org.apache.flink.table.types.inference.strategies

类 MapInputTypeStrategy

java.lang.Object

org.apache.flink.table.types.inference.strategies.MapInputTypeStrategy

所有已实现的接口:

InputTypeStrategy

@Internal
public final class MapInputTypeStrategy
extends Object
implements InputTypeStrategy

InputTypeStrategy specific for BuiltInFunctionDefinitions.MAP.

It expects at least two arguments. There must be even number of arguments. All the keys and values must have a common super type respectively.

构造器概要

构造器

构造器和说明
MapInputTypeStrategy()

方法概要

限定符和类型	方法和说明
ArgumentCount	getArgumentCount() Initial input validation based on the number of arguments.
List<Signature>	getExpectedSignatures(FunctionDefinition definition) Returns a summary of the function's expected signatures.
Optional<List<DataType>>	inferInputTypes(CallContext callContext, boolean throwOnFailure) Main logic for inferring and validating the input arguments.

从类继承的方法 java.lang.Object

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

构造器详细资料

MapInputTypeStrategy

public MapInputTypeStrategy()

方法详细资料

getArgumentCount

public ArgumentCount getArgumentCount()

从接口复制的说明: InputTypeStrategy

Initial input validation based on the number of arguments.

指定者:

getArgumentCount 在接口中 InputTypeStrategy

inferInputTypes

public Optional<List<DataType>> inferInputTypes(CallContext callContext,
                                                boolean throwOnFailure)

从接口复制的说明: InputTypeStrategy

Main logic for inferring and validating the input arguments. Returns a list of argument data types that are valid for the given call. If the returned types differ from CallContext.getArgumentDataTypes(), a casting operation can be inserted. An empty result means that the given input is invalid.

指定者:

inferInputTypes 在接口中 InputTypeStrategy

参数:

callContext - provides details about the function call

throwOnFailure - whether this function is allowed to throw an ValidationException with a meaningful exception in case the inference is not successful or if this function should simply return an empty result.

返回:

three-state result for either "true, same data types as arguments", "true, but arguments must be casted to returned data types", or "false, no inferred data types could be found"

另请参阅:

CallContext.newValidationError(String, Object...)

getExpectedSignatures

public List<Signature> getExpectedSignatures(FunctionDefinition definition)

从接口复制的说明: InputTypeStrategy

Returns a summary of the function's expected signatures.

指定者:

getExpectedSignatures 在接口中 InputTypeStrategy

参数:

definition - the function definition that defines the function currently being called.