org.apache.flink.table.typeutils

Class FieldInfoUtils

java.lang.Object

org.apache.flink.table.typeutils.FieldInfoUtils

public class FieldInfoUtils
extends Object

Utility methods for extracting names and indices of fields from different TypeInformations.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FieldInfoUtils.TypeInfoSchema Describes fields' names, indices and DataTypes extracted from a TypeInformation and possibly transformed via Expression application.

Method Summary

Modifier and Type	Method and Description
static int[]	getFieldIndices(TypeInformation<?> inputType) Returns field indexes for a given TypeInformation.
static <A> String[]	getFieldNames(TypeInformation<A> inputType) Returns field names for a given TypeInformation.
static <A> String[]	getFieldNames(TypeInformation<A> inputType, List<String> existingNames) Returns field names for a given TypeInformation.
static <A> FieldInfoUtils.TypeInfoSchema	getFieldsInfo(TypeInformation<A> inputType) Returns a FieldInfoUtils.TypeInfoSchema for a given TypeInformation.
static <A> FieldInfoUtils.TypeInfoSchema	getFieldsInfo(TypeInformation<A> inputType, Expression[] expressions) Returns a FieldInfoUtils.TypeInfoSchema for a given TypeInformation.
static TypeInformation<?>[]	getFieldTypes(TypeInformation<?> inputType) Returns field types for a given TypeInformation.
static <A> void	validateInputTypeInfo(TypeInformation<A> typeInfo) Validate if class represented by the typeInfo is static and globally accessible.

Methods inherited from class java.lang.Object

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

Method Detail

getFieldsInfo

public static <A> FieldInfoUtils.TypeInfoSchema getFieldsInfo(TypeInformation<A> inputType)

Returns a FieldInfoUtils.TypeInfoSchema for a given TypeInformation.

Type Parameters:

A - The type of the TypeInformation.

Parameters:

inputType - The TypeInformation to extract the mapping from.

Returns:

A description of the input that enables creation of a TableSchema.

See Also:

FieldInfoUtils.TypeInfoSchema

getFieldsInfo

public static <A> FieldInfoUtils.TypeInfoSchema getFieldsInfo(TypeInformation<A> inputType,
                                                              Expression[] expressions)

Returns a FieldInfoUtils.TypeInfoSchema for a given TypeInformation. It gives control of the process of mapping TypeInformation to TableSchema (via FieldInfoUtils.TypeInfoSchema).

Possible operations via the expressions include:

• specifying rowtime & proctime attributes via .proctime, .rowtime
  • There can be only a single rowtime and/or a single proctime attribute
  • Proctime attribute can only be appended to the end of the expression list
  • Rowtime attribute can replace an input field if the input field has a compatible type. See TimestampType.
• renaming fields by position (this cannot be mixed with referencing by name)
• renaming & projecting fields by name (this cannot be mixed with referencing by position)

Type Parameters:

A - The type of the TypeInformation.

Parameters:

inputType - The TypeInformation to extract the mapping from.

expressions - Expressions to apply while extracting the mapping.

Returns:

A description of the input that enables creation of a TableSchema.

See Also:

FieldInfoUtils.TypeInfoSchema

getFieldNames

public static <A> String[] getFieldNames(TypeInformation<A> inputType)

Returns field names for a given TypeInformation.

Type Parameters:

A - The type of the TypeInformation.

Parameters:

inputType - The TypeInformation extract the field names.

Returns:

An array holding the field names

getFieldNames

public static <A> String[] getFieldNames(TypeInformation<A> inputType,
                                         List<String> existingNames)

Returns field names for a given TypeInformation. If the input TypeInformation is not a composite type, the result field name should not exist in the existingNames.

Type Parameters:

A - The type of the TypeInformation.

Parameters:

inputType - The TypeInformation extract the field names.

existingNames - The existing field names for non-composite types that can not be used.

Returns:

An array holding the field names

validateInputTypeInfo

public static <A> void validateInputTypeInfo(TypeInformation<A> typeInfo)

Validate if class represented by the typeInfo is static and globally accessible.

Parameters:

typeInfo - type to check

Throws:

ValidationException - if type does not meet these criteria

getFieldIndices

public static int[] getFieldIndices(TypeInformation<?> inputType)

Returns field indexes for a given TypeInformation.

Parameters:

inputType - The TypeInformation extract the field positions from.

Returns:

An array holding the field positions

getFieldTypes

public static TypeInformation<?>[] getFieldTypes(TypeInformation<?> inputType)

Returns field types for a given TypeInformation.

Parameters:

inputType - The TypeInformation to extract field types from.

Returns:

An array holding the field types.