cascading.operation.assertion
Class AssertExpression

java.lang.Object
  extended by cascading.operation.BaseOperation<ScriptOperation.Context>
      extended by cascading.operation.expression.ScriptOperation
          extended by cascading.operation.expression.ExpressionOperation
              extended by cascading.operation.assertion.AssertExpression
All Implemented Interfaces:
DeclaresResults, Assertion<ScriptOperation.Context>, Operation<ScriptOperation.Context>, PlannedOperation<ScriptOperation.Context>, ValueAssertion<ScriptOperation.Context>, Traceable, Serializable

public class AssertExpression
extends ExpressionOperation
implements ValueAssertion<ScriptOperation.Context>

Class AssertExpression dynamically resolves a given expression using argument Tuple values. Any Tuple that returns true for the given expression pass the assertion. This Assertion is based on the Janino compiler.

Specifically this filter uses the ExpressionEvaluator, thus the syntax from that class is inherited here.

An expression may use field names directly as parameters in the expression, or field positions with the syntax "$n", where n is an integer.

Given an argument tuple with the fields "a" and "b", the following expression returns true:
a + b == $0 + $1

Further, the types of the tuple elements will be coerced into the given parameterTypes. Regardless of the actual tuple element values, they will be converted to the types expected by the expression.

See Also:
Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from class cascading.operation.expression.ScriptOperation
ScriptOperation.Context
 
Field Summary
 
Fields inherited from class cascading.operation.expression.ScriptOperation
block, parameterNames, parameterTypes, returnType
 
Fields inherited from class cascading.operation.BaseOperation
fieldDeclaration, numArgs, trace
 
Fields inherited from interface cascading.operation.Operation
ANY
 
Constructor Summary
AssertExpression(Fields fieldDeclaration, String expression, String[] parameterNames, Class[] parameterTypes)
          Constructor AssertExpression creates a new AssertExpression instance.
AssertExpression(String expression, Class parameterType)
          Constructor ExpressionFilter creates a new ExpressionFilter instance.
 
Method Summary
 void doAssert(FlowProcess flowProcess, ValueAssertionCall<ScriptOperation.Context> assertionCall)
          Method doAssert performs the assertion.
 boolean supportsPlannerLevel(PlannerLevel plannerLevel)
           
 
Methods inherited from class cascading.operation.expression.ExpressionOperation
getEvaluator, getExpression, guessParameterNames
 
Methods inherited from class cascading.operation.expression.ScriptOperation
equals, evaluate, getBlock, getParameterNames, getParameterTypes, getReturnType, hashCode, prepare
 
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
 
Methods inherited from interface cascading.operation.Operation
cleanup, flush, getFieldDeclaration, getNumArgs, isSafe, prepare
 

Constructor Detail

AssertExpression

@ConstructorProperties(value={"expression","parameterType"})
public AssertExpression(String expression,
                                                   Class parameterType)
Constructor ExpressionFilter creates a new ExpressionFilter instance.

Parameters:
expression - of type String
parameterType - of type Class

AssertExpression

@ConstructorProperties(value={"fieldDeclaration","expression","parameterNames","parameterTypes"})
public AssertExpression(Fields fieldDeclaration,
                                                   String expression,
                                                   String[] parameterNames,
                                                   Class[] parameterTypes)
Constructor AssertExpression creates a new AssertExpression instance.

Parameters:
fieldDeclaration - of type Fields
expression - of type String
parameterNames - of type String[]
parameterTypes - of type Class[]
Method Detail

supportsPlannerLevel

public boolean supportsPlannerLevel(PlannerLevel plannerLevel)
Specified by:
supportsPlannerLevel in interface PlannedOperation<ScriptOperation.Context>

doAssert

public void doAssert(FlowProcess flowProcess,
                     ValueAssertionCall<ScriptOperation.Context> assertionCall)
Description copied from interface: ValueAssertion
Method doAssert performs the assertion.

Specified by:
doAssert in interface ValueAssertion<ScriptOperation.Context>
Parameters:
flowProcess - of type FlowProcess
assertionCall - of type ValueAssertionCall


Copyright © 2007-2015 Concurrent, Inc. All Rights Reserved.