001 /* 002 * Copyright (c) 2007-2014 Concurrent, Inc. All Rights Reserved. 003 * 004 * Project and contact information: http://www.cascading.org/ 005 * 006 * This file is part of the Cascading project. 007 * 008 * Licensed under the Apache License, Version 2.0 (the "License"); 009 * you may not use this file except in compliance with the License. 010 * You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, software 015 * distributed under the License is distributed on an "AS IS" BASIS, 016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 017 * See the License for the specific language governing permissions and 018 * limitations under the License. 019 */ 020 021 package cascading.operation.regex; 022 023 import java.beans.ConstructorProperties; 024 import java.util.regex.Matcher; 025 026 import cascading.flow.FlowProcess; 027 import cascading.operation.Function; 028 import cascading.operation.FunctionCall; 029 import cascading.operation.OperationCall; 030 import cascading.tuple.Fields; 031 import cascading.tuple.Tuple; 032 import cascading.util.Pair; 033 034 /** Class RegexGenerator will emit a new Tuple for every matched regex group. */ 035 public class RegexGenerator extends RegexOperation<Pair<Matcher, Tuple>> implements Function<Pair<Matcher, Tuple>> 036 { 037 /** 038 * Constructor RegexGenerator creates a new RegexGenerator instance. 039 * 040 * @param patternString of type String 041 */ 042 @ConstructorProperties({"patternString"}) 043 public RegexGenerator( String patternString ) 044 { 045 super( 1, Fields.size( 1 ), patternString ); 046 } 047 048 /** 049 * Constructor RegexGenerator creates a new RegexGenerator instance. 050 * 051 * @param fieldDeclaration of type Fields 052 * @param patternString of type String 053 */ 054 @ConstructorProperties({"fieldDeclaration", "patternString"}) 055 public RegexGenerator( Fields fieldDeclaration, String patternString ) 056 { 057 super( 1, fieldDeclaration, patternString ); 058 059 if( fieldDeclaration.size() != 1 ) 060 throw new IllegalArgumentException( "fieldDeclaration may only declare one field, was " + fieldDeclaration.print() ); 061 } 062 063 @Override 064 public void prepare( FlowProcess flowProcess, OperationCall<Pair<Matcher, Tuple>> operationCall ) 065 { 066 operationCall.setContext( new Pair<Matcher, Tuple>( getPattern().matcher( "" ), Tuple.size( 1 ) ) ); 067 } 068 069 @Override 070 public void operate( FlowProcess flowProcess, FunctionCall<Pair<Matcher, Tuple>> functionCall ) 071 { 072 String value = functionCall.getArguments().getString( 0 ); 073 074 if( value == null ) 075 value = ""; 076 077 Matcher matcher = functionCall.getContext().getLhs().reset( value ); 078 079 while( matcher.find() ) 080 { 081 functionCall.getContext().getRhs().set( 0, matcher.group() ); 082 functionCall.getOutputCollector().add( functionCall.getContext().getRhs() ); 083 } 084 } 085 }