Package org.apache.solr.client.solrj.io.ops

Class ReplaceOperation

java.lang.Object

org.apache.solr.client.solrj.io.ops.ReplaceOperation

All Implemented Interfaces:

Serializable, StreamOperation, Expressible

public class ReplaceOperation
extends Object
implements StreamOperation

Replaces some tuple value with another. The replacement value can be either a given value or the value of another field in the tuple. The expression for a replace operation can be of multiple forms:

replace(fieldA, 0, withValue=100) // for fieldA if equals 0 then set to 100

replace(fieldA, null, withValue=0) // for fieldA if null then set to 0

replace(fieldA, null, withField=fieldB) // for fieldA if null then set to the value of fieldB (if fieldB is null then fieldA will end up as null)

replace(fieldA, 0, withField=fieldB) // for fieldA if 0 then set to the value of fieldB (if fieldB is 0 then fieldA will end up as 0)

replace(fieldA, "Izzy and Kayden", withValue="my kids")

You can also construct these without the field name in the expression but that does require that you provide the field name during construction. This is most useful during metric calculation because when calculating a metric you have already provided a field name in the metric so there is no reason to have to provide the field name again in the operation sum(fieldA, replace(null, withValue=0)) // performs the replacement on fieldA

Equality is determined by the standard type .equals() functions.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
ReplaceOperation(String forField, StreamExpression expression, StreamFactory factory)
ReplaceOperation(StreamExpression expression, StreamFactory factory)

Method Summary

Modifier and Type	Method	Description
void	operate(Tuple tuple)
Explanation	toExplanation(StreamFactory factory)	Returns an explanation about the stream object
StreamExpressionParameter	toExpression(StreamFactory factory)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReplaceOperation

public ReplaceOperation(StreamExpression expression,
                        StreamFactory factory)
                 throws IOException

Throws:

IOException

ReplaceOperation

public ReplaceOperation(String forField,
                        StreamExpression expression,
                        StreamFactory factory)
                 throws IOException

Throws:

IOException

Method Detail

operate

public void operate(Tuple tuple)

Specified by:

operate in interface StreamOperation

toExpression

public StreamExpressionParameter toExpression(StreamFactory factory)
                                       throws IOException

Specified by:

toExpression in interface Expressible

Throws:

IOException

toExplanation

public Explanation toExplanation(StreamFactory factory)
                          throws IOException

Description copied from interface: Expressible

Returns an explanation about the stream object

Specified by:

toExplanation in interface Expressible

Parameters:

factory - Stream factory for this, contains information about the function name

Returns:

Explanation about this stream object containing explanations of any child stream objects

Throws:

IOException - throw on any error