Examples of cascading.tuple.type.CoercibleType

cascading.tuple.type.CoercibleType

Interface CoercibleType allows {@link cascading.tuple.Fields} instances to be extended with customtype information.

It is the role of implementations of this interface to maintain a canonical representation of a given value and to allow for coercions between some type representation to the canonical type and back.

For example, if a field in a text delimited file is a date, ie. {@code 28/Dec/2012:16:17:12:931 -0800}it may be beneficial for the internal representation to be a {@link Long} value for performance reasons.

Note CoercibleType used in conjunction with the TextDelimited parsers is not a replacement for using a pipe assembly to cleanse data. Pushing data cleansing down to a {@link cascading.tap.Tap} and{@link cascading.scheme.Scheme} may not provide the flexibility and robustness expected.

CoercibleTypes are a convenience when the input data is of high quality or was previously written out using a CoercibleType instance.

The CoercibleTypes further allow the Cascading planner to perform type checks during joins. If no {@link java.util.Comparator} is in use, and lhs and rhs fields are not the same type, the planner will throw anexception.

    {
    final SimpleDateFormat dateFormat = new SimpleDateFormat( "dd/MMM/yyyy:HH:mm:ss:SSS Z" );
    Date date = new Date();
    String stringDate = dateFormat.format( date );


    CoercibleType coercible = new DateType( "dd/MMM/yyyy:HH:mm:ss:SSS Z", TimeZone.getDefault() );


    Fields fields = Fields.size( 2 ).applyTypes( coercible, long.class );
    Tuple tuple = new Tuple( date.getTime(), date.getTime() );


    TupleEntry results = new TupleEntry( fields, tuple );

    {
    final SimpleDateFormat dateFormat = new SimpleDateFormat( "dd/MMM/yyyy:HH:mm:ss:SSS Z" );
    Date date = new Date();
    String stringDate = dateFormat.format( date );


    CoercibleType coercible = new DateType( "dd/MMM/yyyy:HH:mm:ss:SSS Z", TimeZone.getDefault() );


    Fields fields = Fields.size( 5 ).applyTypes( coercible, coercible, coercible, coercible, long.class );
    Tuple tuple = Tuple.size( 5 );


    TupleEntry results = new TupleEntry( fields, tuple );

  @Test
  public void testCoerceIterable()
    {
    final SimpleDateFormat dateFormat = new SimpleDateFormat( "dd/MMM/yyyy:HH:mm:ss:SSS Z" );


    CoercibleType coercible = new DateType( "dd/MMM/yyyy:HH:mm:ss:SSS Z", TimeZone.getDefault() );


    Date date = new Date();
    String stringDate = dateFormat.format( date );
    Tuple tuple = Tuple.size( 4 );

Examples of cascading.tuple.type.CoercibleType

Related Classes of cascading.tuple.type.CoercibleType