cascading.operation.expression
Class ExpressionOperation

java.lang.Object
  extended by cascading.operation.BaseOperation<ExpressionOperation.Context>
      extended by cascading.operation.expression.ExpressionOperation
All Implemented Interfaces:
Operation<ExpressionOperation.Context>, Serializable
Direct Known Subclasses:
AssertExpression, ExpressionFilter, ExpressionFunction

public class ExpressionOperation
extends BaseOperation<ExpressionOperation.Context>

Class ExpressionOperation is the base class for ExpressionFunction, ExpressionFilter, AssertExpression.

See Also:
Serialized Form

Nested Class Summary
static class ExpressionOperation.Context
           
 
Field Summary
protected  String expression
          Field expression
 
Fields inherited from class cascading.operation.BaseOperation
fieldDeclaration, numArgs, trace
 
Fields inherited from interface cascading.operation.Operation
ANY
 
Constructor Summary
protected ExpressionOperation(Fields fieldDeclaration, String expression)
           
protected ExpressionOperation(Fields fieldDeclaration, String expression, Class parameterType)
           
protected ExpressionOperation(Fields fieldDeclaration, String expression, String[] parameterNames, Class[] parameterTypes)
           
protected ExpressionOperation(String expression, Class parameterType)
           
protected ExpressionOperation(String expression, String[] parameterNames, Class[] parameterTypes)
           
 
Method Summary
 boolean equals(Object object)
           
protected  Comparable evaluate(ExpressionOperation.Context context, TupleEntry input)
          Performs the actual expression evaluation.
 int hashCode()
           
 void prepare(FlowProcess flowProcess, OperationCall<ExpressionOperation.Context> operationCall)
          Method prepare does nothing, and may safely be overridden.
 
Methods inherited from class cascading.operation.BaseOperation
cleanup, flush, getFieldDeclaration, getNumArgs, getTrace, isSafe, printOperationInternal, toString, toStringInternal
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

expression

protected final String expression
Field expression

Constructor Detail

ExpressionOperation

@ConstructorProperties(value={"fieldDeclaration","expression"})
protected ExpressionOperation(Fields fieldDeclaration,
                                                         String expression)

ExpressionOperation

@ConstructorProperties(value={"fieldDeclaration","expression","parameterType"})
protected ExpressionOperation(Fields fieldDeclaration,
                                                         String expression,
                                                         Class parameterType)

ExpressionOperation

@ConstructorProperties(value={"fieldDeclaration","expression","parameterNames","parameterTypes"})
protected ExpressionOperation(Fields fieldDeclaration,
                                                         String expression,
                                                         String[] parameterNames,
                                                         Class[] parameterTypes)

ExpressionOperation

@ConstructorProperties(value={"fieldDeclaration","parameterType"})
protected ExpressionOperation(String expression,
                                                         Class parameterType)

ExpressionOperation

@ConstructorProperties(value={"expression","parameterNames","parameterTypes"})
protected ExpressionOperation(String expression,
                                                         String[] parameterNames,
                                                         Class[] parameterTypes)
Method Detail

prepare

public void prepare(FlowProcess flowProcess,
                    OperationCall<ExpressionOperation.Context> operationCall)
Description copied from class: BaseOperation
Method prepare does nothing, and may safely be overridden.

Specified by:
prepare in interface Operation<ExpressionOperation.Context>
Overrides:
prepare in class BaseOperation<ExpressionOperation.Context>

evaluate

protected Comparable evaluate(ExpressionOperation.Context context,
                              TupleEntry input)
Performs the actual expression evaluation.

Parameters:
context -
input - of type TupleEntry @return Comparable

equals

public boolean equals(Object object)
Overrides:
equals in class BaseOperation<ExpressionOperation.Context>

hashCode

public int hashCode()
Overrides:
hashCode in class BaseOperation<ExpressionOperation.Context>


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