Package com.streambase.sb

Class TupleCopier

java.lang.Object

com.streambase.sb.TupleCopier

public class TupleCopier
extends Object

A utility class which copies the fields from one tuple to another. TupleCopier uses the given schemas to determine which fields to copy from one Tuple to another. The strict flag on the ctor determines if an Exception is thrown if the fields in the destination schema do not match the fields in the source schema. Fields are matched by name and type. With the strict flag set to false the TupleCopier will only copy the fields between the source and destination that match field name and type. TupleCopier is more efficient than using Tuple's getField(), setField() methods to copy portions of a tuple. TupleCopier's constructor sets up the TupleCopier so that repeated calls to copyTuple() are more efficient. If a full copy is desired Tuple.clone() is probably a more efficient option. An example usage:

     ...
     TupleCopier input2OutputCopier = new TupleCopier(inputSchema, outputSchema, true);
     
     while (true) {
        outputTuple.clear();
        input2OutputCopier.copyTuple(getInputTuple(), outputTuple);
        sendOutput(port, outputTuple);
     }
     
 

Since:

6.4.5

See Also:

Tuple.clone()

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	TupleCopier.Options	Options for this TupleCopier

Constructor Summary

Constructors

Constructor	Description
TupleCopier(Schema sourceSchema, Schema destSchema, boolean strict)	Create the TupleCopier.
TupleCopier(Schema sourceSchema, Schema destSchema, EnumSet<TupleCopier.Options> options)	Create the TupleCopier.

Method Summary

Modifier and Type	Method	Description
protected static List<?>	copyList(com.streambase.sb.DataTypeCopier fieldCopier, CompleteDataType destType, List<?> sourceList)	a common method to do the list coping
void	copyTuple(Tuple sourceTuple, Tuple destTuple)	Copy the fields from the sourceTuple to the destTuple.

Methods inherited from class java.lang.Object

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

Constructor Detail

TupleCopier

public TupleCopier(Schema sourceSchema,
                   Schema destSchema,
                   boolean strict)
            throws TupleException

Create the TupleCopier. Do some up front error checking and setting up Schema maps. This constructor will create a TupleCopier with #CopyByName semantics.

Parameters:

sourceSchema - The schema of the source Tuple

destSchema - The schema of the destination tuple

strict - set to true will throw exceptions if schema fields do not match by name and type. Set to false and the TupleCopier will copy only fields that match by name and type.

Throws:

TupleException - with strict on if the fields do not match by name and type

TupleCopier

public TupleCopier(Schema sourceSchema,
                   Schema destSchema,
                   EnumSet<TupleCopier.Options> options)
            throws TupleException

Create the TupleCopier. Do some up front error checking and setting up Schema maps.

Parameters:

sourceSchema - The schema of the source Tuple

destSchema - The schema of the destination tuple

options - options from TupleCopier.Options

Throws:

TupleException - with strict on if the fields do not match by name and type

Since:

7.0

Method Detail

copyTuple

public void copyTuple(Tuple sourceTuple,
                      Tuple destTuple)
               throws TupleException

Copy the fields from the sourceTuple to the destTuple. It is assumed that the destination Tuple is either new or has been cleared.

Parameters:

sourceTuple - the source tuple

destTuple - the cleared destination tuple

Throws:

TupleException - on field copy errors

copyList

protected static List<?> copyList(com.streambase.sb.DataTypeCopier fieldCopier,
                                  CompleteDataType destType,
                                  List<?> sourceList)
                           throws TupleException

a common method to do the list coping

Parameters:

fieldCopier - the field copier

destType - the dest type

sourceList - the source list

Returns:

a copy of the list or null if the sourceList was null

Throws:

TupleException - on error