Package com.espertech.esper.common.client.dataflow.util

Class DataFlowParameterResolution

java.lang.Object

com.espertech.esper.common.client.dataflow.util.DataFlowParameterResolution

public class DataFlowParameterResolution
extends Object

Utility for data flow parameter resolution that considers parameter providers that are passed in.

Constructor Summary

Constructors

Constructor	Description
DataFlowParameterResolution()

Method Summary

Modifier and Type	Method	Description
static Map<String,Object>	resolveMap(String name, Map<String,Object> evals, DataFlowOpInitializeContext context)	Resolve all entries in the map by first looking at the parameter value provider and by using the evaluator if one was provided or returning the provided value if no evaluator was found.
static Number	resolveNumber(String name, ExprEvaluator optionalEvaluator, Number defaultValue, DataFlowOpInitializeContext context)	Resolve a number value by first looking at the parameter value provider and by using the evaluator if one was provided, returning the default value if no value was found and no evaluator was provided.
static <T> T	resolveOptionalInstance(String name, Map<String,Object> configuration, Class<T> clazz, DataFlowOpInitializeContext context)	Resolve an instance from a class-name map.
static String	resolveStringOptional(String name, ExprEvaluator optionalEvaluator, DataFlowOpInitializeContext context)	Resolve a string value by first looking at the parameter value provider and by using the evaluator if one was provided or returning null if no value was found.
static String	resolveStringRequired(String name, ExprEvaluator optionalEvaluator, DataFlowOpInitializeContext context)	Resolve a string value by first looking at the parameter value provider and by using the evaluator if one was provided, throwing an exception if no value was provided.
static <T> T	resolveWithDefault(String name, ExprEvaluator optionalEvaluator, T defaultValue, Class<T> clazz, DataFlowOpInitializeContext context)	Resolve a typed value by first looking at the parameter value provider and by using the evaluator if one was provided or returning the provided default value if no value was found.

Methods inherited from class java.lang.Object

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

Constructor Details

DataFlowParameterResolution

public DataFlowParameterResolution()

Method Details

resolveNumber

public static Number resolveNumber(String name,
 ExprEvaluator optionalEvaluator,
 Number defaultValue,
 DataFlowOpInitializeContext context)

Resolve a number value by first looking at the parameter value provider and by using the evaluator if one was provided, returning the default value if no value was found and no evaluator was provided.

Parameters:

name - parameter name

optionalEvaluator - evaluator

defaultValue - default

context - initialization context

Returns:

value

resolveStringRequired

public static String resolveStringRequired(String name,
 ExprEvaluator optionalEvaluator,
 DataFlowOpInitializeContext context)

Resolve a string value by first looking at the parameter value provider and by using the evaluator if one was provided, throwing an exception if no value was provided.

Parameters:

name - parameter name

optionalEvaluator - evaluator

context - initialization context

Returns:

value

Throws:

EPException - if no value was found

resolveStringOptional

public static String resolveStringOptional(String name,
 ExprEvaluator optionalEvaluator,
 DataFlowOpInitializeContext context)

Resolve a string value by first looking at the parameter value provider and by using the evaluator if one was provided or returning null if no value was found.

Parameters:

name - parameter name

optionalEvaluator - evaluator

context - initialization context

Returns:

value

Throws:

EPException - if no value was found

resolveWithDefault

public static <T> T resolveWithDefault(String name,
 ExprEvaluator optionalEvaluator,
 T defaultValue,
 Class<T> clazz,
 DataFlowOpInitializeContext context)

Resolve a typed value by first looking at the parameter value provider and by using the evaluator if one was provided or returning the provided default value if no value was found.

Type Parameters:

T - the type of value

Parameters:

name - parameter name

optionalEvaluator - evaluator

context - initialization context

clazz - type of value

defaultValue - default value

Returns:

value

resolveOptionalInstance

public static <T> T resolveOptionalInstance(String name,
 Map<String,Object> configuration,
 Class<T> clazz,
 DataFlowOpInitializeContext context)

Resolve an instance from a class-name map.

Type Parameters:

T - type of value returned

Parameters:

name - parameter name

configuration - map with key 'class' for the class name

clazz - expected interface or supertype

context - initialization context

Returns:

instance

resolveMap

public static Map<String,Object> resolveMap(String name,
 Map<String,Object> evals,
 DataFlowOpInitializeContext context)

Resolve all entries in the map by first looking at the parameter value provider and by using the evaluator if one was provided or returning the provided value if no evaluator was found.

Parameters:

name - parameter name

evals - map of properties with either evaluator or constant type

context - initialization context

Returns:

value