Package com.espertech.esper.common.internal.epl.expression.etc

Class ExprEvalSystemProperty

java.lang.Object

com.espertech.esper.common.internal.epl.expression.core.ExprNodeBase

com.espertech.esper.common.internal.epl.expression.etc.ExprEvalSystemProperty

All Implemented Interfaces:

ExprEvaluator, ExprForge, ExprNode, ExprNodeRenderable, ExprValidator

public class ExprEvalSystemProperty
extends ExprNodeBase
implements ExprForge, ExprEvaluator

Field Summary

Fields

Modifier and Type	Field	Description
static final String	SYSTEM_PROPETIES_NAME

Fields inherited from interface com.espertech.esper.common.internal.epl.expression.core.ExprEvaluator

EPTYPE, EPTYPEARRAY

Constructor Summary

Constructors

Constructor	Description
ExprEvalSystemProperty(String systemPropertyName)

Method Summary

Modifier and Type	Method	Description
boolean	equalsNode(ExprNode other, boolean ignoreStreamPrefix)	Return true if a expression node semantically equals the current node, or false if not.
Object	evaluate(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext context)	Evaluate event tuple and return result.
CodegenExpression	evaluateCodegen(EPTypeClass requiredType, CodegenMethodScope codegenMethodScope, ExprForgeCodegenSymbol exprSymbol, CodegenClassScope codegenClassScope)
EPTypeClass	getEvaluationType()
ExprEvaluator	getExprEvaluator()
ExprForge	getForge()
ExprForgeConstantType	getForgeConstantType()
ExprNodeRenderable	getForgeRenderable()
ExprPrecedenceEnum	getPrecedence()	Returns precedence.
void	toPrecedenceFreeEPL(StringWriter writer, ExprNodeRenderableFlags flags)
ExprNode	validate(ExprValidationContext validationContext)

Methods inherited from class com.espertech.esper.common.internal.epl.expression.core.ExprNodeBase

accept, accept, acceptChildnodes, addChildNode, addChildNodes, addChildNodeToFront, checkValidated, checkValidatedException, getChildNodes, replaceUnlistedChildNode, setChildNode, setChildNodes, toEPL

Methods inherited from class java.lang.Object

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

Field Details

SYSTEM_PROPETIES_NAME

public static final String SYSTEM_PROPETIES_NAME

See Also:

• Constant Field Values

Constructor Details

ExprEvalSystemProperty

public ExprEvalSystemProperty(String systemPropertyName)

Method Details

getForge

public ExprForge getForge()

Specified by:

getForge in interface ExprNode

validate

public ExprNode validate(ExprValidationContext validationContext)
                  throws ExprValidationException

Specified by:

validate in interface ExprValidator

Throws:

ExprValidationException

getExprEvaluator

public ExprEvaluator getExprEvaluator()

Specified by:

getExprEvaluator in interface ExprForge

evaluateCodegen

public CodegenExpression evaluateCodegen(EPTypeClass requiredType,
 CodegenMethodScope codegenMethodScope,
 ExprForgeCodegenSymbol exprSymbol,
 CodegenClassScope codegenClassScope)

Specified by:

evaluateCodegen in interface ExprForge

getEvaluationType

public EPTypeClass getEvaluationType()

Specified by:

getEvaluationType in interface ExprForge

getForgeConstantType

public ExprForgeConstantType getForgeConstantType()

Specified by:

getForgeConstantType in interface ExprForge

evaluate

public Object evaluate(EventBean[] eventsPerStream,
 boolean isNewData,
 ExprEvaluatorContext context)

Description copied from interface: ExprEvaluator

Evaluate event tuple and return result.

Specified by:

evaluate in interface ExprEvaluator

Parameters:

eventsPerStream - - event tuple

isNewData - - indicates whether we are dealing with new data (istream) or old data (rstream)

context - context for expression evaluation

Returns:

evaluation result, a boolean value for OR/AND-type evalution nodes.

getForgeRenderable

public ExprNodeRenderable getForgeRenderable()

Specified by:

getForgeRenderable in interface ExprForge

toPrecedenceFreeEPL

public void toPrecedenceFreeEPL(StringWriter writer,
 ExprNodeRenderableFlags flags)

Specified by:

toPrecedenceFreeEPL in class ExprNodeBase

getPrecedence

public ExprPrecedenceEnum getPrecedence()

Description copied from interface: ExprNode

Returns precedence.

Specified by:

getPrecedence in interface ExprNode

Returns:

precedence

equalsNode

public boolean equalsNode(ExprNode other,
 boolean ignoreStreamPrefix)

Description copied from interface: ExprNode

Return true if a expression node semantically equals the current node, or false if not.

Concrete implementations should compare the type and any additional information that impact the evaluation of a node.

Specified by:

equalsNode in interface ExprNode

Parameters:

other - to compare to

ignoreStreamPrefix - when the equals-comparison can ignore prefix of event properties

Returns:

true if semantically equal, or false if not equals