youseries
6 år sedan
3 ändrade filer med 203 tillägg och 223 borttagningar
@ -1,220 +0,0 @@ |
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/******************************************************************************* |
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* Copyright 2017 Bstek |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); you may not |
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* use this file except in compliance with the License. You may obtain a copy |
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* of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
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* License for the specific language governing permissions and limitations under |
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* the License. |
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******************************************************************************/ |
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package com.bstek.ureport.utils; |
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import java.util.Collections; |
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import java.util.Stack; |
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/** |
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* @author Jacky.gao |
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* @since 2017年4月25日 |
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*/ |
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public class ElCalculator { |
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private static int[] PRIORITY = new int[] { 0, 3, 2, 1, -1, 1, 0, 2 };// 运用运算符ASCII码-40做索引的运算符优先级
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public void main(String[] args) { |
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try{ |
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String expr="'gaojie:'+5%26"; |
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System.out.println(eval(expr)); |
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}catch(Exception ex){ |
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System.out.println("="+ex.getMessage()+"="); |
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} |
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} |
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public Object eval(String expression) { |
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expression = transform(expression); |
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Object result = calculate(expression); |
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return result; |
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} |
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/** |
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* 将表达式中负数的符号更改 |
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* @param expression 例如-2+-1*(-3E-2)-(-1) 被转为 ~2+~1*(~3E~2)-(~1) |
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* @return 返回转换结果 |
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*/ |
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private String transform(String expression) { |
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char[] arr = expression.toCharArray(); |
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for (int i = 0; i < arr.length; i++) { |
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char cc=arr[i]; |
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if (cc == '-') { |
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if (i == 0) { |
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arr[i] = '~'; |
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} else { |
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char c = arr[i - 1]; |
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if (c == '+' || c == '-' || c == '*' || c == '/' || c == '(' || c == 'E' || c == 'e') { |
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arr[i] = '~'; |
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} |
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} |
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} |
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} |
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if(arr[0]=='~'||arr[1]=='('){ |
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arr[0]='-'; |
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return "0"+new String(arr); |
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}else{ |
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return new String(arr); |
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} |
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} |
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/** |
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* 按照给定的表达式计算 |
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* @param expression 要计算的表达式例如:5+12*(3+5)/7 |
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* @return 返回计算结果 |
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*/ |
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private Object calculate(String expression) { |
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Stack<String> postfixStack = new Stack<String>(); |
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Stack<Object> resultStack = new Stack<Object>(); |
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prepare(expression,postfixStack); |
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Collections.reverse(postfixStack);// 将后缀式栈反转
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while (!postfixStack.isEmpty()) { |
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String currentValue = postfixStack.pop(); |
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if (currentValue.equals("") || !isOperator(currentValue.charAt(0))) {// 如果不是运算符则存入操作数栈中
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if(currentValue.startsWith("\"")){ |
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currentValue=currentValue.substring(1,currentValue.length()-1); |
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} |
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currentValue = currentValue.replace("~", "-"); |
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resultStack.push(currentValue); |
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} else {// 如果是运算符则从操作数栈中取两个值和该数值一起参与运算
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String secondValue = resultStack.pop().toString(); |
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String firstValue = resultStack.pop().toString(); |
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// 将负数标记符改为负号
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firstValue = firstValue.replace("~", "-"); |
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secondValue = secondValue.replace("~", "-"); |
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Object tempResult = calculate(firstValue, secondValue, currentValue.charAt(0)); |
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resultStack.push(tempResult); |
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} |
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} |
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return resultStack.pop(); |
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} |
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private void prepare(String expression,Stack<String> postfixStack) { |
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Stack<Character> opStack = new Stack<Character>(); |
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opStack.push(',');// 运算符放入栈底元素逗号,此符号优先级最低
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char[] arr = expression.toCharArray(); |
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int currentIndex = 0;// 当前字符的位置
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int count = 0;// 上次算术运算符到本次算术运算符的字符的长度便于或者之间的数值
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char currentOp, peekOp;// 当前操作符和栈顶操作符
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String prevData=null; |
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for (int i = 0; i < arr.length; i++) { |
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currentOp = arr[i]; |
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if(isInvertedComma(currentOp)){ |
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currentIndex=i+1; |
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i++; |
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count=1; |
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while(i<arr.length){ |
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currentOp = arr[i]; |
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if(isInvertedComma(currentOp)){ |
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prevData=new String(arr, currentIndex, count-1); |
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prevData="\""+prevData+"\""; |
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break; |
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} |
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i++; |
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count++; |
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} |
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continue; |
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}else if(isOperator(currentOp)) { |
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//当前字符是运算符
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if(prevData!=null){ |
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postfixStack.push(prevData); |
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prevData=null; |
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}else if (count > 0) { |
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String data=new String(arr, currentIndex, count).trim(); |
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postfixStack.push(data); |
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//取两个运算符之间的内容
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} |
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peekOp = opStack.peek(); |
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if (currentOp == ')') { |
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//遇到反括号则将运算符栈中的元素移除到后缀式栈中直到遇到左括号
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while (opStack.peek() != '(') { |
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postfixStack.push(String.valueOf(opStack.pop())); |
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} |
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opStack.pop(); |
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} else { |
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while (currentOp != '(' && peekOp != ',' && compare(currentOp, peekOp)) { |
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postfixStack.push(String.valueOf(opStack.pop())); |
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peekOp = opStack.peek(); |
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} |
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opStack.push(currentOp); |
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} |
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count = 0; |
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currentIndex = i + 1; |
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} else { |
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count++; |
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} |
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} |
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if(prevData!=null){ |
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postfixStack.push(prevData); |
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}else if (count > 1 || (count == 1 && !isOperator(arr[currentIndex]))) {// 最后一个字符不是括号或者其他运算符的则加入后缀式栈中
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postfixStack.push(new String(arr, currentIndex, count)); |
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} |
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while (opStack.peek() != ',') { |
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postfixStack.push(String.valueOf(opStack.pop()));// 将操作符栈中的剩余的元素添加到后缀式栈中
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} |
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} |
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private boolean isInvertedComma(char c){ |
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return c=='"'; |
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} |
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private boolean isOperator(char c) { |
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return c == '+' || c == '-' || c == '*' || c == '/' || c == '%' || c == '(' || c == ')'; |
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} |
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public boolean compare(char cur, char peek) {// 如果是peek优先级高于cur,返回true,默认都是peek优先级要低
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if(cur=='%')cur='*'; |
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if(peek=='%')peek='*'; |
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boolean result = false; |
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if (PRIORITY[(peek) - 40] >= PRIORITY[(cur) - 40]) { |
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result = true; |
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} |
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return result; |
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} |
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private Object calculate(String firstValue, String secondValue, char currentOp) { |
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Object result = null; |
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try{ |
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switch (currentOp) { |
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case '+': |
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result = ArithUtils.add(firstValue, secondValue); |
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break; |
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case '-': |
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result = ArithUtils.sub(firstValue, secondValue); |
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break; |
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case '*': |
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result = ArithUtils.mul(firstValue, secondValue); |
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break; |
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case '/': |
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result = ArithUtils.div(firstValue, secondValue); |
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break; |
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case '%': |
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result = ArithUtils.com(firstValue, secondValue); |
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} |
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}catch(Exception ex){ |
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String msg=ex.getMessage() == null ? "" : ex.getMessage(); |
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String a=(firstValue == null ? "null" : firstValue.toString()); |
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String b=(secondValue == null ? "null" : secondValue.toString()); |
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if(currentOp=='+'){ |
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result = a+b; |
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}else if(currentOp=='/' && msg.indexOf("by zero")!=-1){ |
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result = "Infinity"; |
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}else{ |
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throw ex; |
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} |
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} |
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return result; |
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} |
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} |
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@ -0,0 +1,201 @@ |
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/******************************************************************************* |
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* 本软件作品的著作权、商标权等知识产权属于上海锐道信息技术有限公司(http://www.bstek.com)所有,
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* 任何单位和个人未经上海锐道信息技术有限公司书面授权,不得以任何目的、任何方式复制、传播本软件作品的任何部分, |
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* 否则将视为侵权,上海锐道信息技术有限公司保留依法追究其法律责任的权利。 |
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******************************************************************************/ |
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package com.bstek.ureport.utils; |
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import java.math.BigDecimal; |
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import java.math.RoundingMode; |
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import java.util.Stack; |
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/******************************************************************************* |
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* Copyright 2017 Bstek |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); you may not |
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* use this file except in compliance with the License. You may obtain a copy |
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* of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
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* License for the specific language governing permissions and limitations under |
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* the License. |
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******************************************************************************/ |
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import com.bstek.ureport.Utils; |
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/** |
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* @author Jacky.gao |
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* @since 2018年6月28日 |
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*/ |
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public class ElCompute { |
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private Stack<Object> dataStack=new Stack<Object>(); |
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private Stack<Character> operateStack=new Stack<Character>(); |
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public static void main(String[] args) { |
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long start=System.currentTimeMillis(); |
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String expr="(2+20)*3-10+\"super man\""; |
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for(int i=0;i<1;i++) { |
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ElCompute el=new ElCompute(); |
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Object data=el.doCompute(expr); |
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System.out.println(data); |
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} |
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long end=System.currentTimeMillis(); |
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System.out.println(end-start); |
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} |
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public Object doCompute(String expr) { |
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init(expr); |
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return dataStack.pop(); |
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} |
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private void init(String expr){ |
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StringBuilder dataSb=new StringBuilder(); |
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char prevQuote='0'; |
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for(int i=0;i<expr.length();i++){ |
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char c=expr.charAt(i); |
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switch(c){ |
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case '+': |
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addDataStack(dataSb); |
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doCalculate(0); |
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operateStack.push(c); |
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break; |
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case '-': |
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doMinus(dataSb, prevQuote); |
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break; |
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case '*': |
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addDataStack(dataSb); |
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doCalculate(2); |
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operateStack.push(c); |
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break; |
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case '/': |
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addDataStack(dataSb); |
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doCalculate(2); |
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operateStack.push(c); |
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break; |
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case '%': |
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addDataStack(dataSb); |
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doCalculate(2); |
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operateStack.push(c); |
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break; |
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case '(': |
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operateStack.push(c); |
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break; |
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case ')': |
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addDataStack(dataSb); |
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doCalculate(1); |
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break; |
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case '"': |
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if(prevQuote=='"'){ |
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prevQuote='0'; |
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dataStack.push(dataSb.toString()); |
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dataSb.setLength(0); |
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}else{ |
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prevQuote='"'; |
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} |
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break; |
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case ' ': |
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if(prevQuote=='"') { |
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dataSb.append(c); |
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} |
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break; |
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default: |
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dataSb.append(c); |
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} |
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} |
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if(dataSb.length()>0){ |
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addDataStack(dataSb); |
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} |
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doCalculate(0); |
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} |
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private void doMinus(StringBuilder dataSb,char prevQuote){ |
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if(dataSb.length()==0){ |
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dataSb.append('-'); |
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}else{ |
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addDataStack(dataSb); |
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doCalculate(0); |
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operateStack.push('-'); |
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} |
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} |
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private void doCalculate(int current) { |
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if(operateStack.empty()){ |
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return; |
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} |
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char prevOp=operateStack.peek(); |
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if(prevOp=='('){ |
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return; |
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} |
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if(current==0 || current==1){ |
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char op=operateStack.pop(); |
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do{ |
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Object right=dataStack.pop(); |
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Object left=dataStack.pop(); |
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Object result=calculate(left, op, right); |
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dataStack.push(result); |
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if(operateStack.isEmpty()){ |
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break; |
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} |
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op=operateStack.pop(); |
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}while(op!='('); |
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}else if(current==2){ |
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while(prevOp=='*' || prevOp=='/' || prevOp=='%') { |
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Object right=dataStack.pop(); |
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Object left=dataStack.pop(); |
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char op=operateStack.pop(); |
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Object result=calculate(left, op, right); |
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dataStack.push(result); |
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if(operateStack.isEmpty()){ |
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break; |
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} |
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prevOp=operateStack.peek(); |
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if(prevOp=='('){ |
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break; |
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} |
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} |
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} |
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} |
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private Object calculate(Object left,char op,Object right){ |
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if((op=='*' || op=='/' || op=='%' || op=='-')){ |
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if(right instanceof String || left instanceof String){ |
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throw new RuntimeException(left + " and "+right+" can't do "+op+"!"); |
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|
} |
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BigDecimal b1=(BigDecimal)left; |
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BigDecimal b2=(BigDecimal)right; |
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if(op=='*'){ |
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return b1.multiply(b2); |
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}else if(op=='/'){ |
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return b1.divide(b2,10,RoundingMode.HALF_UP).stripTrailingZeros(); |
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}else if(op=='%'){ |
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return b1.divideAndRemainder(b2)[1]; |
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}else if(op=='-'){ |
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return b1.subtract(b2); |
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} |
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}else if(op=='+'){ |
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if(right instanceof String || left instanceof String){ |
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return left.toString()+right.toString(); |
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}else{ |
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BigDecimal b1=(BigDecimal)left; |
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BigDecimal b2=(BigDecimal)right; |
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return b1.add(b2); |
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} |
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} |
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throw new RuntimeException("Unkown operate "+op+""); |
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} |
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|
private void addDataStack(StringBuilder dataSb) { |
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if(dataSb.length()==0)return; |
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String data=dataSb.toString(); |
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dataSb.setLength(0); |
||||
|
try{ |
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BigDecimal bd=Utils.toBigDecimal(data); |
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dataStack.push(bd); |
||||
|
}catch(Exception ex){ |
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|
dataStack.push(data); |
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|
} |
||||
|
} |
||||
|
} |
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