diff options
Diffstat (limited to 'resource-assignment/provider/src/main/java/org/openecomp/sdnc/util/expr/ExpressionEvaluator.java')
| -rw-r--r-- | resource-assignment/provider/src/main/java/org/openecomp/sdnc/util/expr/ExpressionEvaluator.java | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/resource-assignment/provider/src/main/java/org/openecomp/sdnc/util/expr/ExpressionEvaluator.java b/resource-assignment/provider/src/main/java/org/openecomp/sdnc/util/expr/ExpressionEvaluator.java new file mode 100644 index 0000000..a6e8902 --- /dev/null +++ b/resource-assignment/provider/src/main/java/org/openecomp/sdnc/util/expr/ExpressionEvaluator.java @@ -0,0 +1,207 @@ +/*- + * ============LICENSE_START======================================================= + * openECOMP : SDN-C + * ================================================================================ + * Copyright (C) 2017 AT&T Intellectual Property. All rights + * reserved. + * ================================================================================ + * 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 + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * 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. + * ============LICENSE_END========================================================= + */ + +package org.openecomp.sdnc.util.expr; + +import java.util.Map; + +public class ExpressionEvaluator { + + public static long evalLong(String expr, Map<String, Object> vars) { + return (long) evalFloat(expr, vars); + } + + public static float evalFloat(String expr, Map<String, Object> vars) { + expr = expr.trim(); + int sl = expr.length(); + if (sl == 0) + throw new IllegalArgumentException("Cannot interpret empty string."); + + // Remove parentheses if any + if (expr.charAt(0) == '(' && expr.charAt(sl - 1) == ')') + return evalFloat(expr.substring(1, sl - 1), vars); + + // Look for operators in the order of least priority + String[] sss = findOperator(expr, "-", true); + if (sss != null) + return evalFloat(sss[0], vars) - evalFloat(sss[1], vars); + + sss = findOperator(expr, "+", true); + if (sss != null) + return evalFloat(sss[0], vars) + evalFloat(sss[1], vars); + + sss = findOperator(expr, "/", true); + if (sss != null) + return evalFloat(sss[0], vars) / evalFloat(sss[1], vars); + + sss = findOperator(expr, "*", true); + if (sss != null) + return evalFloat(sss[0], vars) * evalFloat(sss[1], vars); + + // Check if expr is a number + try { + return Float.valueOf(expr); + } catch (Exception e) { + } + + // Must be a variable + Object v = vars.get(expr); + if (v != null) { + if (v instanceof Float) + return (Float) v; + if (v instanceof Long) + return (Long) v; + if (v instanceof Integer) + return (Integer) v; + } + return 0; + } + + public static boolean evalBoolean(String expr, Map<String, Object> vars) { + expr = expr.trim(); + int sl = expr.length(); + if (sl == 0) + throw new IllegalArgumentException("Cannot interpret empty string."); + + if (expr.equalsIgnoreCase("true")) + return true; + + if (expr.equalsIgnoreCase("false")) + return false; + + // Remove parentheses if any + if (expr.charAt(0) == '(' && expr.charAt(sl - 1) == ')') + return evalBoolean(expr.substring(1, sl - 1), vars); + + // Look for operators in the order of least priority + String[] sss = findOperator(expr, "or", true); + if (sss != null) + return evalBoolean(sss[0], vars) || evalBoolean(sss[1], vars); + + sss = findOperator(expr, "and", true); + if (sss != null) + return evalBoolean(sss[0], vars) && evalBoolean(sss[1], vars); + + sss = findOperator(expr, "not", true); + if (sss != null) + return !evalBoolean(sss[1], vars); + + sss = findOperator(expr, "!=", false); + if (sss == null) + sss = findOperator(expr, "<>", false); + if (sss != null) + return evalLong(sss[0], vars) != evalLong(sss[1], vars); + + sss = findOperator(expr, "==", false); + if (sss == null) + sss = findOperator(expr, "=", false); + if (sss != null) + return evalLong(sss[0], vars) == evalLong(sss[1], vars); + + sss = findOperator(expr, ">=", false); + if (sss != null) + return evalLong(sss[0], vars) >= evalLong(sss[1], vars); + + sss = findOperator(expr, ">", false); + if (sss != null) + return evalLong(sss[0], vars) > evalLong(sss[1], vars); + + sss = findOperator(expr, "<=", false); + if (sss != null) + return evalLong(sss[0], vars) <= evalLong(sss[1], vars); + + sss = findOperator(expr, "<", false); + if (sss != null) + return evalLong(sss[0], vars) < evalLong(sss[1], vars); + + throw new IllegalArgumentException("Cannot interpret '" + expr + "': Invalid expression."); + } + + private static String[] findOperator(String s, String op, boolean delimiterRequired) { + int opl = op.length(); + int sl = s.length(); + String delimiters = " \0\t\r\n()"; + int pcount = 0, qcount = 0; + for (int i = 0; i < sl; i++) { + char c = s.charAt(i); + if (c == '(' && qcount == 0) + pcount++; + else if (c == ')' && qcount == 0) { + pcount--; + if (pcount < 0) + throw new IllegalArgumentException("Cannot interpret '" + s + "': Parentheses do not match."); + } else if (c == '\'') + qcount = (qcount + 1) % 2; + else if (i <= sl - opl && pcount == 0 && qcount == 0) { + String ss = s.substring(i, i + opl); + if (ss.equalsIgnoreCase(op)) { + boolean found = true; + if (delimiterRequired) { + // Check for delimiter before and after to make sure it is not part of another word + char chbefore = '\0'; + if (i > 0) + chbefore = s.charAt(i - 1); + char chafter = '\0'; + if (i < sl - opl) + chafter = s.charAt(i + opl); + found = delimiters.indexOf(chbefore) >= 0 && delimiters.indexOf(chafter) >= 0; + } + if (found) { + // We've found the operator, split the string + String[] sss = new String[2]; + sss[0] = s.substring(0, i); + sss[1] = s.substring(i + opl); + return sss; + } + } + } + } + if (pcount > 0) + throw new IllegalArgumentException("Cannot interpret '" + s + "': Parentheses do not match."); + if (qcount > 0) + throw new IllegalArgumentException("Cannot interpret '" + s + "': No closing '."); + return null; + } + + private static Object parseObject(String s) { + s = s.trim(); + int sl = s.length(); + if (sl == 0) + throw new IllegalArgumentException("Cannot interpret empty string."); + if (s.equalsIgnoreCase("null")) + return null; + if (s.charAt(0) == '\'') { + if (sl < 2 || s.charAt(sl - 1) != '\'') + throw new IllegalArgumentException("Cannot interpret '" + s + "': No closing '."); + return s.substring(1, sl - 1); + } + // Not in quotes - must be a number + try { + return Long.valueOf(s); + } catch (Exception e) { + } + try { + return Double.valueOf(s); + } catch (Exception e) { + throw new IllegalArgumentException("Cannot interpret '" + s + "': Invalid number."); + } + } +} |