/*
* Copyright (c) 2007-2014 Concurrent, Inc. All Rights Reserved.
*
* Project and contact information: http://www.cascading.org/
*
* This file is part of the Cascading project.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cascading.lingual.type;
import java.lang.reflect.Type;
import java.util.Calendar;
import java.util.Date;
import cascading.CascadingException;
import cascading.util.Util;
import com.fasterxml.jackson.annotation.JsonTypeName;
import org.eigenbase.sql.type.SqlTypeName;
import org.eigenbase.util14.DateTimeUtil;
import org.eigenbase.util14.ZonelessDate;
import org.eigenbase.util14.ZonelessDatetime;
/**
* Handles conversion to and from the DATA data type in SQL. Since the DATE type is defined as not having a
* timezone and having only yyyy-mm-dd precision we truncate rather than convert to preserve the symmetry of conversion. The
* dates "2013-03-05 09:04:57 GMT" and "2013-03-05 04:04:57 -0700" are considered identical DATE values even though they represent
* different actual calender times. This is in line with the convention that many databases have of allowing an implicit conversion
* of DATE to TIMESTAMP and setting it to "yyyy-mm-dd 00:00:00" of their set default timezone.
* <p/>
* Symmetry is not guaranteed across Lingual jobs running in JVMs set to different timezones. Set UTC time on all servers or use the
* TIMESTAMP datatype and {@link SQLDateTimeCoercibleType} since those are defined to represent a more precise time.
*/
@JsonTypeName("SQLDate")
public class SQLDateCoercibleType extends SQLDateTimeCoercibleType
{
public SQLDateCoercibleType()
{
super( SqlTypeName.DATE );
}
protected ZonelessDatetime parse( String value )
{
return ZonelessDate.parse( value );
}
@Override
protected ZonelessDatetime createInstance()
{
return new ZonelessDate();
}
@Override
public Class getCanonicalType()
{
return Integer.class;
}
@Override
public Object canonical( Object value )
{
if( value == null )
return null;
Class from = value.getClass();
if( from == String.class )
{
Calendar calendar = DateTimeUtil.parseDateFormat( (String) value, DateTimeUtil.DateFormatStr, DateTimeUtil.defaultZone );
return truncateDate( calendar.getTimeInMillis() );
}
if( Date.class.isAssignableFrom( from ) )
{
Date fromDate = (Date) value;
return truncateDate( fromDate.getTime() );
}
if( from == Integer.class || from == int.class )
return value;
if( from == Long.class || from == long.class )
return ( (Long) value ).intValue();
throw new CascadingException( "unknown type coercion requested from: " + Util.getTypeName( from ) );
}
@Override
public Object coerce( Object value, Type to )
{
if( value == null )
return null;
Class from = value.getClass();
if( from != Integer.class )
throw new IllegalStateException( "was not normalized" );
// no coercion, or already in canonical form
if( to == Integer.class || to == int.class || to == Object.class )
return value;
if( to == Long.class )
return ( (Integer) value ).intValue();
// offset by the current timezone so we get only yyyy-mm-hh precision per the spec for DATE
// Even with a "cast" of DATE to TIMESTAMP the value should be considered "yyyy-mm-hh 00:00:00"
Calendar calendar = Calendar.getInstance();
int timezoneOffset = calendar.get( Calendar.ZONE_OFFSET ) + calendar.get( Calendar.DST_OFFSET );
long shiftedTime = ( ( (Integer) value ).longValue() * MILLIS_PER_DAY ) + timezoneOffset;
ZonelessDatetime date = createInstance();
date.setZonedTime( shiftedTime, DateTimeUtil.defaultZone );
if( to == String.class )
return date.toString();
if( to == java.sql.Date.class )
return new java.sql.Date( date.getJdbcDate( DateTimeUtil.defaultZone ) );
if( to == java.sql.Timestamp.class )
return new java.sql.Timestamp( date.getJdbcTimestamp( DateTimeUtil.defaultZone ) );
if( to == java.sql.Time.class )
return new java.sql.Time( date.getJdbcTime( DateTimeUtil.defaultZone ) );
throw new CascadingException( "unknown type coercion requested, from: " + Util.getTypeName( from ) + " to: " + Util.getTypeName( to ) );
}
/** Converts a long to an int that can be used to represent the DATE datatype. */
protected int truncateDate( long timestamp )
{
// The precision for DATE in SQL is only yyyy-mm-hh so truncate before rounding.
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis( timestamp );
calendar.set( Calendar.HOUR_OF_DAY, 0 );
calendar.set( Calendar.MINUTE, 0 );
calendar.set( Calendar.SECOND, 0 );
calendar.set( Calendar.MILLISECOND, 0 );
long calTime = calendar.getTimeInMillis();
return (int) Math.ceil( (double) calTime / MILLIS_PER_DAY );
}
}