    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.tuple.type;
    022
    023    import java.lang.reflect.Type;
    024    import java.text.ParseException;
    025    import java.text.SimpleDateFormat;
    026    import java.util.Calendar;
    027    import java.util.Date;
    028    import java.util.Locale;
    029    import java.util.TimeZone;
    030
    031    import cascading.CascadingException;
    032    import cascading.util.Util;
    033
    034    /**
    035     * Class DateCoercibleType is an implementation of {@link CoercibleType}.
    036     * <p/>
    037     * Given a {@code dateFormatString}, using the {@link SimpleDateFormat} format, this CoercibleType
    038     * will convert a value from the formatted string to a {@code Long} canonical type and back.
    039     * <p/>
    040     * This class when presented with a Long timestamp value will assume the value is in UTC.
    041     * <p/>
    042     * See {@link cascading.operation.text.DateParser} and {@link cascading.operation.text.DateFormatter} for similar
    043     * Operations for use within a pipe assembly.
    044     */
    045    public class DateType implements CoercibleType<Long>
    046      {
    047      /** Field zone */
    048      protected TimeZone zone;
    049      /** Field locale */
    050      protected Locale locale;
    051      /** Field dateFormatString */
    052      protected String dateFormatString;
    053      /** Field dateFormat */
    054      private transient SimpleDateFormat dateFormat;
    055
    056      /**
    057       * Create a new DateType instance.
    058       *
    059       * @param dateFormatString
    060       * @param zone
    061       * @param locale
    062       */
    063      public DateType( String dateFormatString, TimeZone zone, Locale locale )
    064        {
    065        this.zone = zone;
    066        this.locale = locale;
    067        this.dateFormatString = dateFormatString;
    068        }
    069
    070      public DateType( String dateFormatString, TimeZone zone )
    071        {
    072        this.zone = zone;
    073        this.dateFormatString = dateFormatString;
    074        }
    075
    076      /**
    077       * Create a new DateType instance.
    078       *
    079       * @param dateFormatString
    080       */
    081      public DateType( String dateFormatString )
    082        {
    083        this.dateFormatString = dateFormatString;
    084        }
    085
    086      @Override
    087      public Class getCanonicalType()
    088        {
    089        return Long.TYPE;
    090        }
    091
    092      public SimpleDateFormat getDateFormat()
    093        {
    094        if( dateFormat != null )
    095          return dateFormat;
    096
    097        dateFormat = new SimpleDateFormat( dateFormatString, getLocale() );
    098
    099        dateFormat.setTimeZone( getZone() );
    100
    101        return dateFormat;
    102        }
    103
    104      private Locale getLocale()
    105        {
    106        if( locale != null )
    107          return locale;
    108
    109        return Locale.getDefault();
    110        }
    111
    112      private TimeZone getZone()
    113        {
    114        if( zone != null )
    115          return zone;
    116
    117        return TimeZone.getTimeZone( "UTC" );
    118        }
    119
    120      protected Calendar getCalendar()
    121        {
    122        return Calendar.getInstance( TimeZone.getTimeZone( "UTC" ), getLocale() );
    123        }
    124
    125      @Override
    126      public Long canonical( Object value )
    127        {
    128        if( value == null )
    129          return null;
    130
    131        Class from = value.getClass();
    132
    133        if( from == String.class )
    134          return parse( (String) value ).getTime();
    135
    136        if( from == Date.class )
    137          return ( (Date) value ).getTime(); // in UTC
    138
    139        if( from == Long.class || from == long.class )
    140          return (Long) value;
    141
    142        throw new CascadingException( "unknown type coercion requested from: " + Util.getTypeName( from ) );
    143        }
    144
    145      @Override
    146      public Object coerce( Object value, Type to )
    147        {
    148        if( value == null )
    149          return null;
    150
    151        Class from = value.getClass();
    152
    153        if( from != Long.class )
    154          throw new IllegalStateException( "was not normalized" );
    155
    156        // no coercion, or already in canonical form
    157        if( to == Long.class || to == long.class || to == Object.class )
    158          return value;
    159
    160        if( to == String.class )
    161          {
    162          Calendar calendar = getCalendar();
    163
    164          calendar.setTimeInMillis( (Long) value );
    165
    166          return getDateFormat().format( calendar.getTime() );
    167          }
    168
    169        throw new CascadingException( "unknown type coercion requested, from: " + Util.getTypeName( from ) + " to: " + Util.getTypeName( to ) );
    170        }
    171
    172      private Date parse( String value )
    173        {
    174        try
    175          {
    176          return getDateFormat().parse( value );
    177          }
    178        catch( ParseException exception )
    179          {
    180          throw new CascadingException( "unable to parse value: " + value + " with format: " + dateFormatString );
    181          }
    182        }
    183
    184      @Override
    185      public String toString()
    186        {
    187        final StringBuilder sb = new StringBuilder( "DateType{" );
    188        sb.append( "dateFormatString='" ).append( dateFormatString ).append( '\'' );
    189        sb.append( '}' );
    190        return sb.toString();
    191        }
    192      }