org.apache.flink.table.functions

接口 SpecializedFunction.ExpressionEvaluator

所有超级接口:

Serializable

封闭接口:

SpecializedFunction

public static interface SpecializedFunction.ExpressionEvaluator
extends Serializable

Serializable factory that can be passed into a UserDefinedFunction for evaluating previously defined expression during runtime.

另请参阅:

SpecializedFunction.ExpressionEvaluatorFactory.createEvaluator(Expression, DataType, DataTypes.Field...), SpecializedFunction.ExpressionEvaluatorFactory.createEvaluator(BuiltInFunctionDefinition, DataType, DataType...)

方法概要

限定符和类型	方法和说明
default void	close() Closes the runtime implementation for expression evaluation.
MethodHandle	open(FunctionContext context) Creates and initializes runtime implementation for expression evaluation.

方法详细资料

open

MethodHandle open(FunctionContext context)

Creates and initializes runtime implementation for expression evaluation. The returned MethodHandle should be stored in a transient variable and can be invoked via MethodHandle.invokeExact(Object...) using the conversion classes previously defined via the passed DataTypes.

This method should be called in UserDefinedFunction.open(FunctionContext).

close

default void close()

Closes the runtime implementation for expression evaluation. It performs clean up work.

This method should be called in UserDefinedFunction.close().