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.text;
022    
023    import java.beans.ConstructorProperties;
024    
025    import cascading.flow.FlowProcess;
026    import cascading.operation.BaseOperation;
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    
033    /** Class FieldJoiner joins the values in a Tuple with a given delimiter and stuffs the result into a new field. */
034    public class FieldJoiner extends BaseOperation<Tuple> implements Function<Tuple>
035      {
036      /** Field FIELD_NAME */
037      public static final String FIELD_NAME = "joined";
038    
039      /** Field delimiter */
040      private String delimiter = "\t";
041    
042      /**
043       * Constructor FieldJoiner creates a new FieldJoiner instance.
044       *
045       * @param delimiter of type String
046       */
047      @ConstructorProperties({"delimiter"})
048      public FieldJoiner( String delimiter )
049        {
050        this( new Fields( FIELD_NAME ) );
051        this.delimiter = delimiter;
052        }
053    
054      /**
055       * Constructor FieldJoiner creates a new FieldJoiner instance.
056       *
057       * @param fieldDeclaration of type Fields
058       */
059      @ConstructorProperties({"fieldDeclaration"})
060      public FieldJoiner( Fields fieldDeclaration )
061        {
062        super( fieldDeclaration );
063        }
064    
065      /**
066       * Constructor FieldJoiner creates a new FieldJoiner instance.
067       *
068       * @param fieldDeclaration of type Fields
069       * @param delimiter        of type String
070       */
071      @ConstructorProperties({"fieldDeclaration", "delimiter"})
072      public FieldJoiner( Fields fieldDeclaration, String delimiter )
073        {
074        super( fieldDeclaration );
075        this.delimiter = delimiter;
076        }
077    
078      /**
079       * Method getFormat returns the delimiter of this FieldJoiner object.
080       *
081       * @return the delimiter (type String) of this FieldJoiner object.
082       */
083      public String getDelimiter()
084        {
085        return delimiter;
086        }
087    
088      @Override
089      public void prepare( FlowProcess flowProcess, OperationCall<Tuple> operationCall )
090        {
091        operationCall.setContext( Tuple.size( 1 ) );
092        }
093    
094      @Override
095      public void operate( FlowProcess flowProcess, FunctionCall<Tuple> functionCall )
096        {
097        functionCall.getContext().set( 0, functionCall.getArguments().getTuple().toString( delimiter, false ) );
098        functionCall.getOutputCollector().add( functionCall.getContext() );
099        }
100    
101      @Override
102      public boolean equals( Object object )
103        {
104        if( this == object )
105          return true;
106        if( !( object instanceof FieldJoiner ) )
107          return false;
108        if( !super.equals( object ) )
109          return false;
110    
111        FieldJoiner that = (FieldJoiner) object;
112    
113        if( delimiter != null ? !delimiter.equals( that.delimiter ) : that.delimiter != null )
114          return false;
115    
116        return true;
117        }
118    
119      @Override
120      public int hashCode()
121        {
122        int result = super.hashCode();
123        result = 31 * result + ( delimiter != null ? delimiter.hashCode() : 0 );
124        return result;
125        }
126      }