Java tutorial
/** * Copyright (C) 2015 ZTE, Inc. and others. All rights reserved. (ZTE) * <p/> * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except * in compliance with the License. You may obtain a copy of the License at * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * Unless required by applicable law or agreed to in writing, software distributed under the License * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express * or implied. See the License for the specific language governing permissions and limitations under * the License. */ package com.zte.ums.zenap.itm.agent.plugin.linux.util; import com.zte.ums.zenap.itm.agent.common.util.AgentUtil; import org.apache.commons.jexl2.Expression; import org.apache.commons.jexl2.JexlContext; import org.apache.commons.jexl2.JexlEngine; import org.apache.commons.jexl2.MapContext; import java.math.RoundingMode; import java.text.DecimalFormat; import java.text.NumberFormat; import java.util.*; public class Calculator { public String calculateItem(Map variables, String formula) throws MonitorException { Set vKeySet = variables.keySet(); Object[] keys = vKeySet.toArray(); Arrays.sort(keys); JexlContext jexlContext = new MapContext(); for (int i = keys.length - 1; i >= 0; i--) { String s = keys[i].toString(); String s1 = s.replace('.', 'a'); formula = formula.replaceAll(s, s1); jexlContext.set(s1, variables.get(s)); } try { while (true) { int eIndex = formula.indexOf("E"); if (eIndex == -1) { break; } int startIndex = getBackwardNumIndex(formula, eIndex); int endIndex = getForwardNumIndex(formula, eIndex); String eNum = formula.substring(eIndex + 1, endIndex); String tenNumString = null; int num = Integer.parseInt(eNum); if (num > 5) { int tenNum = 1; for (int i = 0; i < (num - 5); i++) { tenNum = tenNum * 10; } tenNumString = "100000.0 * " + Integer.toString(tenNum); } else if (num > 0) { int tenNum = 1; for (int i = 0; i < num; i++) { tenNum = tenNum * 10; } tenNumString = Integer.toString(tenNum); } else if (num < 0) { double tenNum = 1; for (int i = 0; i > num; i--) { tenNum = tenNum * 0.1; } tenNumString = Double.toString(tenNum); } String variable = formula.substring(startIndex, endIndex); String headVariable = formula.substring(startIndex, eIndex); formula = formula.replaceFirst(variable, "(" + headVariable + " * " + tenNumString + ")"); } JexlEngine jexlEngine = new JexlEngine(); Expression expression = jexlEngine.createExpression(formula); Object result = expression.evaluate(jexlContext); if (result instanceof Double) { Double dd = (Double) result; NumberFormat formater = new DecimalFormat("#.00"); formater.setRoundingMode(RoundingMode.HALF_UP); return formater.format(dd); } return result.toString(); } catch (Exception e) { throw new MonitorException("Error!Something wrong happened! ", e); } } private int getForwardNumIndex(String formula, int eIndex) { int i; for (i = eIndex + 1; i < formula.length(); i++) { char charNum = formula.charAt(i); if ((charNum < '0' || charNum > '9') && (i != eIndex + 1)) { break; } } return i; } private int getBackwardNumIndex(String formula, int eIndex) { int i; for (i = eIndex - 1; i >= 0; i--) { char charNum = formula.charAt(i); if ((charNum < '0' || charNum > '9') && (charNum != '.')) { break; } else { if (i == 0) { return 0; } } } return (i + 1); } public List<String> calculate(Map<String, List<String>> listMap, String formula) throws MonitorException { while (true) { int index = formula.indexOf("SUM("); if (index == -1) { break; } int rightbrace = formula.indexOf(")", index); if (rightbrace == -1) { throw new MonitorException("Right braces doesn't appear to exist in SUM():" + formula); } String listName = formula.substring(index + 4, rightbrace); List<String> vec = listMap.get(listName); if (vec == null) { throw new MonitorException("List " + listName + " doesn't appear to exist in listMap."); } double sumResult = 0; for (String numString : vec) { double thisNum = Double.parseDouble(numString); sumResult = sumResult + thisNum; } String sumString = Double.toString(sumResult); String nameString = "SUM(" + listName + ")"; formula = AgentUtil.replace(formula, nameString, sumString); } while (true) { int index = formula.indexOf("COUNT("); if (index == -1) { break; } int rightbrace = formula.indexOf(")", index); if (rightbrace == -1) { throw new MonitorException("Right braces doesn't appear to exist in COUNT():" + formula); } String listName = formula.substring(index + 6, rightbrace); List<String> list = listMap.get(listName); if (list == null) { throw new MonitorException("List " + listName + " doesn't appear to exist in listMap."); } int count = list.size(); if (count == 0) { throw new MonitorException("List " + listName + "'s lenght is zero."); } String countString = Integer.toString(count); formula = AgentUtil.replace(formula, "COUNT(" + listName + ")", countString); } List<String> listVariables = new ArrayList<String>(); Set<String> keySet = listMap.keySet(); for (String listName : keySet) { if (formula.contains(listName)) { listVariables.add(listName); } } if (listVariables.size() == 0) { List<String> result = new ArrayList<String>(); result.add(calculateItem(new HashMap(), formula)); return result; } else { List<String> list = listMap.get(listVariables.get(0)); int longestSize = list.size(); if (longestSize == 0) { throw new MonitorException("List " + listVariables.get(0) + "'s size is 0"); } int longestIndex = 0; for (int i = 1, size = listVariables.size(); i < size; i++) { List<String> otherList = listMap.get(listVariables.get(i)); if (otherList.size() > longestSize) { longestSize = otherList.size(); longestIndex = i; } if (otherList.size() == 0) { throw new MonitorException("ArrayList " + listVariables.get(i) + "'s size is 0"); } } if (longestSize > 1) { for (int i = 0, size = listVariables.size(); i < size; i++) { if (i == longestIndex) { continue; } List<String> otherList = listMap.get(listVariables.get(i)); if (otherList.size() != longestSize && otherList.size() != 1) { throw new MonitorException("List " + listVariables.get(i) + "'s size is not " + longestSize + " and it is not 1"); } } } List<String> result = new ArrayList<String>(); for (int j = 0; j < longestSize; j++) { String newFormula = formula; for (String listVariable : listVariables) { List<String> thislist = listMap.get(listVariable); String thisListItem; if (thislist.size() > j) { thisListItem = String.valueOf(thislist.get(j)); } else { thisListItem = String.valueOf(thislist.get(0)); } newFormula = newFormula.replaceAll(String.valueOf(listVariable), thisListItem); } String resultItem; try { resultItem = calculateItem(new HashMap(), newFormula); } catch (MonitorException e) { throw new MonitorException( e.getMessage() + "(OldFormula=" + formula + " NewFormula=" + newFormula + ")", e); } result.add(resultItem); } return result; } } public List fcalculate(Map listMap, String formula, String[] variable) throws MonitorException { List retList = new ArrayList(); Object obj = null; try { JexlContext jexlContext = new MapContext(); JexlEngine jexlEngine = new JexlEngine(); Expression expression = jexlEngine.createExpression(formula); int sizej = ((List) (listMap.get(variable[0]))).size(); // List? for (int j = 0; j < sizej; j++) { // ??? for (int i = 0, sizei = variable.length; i < sizei; i++) { jexlContext.set(variable[i], ((List) (listMap.get(variable[i]))).get(j)); } obj = expression.evaluate(jexlContext); if (obj instanceof Double) { Double dd = (Double) obj; double dd1 = (dd.doubleValue() * 1000); long ld1 = (long) dd1; double dd2 = ld1 / 1000.0; String sResult = Double.toString(dd2); retList.add(sResult); } else { throw new MonitorException("formular's result is not double type" + formula); } } return retList; } catch (Exception e) { throw new MonitorException( "parsing expression, or expression neither an expression or a reference! or evaluate error" + e.getMessage()); } } }