stkOpTaken.empty()&&!LastFirst){operateNum2=(Double)stkNumTaken.pop();ctempOp=(String)stkOpTaken.pop();}else{operateNum2=(Double)stkNum.pop();ctempOp=(String)stkOp.pop();LastFirst=false;}if(ctempOp.compareTo("+")==0){cPriority=20;cOp=1;}else if(ctempOp.compareTo("-")==0){cPriority=20;cOp=2;}else if(ctempOp.compareTo("*")==0){cPriority=50;cOp=3;}else if(ctempOp.compareTo("/")==0){cPriority=50;cOp=4;}else if(ctempOp.compareTo("#")==0){cPriority=1;cOp=0;}if(pPriority>=cPriority){switch(pOp){case 1:operateNum2=operateNum1+operateNum2;break;case 2:operateNum2=operateNum1-operateNum2;break;case 3:operateNum2=operateNum1*operateNum2;break;case 4:operateNum2=operateNum1/operateNum2;break;}}else{stkNumTaken.push(operateNum1);stkOpTaken.push(ptempOp+"");LastFirst=true;}stkNum.push(operateNum2);stkOp.push(ctempOp+"");if(stkOpTaken.empty()&&ctempOp.compareTo("#")==0)break;}double m=0.0;m=(Double)stkNum.pop();return m;}void SeparateString(String s,String str[]){int i;int j;boolean bSNum;boolean bSOp;boolean bSLFunc;boolean bSRFunc;boolean bSBra;boolean bSNumF;boolean bSOpF;boolean bSLFuncF;boolean bSRFuncF;boolean bSBraF;boolean bSEnd;boolean bSEndF;str[0]=""+s.charAt(0);j=0;for(i=1;i<s.length();i++){bSEndF=(s.charAt(i-1)=='#');bSEnd=(s.charAt(i)=='#');bSNumF=(s.charAt(i-1)>='0'&&s.charAt(i-1)<='9')||(s.charAt(i-1)=='.')||(s.charAt(i-1)=='-');bSNum=(s.charAt(i)>='0'&&s.charAt(i)<='9')||(s.charAt(i)=='.')||(s.charAt(i)=='-');bSOpF=((s.charAt(i-1)=='+')||(s.charAt(i-1)=='*')||(s.charAt(i-1)=='/'));bSOp=((s.charAt(i)=='+')||(s.charAt(i)=='*')||(s.charAt(i)=='/'));bSLFuncF=(s.charAt(i-1)>='a'&&s.charAt(i-1)<='z');bSLFunc=(s.charAt(i)>='a'&&s.charAt(i)<='z');bSRFuncF=((s.charAt(i-1)=='!'));bSRFunc=((s.charAt(i)=='!'));bSBraF=((s.charAt(i-1)=='(')||(s.charAt(i-1)==')'));bSBra=((s.charAt(i)=='(')||(s.charAt(i)==')'));if(bSNumF&&bSNum){if((s.charAt(i-1)>='0'&&s.charAt(i-1)<='9'||(s.charAt(i-1)=='.')||(s.charAt(i-1)=='-'))&&s.charAt(i)=='-'&&(s.charAt(i+1)>='0'&&s.charAt(i+1)<='9'||(s.charAt(i+1)=='.')||(s.charAt(i+1)=='-')))j++;if((s.charAt(i-2)>='0'&&s.charAt(i-2)<='9')&&s.charAt(i-1)=='-'&&(s.charAt(i)>='0'&&s.charAt(i)<='9'))j++;}else if(bSOpF&&bSOp){}else if(bSLFuncF&&bSLFunc){}else if(bSRFuncF&&bSRFunc){}else if(bSBraF&&bSBra){}else if(bSEndF&&bSEnd){}else j++;if(str[j]!=null)str[j]=str[j]+s.charAt(i);else str[j]=""+s.charAt(i);}}String SeparateAllString(String s,int strLength[]){String str[]=new String[1000];Stack stkString=new Stack();Stack stkStringTaken=new Stack();int i=1;int count=1;while(s.charAt(i)!='#'){stkString.push(s.charAt(i));i++;}i=0;while(count!=0){count=0;while(!stkString.empty()){char temp;temp=(Character)stkString.pop();stkStringTaken.push(temp);if(temp==')')count++;if(temp=='('){count--;stkStringTaken.pop();while((Character)stkStringTaken.peek()!=')'){if(str[i]!=null)str[i]=str[i]+(Character)stkStringTaken.pop();else str[i]=""+(Character)stkStringTaken.pop();}stkStringTaken.pop();SeparateString("#"+str[i]+"#",strAll[i]);for(int j=0;j<100;j++){if(strAll[i][j]==null){strLength[i]=j;break;}}String swap;swap=""+CalculatorAlgorithm(strAll[i],strLength[i]);for(int iii=swap.length()-1;iii>=0;iii--)stkStringTaken.push(swap.charAt(iii));i++;}}while(!stkString.empty())stkString.pop();while(!stkStringTaken.empty()){char swap;swap=(Character)stkStringTaken.pop();if(swap=='('&&swap==')')count++;stkString.push(swap);}}s="";while(!stkString.empty())s=(Character)stkString.pop()+s;return s;}public static void main(String[] args){new TxtCalculator();}}