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.Filter;
028    import cascading.operation.FilterCall;
029    
030    /**
031     * Class RegexFilter will apply the regex patternString against every input Tuple value and filter
032     * the Tuple stream accordingly.
033     * <p/>
034     * By default, Tuples that match the given pattern are kept, and Tuples that do not
035     * match are filtered out. This can be changed by setting removeMatch to true.
036     * <p/>
037     * Also, by default, the whole Tuple is matched against the given patternString (tab delimited). If matchEachElement
038     * is set to true, the pattern is applied to each Tuple value individually.
039     * <p/>
040     * This operation uses {@link java.util.regex.Matcher} internally, specifically the method {@link java.util.regex.Matcher#find()}.
041     *
042     * @see java.util.regex.Matcher
043     * @see java.util.regex.Pattern
044     */
045    public class RegexFilter extends RegexMatcher implements Filter<Matcher>
046      {
047      /** Field matchEachElement */
048      protected final boolean matchEachElement;
049    
050      /**
051       * Constructor RegexFilter creates a new RegexFilter instance.
052       *
053       * @param patternString of type String
054       */
055      @ConstructorProperties({"patternString"})
056      public RegexFilter( String patternString )
057        {
058        super( patternString );
059        this.matchEachElement = false;
060        }
061    
062      /**
063       * Constructor RegexFilter creates a new RegexFilter instance.
064       *
065       * @param patternString of type String
066       * @param removeMatch   of type boolean
067       */
068      @ConstructorProperties({"patternString", "removeMatch"})
069      public RegexFilter( String patternString, boolean removeMatch )
070        {
071        super( patternString, removeMatch );
072        this.matchEachElement = false;
073    
074        }
075    
076      /**
077       * @param patternString    of type String
078       * @param removeMatch      of type boolean, set to true if a match should be filtered
079       * @param matchEachElement of type boolean, set to true if each element should be matched individually
080       */
081      @ConstructorProperties({"patternString", "removeMatch", "matchEachElement"})
082      public RegexFilter( String patternString, boolean removeMatch, boolean matchEachElement )
083        {
084        super( patternString, removeMatch );
085        this.matchEachElement = matchEachElement;
086        }
087    
088      public boolean isMatchEachElement()
089        {
090        return matchEachElement;
091        }
092    
093      @Override
094      public boolean isRemove( FlowProcess flowProcess, FilterCall<Matcher> filterCall )
095        {
096        if( matchEachElement )
097          return matchEachElement( filterCall.getContext(), filterCall.getArguments().getTuple() );
098        else
099          return matchWholeTuple( filterCall.getContext(), filterCall.getArguments().getTuple() );
100        }
101    
102      @Override
103      public boolean equals( Object object )
104        {
105        if( this == object )
106          return true;
107        if( !( object instanceof RegexFilter ) )
108          return false;
109        if( !super.equals( object ) )
110          return false;
111    
112        RegexFilter that = (RegexFilter) object;
113    
114        if( matchEachElement != that.matchEachElement )
115          return false;
116    
117        return true;
118        }
119    
120      @Override
121      public int hashCode()
122        {
123        int result = super.hashCode();
124        result = 31 * result + ( matchEachElement ? 1 : 0 );
125        return result;
126        }
127      }