~~~ /** * Copyright 2009-2018 the original author or authors. * * 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. */ package org.apache.ibatis.scripting.xmltags; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import ognl.Ognl; import ognl.OgnlException; import org.apache.ibatis.builder.BuilderException; /** * Caches OGNL parsed expressions. * * @author Eduardo Macarron * * @see <a href='http://code.google.com/p/mybatis/issues/detail?id=342'>Issue 342</a> */ public final class OgnlCache { private static final OgnlMemberAccess MEMBER_ACCESS = new OgnlMemberAccess(); private static final OgnlClassResolver CLASS_RESOLVER = new OgnlClassResolver(); private static final Map<String, Object> expressionCache = new ConcurrentHashMap<>(); private OgnlCache() { // Prevent Instantiation of Static Class } public static Object getValue(String expression, Object root) { try { Map context = Ognl.createDefaultContext(root, MEMBER_ACCESS, CLASS_RESOLVER, null); return Ognl.getValue(parseExpression(expression), context, root); } catch (OgnlException e) { throw new BuilderException("Error evaluating expression '" + expression + "'. Cause: " + e, e); } } private static Object parseExpression(String expression) throws OgnlException { Object node = expressionCache.get(expression); if (node == null) { node = Ognl.parseExpression(expression); expressionCache.put(expression, node); } return node; } } ~~~