| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.nutch.util; |
| |
| import java.lang.invoke.MethodHandles; |
| import java.util.Date; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| import org.apache.commons.jexl2.Expression; |
| import org.apache.commons.jexl2.JexlEngine; |
| import org.apache.commons.lang.time.DateUtils; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Utility methods for handling JEXL expressions |
| */ |
| public class JexlUtil { |
| |
| private static final Logger LOG = LoggerFactory |
| .getLogger(MethodHandles.lookup().lookupClass()); |
| |
| /** Supported format for date parsing yyyy-MM-ddTHH:mm:ssZ */ |
| private static final Pattern DATE_PATTERN = Pattern.compile("\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z"); |
| |
| /** |
| * Parses the given expression to a JEXL expression. This supports |
| * date parsing. |
| * |
| * @param expr string JEXL expression |
| * @return parsed JEXL expression or null in case of parse error |
| */ |
| public static Expression parseExpression(String expr) { |
| if (expr == null) return null; |
| |
| try { |
| // Translate any date object into a long. Dates must be in the DATE_PATTERN |
| // format. For example: 2016-03-20T00:00:00Z |
| Matcher matcher = DATE_PATTERN.matcher(expr); |
| |
| if (matcher.find()) { |
| String date = matcher.group(); |
| |
| // parse the matched substring and get the epoch |
| Date parsedDate = DateUtils.parseDateStrictly(date, new String[] {"yyyy-MM-dd'T'HH:mm:ss'Z'"}); |
| long time = parsedDate.getTime(); |
| |
| // replace the original string date with the numeric value |
| expr = expr.replace(date, Long.toString(time)); |
| } |
| |
| JexlEngine jexl = new JexlEngine(); |
| |
| jexl.setSilent(true); |
| jexl.setStrict(true); |
| |
| return jexl.createExpression(expr); |
| } catch (Exception e) { |
| LOG.error(e.getMessage()); |
| } |
| |
| return null; |
| } |
| } |