| /* |
| * 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.pig.builtin; |
| |
| import java.io.IOException; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.data.*; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| import org.apache.pig.impl.util.*; |
| |
| /** |
| * Search and find all matched characters in a string with a given |
| * regular expression. |
| * |
| * Example: |
| * |
| * a = LOAD 'mydata' AS (name:chararray); |
| * b = FOREACH A GENERATE REGEX_SEARCH(name, 'regEx'); |
| * |
| * input tuple: the first field is a string on which performs regular expression matching; |
| * the second field is the regular expression; |
| */ |
| |
| public class REGEX_SEARCH extends EvalFunc<DataBag> { |
| private static BagFactory bagFactory = BagFactory.getInstance(); |
| private static TupleFactory tupleFactory = TupleFactory.getInstance(); |
| |
| public REGEX_SEARCH() {} |
| |
| @Override |
| public DataBag exec(Tuple input) throws IOException { |
| |
| if (input == null || input.size() < 1) { |
| return null; |
| } |
| if (input.get(0)==null) |
| return null; |
| |
| try { |
| if (!input.get(1).equals(mExpression)) { |
| try { |
| mExpression = (String)input.get(1); |
| mPattern = Pattern.compile(mExpression); |
| } catch (Exception e) { |
| String msg = "StringSearchAll : Mal-Formed Regular expression : "+input.get(1); |
| throw new IOException(msg); |
| } |
| } |
| } catch (NullPointerException e) { |
| String msg = "StringSearchAll : Regular expression is null"; |
| throw new IOException(msg); |
| } |
| Matcher m = mPattern.matcher((String)input.get(0)); |
| if (!m.find()) { |
| return null; |
| } |
| |
| Tuple tuple0 = tupleFactory.newTuple(1); |
| tuple0.set(0, m.group(1)); |
| DataBag dataBag = bagFactory.newDefaultBag(); |
| dataBag.add(tuple0); |
| while (m.find()) { |
| Tuple tuple = tupleFactory.newTuple(1); |
| tuple.set(0, m.group(1)); |
| dataBag.add(tuple); |
| } |
| return dataBag; |
| } |
| |
| String mExpression = null; |
| Pattern mPattern = null; |
| @Override |
| public Schema outputSchema(Schema input) { |
| try { |
| return new Schema(Utils.getSchemaFromString("{(match:chararray)}")); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| @Override |
| public boolean allowCompileTimeCalculation() { |
| return true; |
| } |
| |
| } |