001 /* 002 * Copyright (c) 2007-2015 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.Pattern; 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 /** 035 * Class RegexSplitter will split an incoming argument value by the given regex delimiter patternString. 036 * <p/> 037 * RegexSplitter only expects one field value. If more than one argument value is passed, only the 038 * first is handled, the remainder are ignored. 039 * <p/> 040 * Note a {@code null} valued argument passed to the parser will be converted to an empty string ({@code ""}) before 041 * the regex is applied. 042 * <p/> 043 * Any Object value will be coerced to a String type if type information is provided. See the 044 * {@link cascading.tuple.type.CoercibleType} interface to control how custom Object types are converted to String 045 * values. 046 */ 047 public class RegexSplitter extends RegexOperation<Pair<Pattern, Tuple>> implements Function<Pair<Pattern, Tuple>> 048 { 049 private final int length; 050 051 /** 052 * Constructor RegexSplitter creates a new RegexSplitter instance. 053 * 054 * @param patternString of type String 055 */ 056 @ConstructorProperties({"patternString"}) 057 public RegexSplitter( String patternString ) 058 { 059 super( 1, patternString ); 060 length = fieldDeclaration.isUnknown() ? -1 : fieldDeclaration.size(); 061 } 062 063 /** 064 * Constructor RegexOperation creates a new RegexOperation instance, where the delimiter is the tab character. 065 * 066 * @param fieldDeclaration of type Fields 067 */ 068 @ConstructorProperties({"fieldDeclaration"}) 069 public RegexSplitter( Fields fieldDeclaration ) 070 { 071 super( 1, fieldDeclaration, "\t" ); 072 length = fieldDeclaration.isUnknown() ? -1 : fieldDeclaration.size(); 073 } 074 075 /** 076 * Constructor RegexSplitter creates a new RegexSplitter instance. 077 * 078 * @param fieldDeclaration of type Fields 079 * @param patternString of type String 080 */ 081 @ConstructorProperties({"fieldDeclaration", "patternString"}) 082 public RegexSplitter( Fields fieldDeclaration, String patternString ) 083 { 084 super( 1, fieldDeclaration, patternString ); 085 length = fieldDeclaration.isUnknown() ? -1 : fieldDeclaration.size(); 086 } 087 088 @Override 089 public void prepare( FlowProcess flowProcess, OperationCall<Pair<Pattern, Tuple>> operationCall ) 090 { 091 operationCall.setContext( new Pair<Pattern, Tuple>( getPattern(), new Tuple() ) ); 092 } 093 094 @Override 095 public void operate( FlowProcess flowProcess, FunctionCall<Pair<Pattern, Tuple>> functionCall ) 096 { 097 String value = functionCall.getArguments().getString( 0 ); 098 099 if( value == null ) 100 value = ""; 101 102 Tuple output = functionCall.getContext().getRhs(); 103 104 output.clear(); 105 106 String[] split = functionCall.getContext().getLhs().split( value, length ); 107 108 for( int i = 0; i < split.length; i++ ) 109 output.add( split[ i ] ); 110 111 functionCall.getOutputCollector().add( output ); 112 } 113 }