Java实现带图形界面的表达式计算器

package org.hq.calculator; import java.math.BigDecimal; import java.util.Scanner; public class Calculator { public static final String errorInfo = "Error"; public static final String infinityInfo = "Infinity"; public static final String naNInf = "NaN"; public static final double maxNum = 1.5E16; // Factorial public static String factorial(int n) { double resDou = 1; if (n > 170) { return infinityInfo; } else { for (int i = 1; i <= n; i++) { resDou *= i; if (resDou > Double.MAX_VALUE) return infinityInfo; } return Double.toString(resDou); } } // 以10为低 public static String log(double num) { double resDou = Math.log(num) / Math.log(10); if( resDou > maxNum){ return infinityInfo; } return String.valueOf(resDou); } // ln指数计算 public static String ln(double num) { double resDou = Math.log(num); if( resDou > maxNum){ return infinityInfo; } return String.valueOf(resDou); } // sin: 1，按照弧度计算，2：按照度数计算 public static String sin(int type, double num) { if (1 == type) { double resDou = Math.sin(num); if( resDou > maxNum){ return infinityInfo; } return String.valueOf(resDou); } else if (2 == type) { double radian = num*Math.PI/180; double resDou = Math.sin(radian); if( resDou > maxNum){ return infinityInfo; } return String.valueOf(resDou); } else { LogInfo.printError("Wrong Type in Sin:" + num); return ""; } } // cos public static String cos(int type, double num) { if (1 == type) { double resDou = Math.cos(num); if( resDou > maxNum){ return infinityInfo; } return String.valueOf(resDou); } else if (2 == type) { double radian = num * Math.PI / 180;// 角度转化为弧度 double resDou = Math.cos(radian); if( resDou > maxNum){ return infinityInfo; } return String.valueOf(resDou); } else { LogInfo.printError("Wrong Type in Sin:" + type); return ""; } } // tan public static String tan(int type, double num) { if (1 == type) { double resDou = Math.tan(num); if( resDou > maxNum){ return infinityInfo; } return String.valueOf(resDou); } else if (2 == type) { double radian = num * Math.PI / 180;// 角度转化为弧度 double resDou = Math.tan(radian); if( resDou > maxNum){ return infinityInfo; } return String.valueOf(resDou); } else { LogInfo.printError("Wrong Type in Sin:" + type); return ""; } } // exp public static String exp(double num) { double resDou = Math.exp(num); if( resDou > maxNum){ return infinityInfo; } return String.valueOf(resDou); } public boolean isOperator(char _operator) { return ('+' == _operator || '-' == _operator || '*' == _operator || '/' == _operator || '^' == _operator || '(' == _operator || ')' == _operator); } // 判断一个字符串是否为数字 public boolean isNumStr(String _numberStr) { return !("+".equals(_numberStr) || "^".equals(_numberStr) || "-".equals(_numberStr) || "*".equals(_numberStr) || "/".equals(_numberStr) || ")".equals(_numberStr) || "(".equals(_numberStr) || "=".equals(_numberStr)); } // 判断一个字符串是否为运算符 public boolean isOperatorStr(String _operatorStr) { return ("+".equals(_operatorStr) || "^".equals(_operatorStr) || "-".equals(_operatorStr) || "*".equals(_operatorStr) || "/" .equals(_operatorStr)); } public boolean isnumber(char ch) { return (ch >= '0' && ch <= '9'); } // 比较运算符的优先级，返回值含义： // 1: 优先级高于 0:优先级低于 -1:错误的运算符 2:优先级相同 public int compareCaculatorOperator(String _caculatorOperator1, String _caculatorOperator2) { if ("^".equals(_caculatorOperator1)) { if ("^".equals(_caculatorOperator2)) { return 2; } else if ("*".equals(_caculatorOperator2) || "/".equals(_caculatorOperator2) || "+".equals(_caculatorOperator2) || "-".equals(_caculatorOperator2)) { return 1; } else { return -1; } } else if ("*".equals(_caculatorOperator1) || "/".equals(_caculatorOperator1)) { if ("^".equals(_caculatorOperator2)) { return 0; } else if ("*".equals(_caculatorOperator2) || "/".equals(_caculatorOperator2)) { return 2; } else if ("+".equals(_caculatorOperator2) || "-".equals(_caculatorOperator2)) { return 1; } else { return -1; } } else if ("+".equals(_caculatorOperator1) || "-".equals(_caculatorOperator1)) { if ("^".equals(_caculatorOperator2) || "*".equals(_caculatorOperator2) || "/".equals(_caculatorOperator2)) { return 0; } else if ("+".equals(_caculatorOperator2) || "-".equals(_caculatorOperator2)) { return 2; } else { return -1; } } else { return -1; } } // 将一个表达式转化为栈结构 public ExStack getInfxStackfromStr(String infx) { // 新建一个栈存储表达式 ExStack myStack = new ExStack(); // 做一个标记(是否获得了一个数字) // 如果为假，将‘-’看做数字的一部分，为真，将‘-’看做运算符 boolean getANum = false; // 临时字符串 StringBuffer temStr = new StringBuffer(); char temChar = ' '; // 如果表达式以'-('开头，自动插入0 if (infx.length() > 2 && '-' == infx.charAt(0) && '(' == infx.charAt(1)) { myStack.push("0"); } for (int i = 0; i < infx.length(); i++) { temChar = infx.charAt(i); if ((!getANum && '-' == temChar) || !isOperator(temChar)) // 是数字 { temStr.append(temChar); getANum = true; } else { // 是一个操作符 if (!"".equals(temStr.toString())) { myStack.push(temStr.toString());// 压栈 temStr.delete(0, temStr.length()); // 清空temStr } myStack.push("" + temChar); // 压入运算符 if (')' != temChar) { getANum = false; } else { // ‘)’好后面的‘-’好应被看做运算符 getANum = true; } } } if (0 != temStr.length()) { myStack.push(temStr.toString()); } return myStack; } public ExStack infixToPosfix(ExStack infixStack) { String[] exps = infixStack.getDataArray(); ExStack myPosfixStack = new ExStack(); ExStack temStack = new ExStack(); boolean getNumber = false; boolean getOperator = false; for (int i = 0; i < infixStack.size(); i++) // 注意遍历区间控制!! { if (isNumStr(exps[i])) // 是数字，直接放入posfix序列中 { getOperator = false; if (getNumber) // 如果之前处理的也是数字，在它后面插入一个*号 { myPosfixStack.push(exps[i]); myPosfixStack.push("*"); } else { myPosfixStack.push(exps[i]); getNumber = true; } } else if ("(".equals(exps[i])) // 遇到开括号，压栈 { temStack.push(exps[i]); } else if (")".equals(exps[i])) // 遇到闭括号时 { if (temStack.isEmpty()) { LogInfo.printError("brackets not match！"); return null; } else { while (!"(".equals(temStack.top())) { myPosfixStack.push(temStack.top()); temStack.pop(); if (temStack.isEmpty()) { LogInfo.printError("brackets not match！"); return null; } } if ("(".equals(temStack.top())) { temStack.pop(); // 弹出开括号 } } } else if (isOperatorStr(exps[i])) // 为运算符 { getNumber = false; if (getOperator) // 连续两个运算符 { LogInfo.printError("Wrong Exps."); return null; } else { getOperator = true; } while (!temStack.isEmpty() && !"(".equals(temStack.top()) && compareCaculatorOperator(temStack.top(), exps[i]) > 0) { myPosfixStack.push(temStack.top()); temStack.pop(); } temStack.push(exps[i]); // 将输入运算符放入栈内 } } while (!temStack.isEmpty()) { if ("(".equals(temStack.top())) { LogInfo.printError("brackets not match！"); return null; } myPosfixStack.push(temStack.top()); t