Record Class StructType

java.lang.Object

java.lang.Record

smile.data.type.StructType

Record Components:

fields - The struct fields.

index - The map of field name to index.

All Implemented Interfaces:

Serializable, DataType

public record StructType(List<StructField> fields, Map<String,Integer> index)
extends Record
implements DataType

Struct data type is determined by the fixed order of the fields of primitive data types in the struct. An instance of a struct type will be a tuple.

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface DataType

DataType.ID

Constructor Summary

Constructors

Constructor	Description
StructType(List<StructField> fields)	Constructor.
StructType(List<StructField> fields, Map<String,Integer> index)	Creates an instance of a StructType record class.
StructType(StructField... fields)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	add(StructField field)	Adds a field.
StructField	apply(int i)	Return the i-th field.
StructField	apply(String name)	Return the field of given name.
DataType[]	dtypes()	Returns the field data types.
boolean	equals(Object o)	Indicates whether some other object is "equal to" this one.
StructField	field(int i)	Return the i-th field.
StructField	field(String name)	Return the field of given name.
List<StructField>	fields()	Returns the value of the fields record component.
final int	hashCode()	Returns a hash code value for this object.
DataType.ID	id()	Returns the type ID enum.
Map<String,Integer>	index()	Returns the value of the index record component.
int	indexOf(String field)	Returns the ordinal index of a field.
int	length()	Returns the number of fields.
Measure[]	measures()	Returns the field's level of measurements.
String	name()	Returns the type name used in external catalogs.
String[]	names()	Returns the field names.
static StructType	of(Class<?> clazz)	Returns the struct type of record or bean class.
static StructType	of(ResultSet rs)	Returns a struct data type from JDBC result set meta data.
static StructType	of(ResultSetMetaData meta, String dbms)	Returns a struct data type from JDBC result set meta data.
static StructType	of(Property[] props)	Returns the struct type of record or bean class properties.
static StructType	of(ValueVector... columns)	Returns the schema of a set of columns.
List<Function<String,Object>>	parser()	Returns the lambda functions that parse field values.
void	rename(String name, String newName)	Renames a field.
void	set(int i, StructField field)	Sets a field.
String	toString()	Returns a string representation of this record class.
String	toString(Object o)	Returns the string representation of a value of the type.
void	update(int i, StructField field)	Sets a field.
Tuple	valueOf(String s)	Returns the value from its string representation.

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface DataType

isBoolean, isByte, isChar, isDecimal, isDouble, isFloat, isFloating, isInt, isIntegral, isLong, isNullable, isNumeric, isObject, isPrimitive, isShort, isString

Constructor Details

StructType

public StructType(List<StructField> fields)

Constructor.

Parameters:

fields - the struct fields.

StructType

public StructType(StructField... fields)

Constructor.

Parameters:

fields - the struct fields.

StructType

public StructType(List<StructField> fields,
 Map<String,Integer> index)

Creates an instance of a StructType record class.

Parameters:

fields - the value for the fields record component

index - the value for the index record component

Method Details

of

public static StructType of(ValueVector... columns)

Returns the schema of a set of columns.

Parameters:

columns - the columns to form a data frame.

Returns:

the schema.

length

public int length()

Returns the number of fields.

Returns:

the number of fields.

field

public StructField field(int i)

Return the i-th field.

Parameters:

i - the field index.

Returns:

the field.

field

public StructField field(String name)

Return the field of given name.

Parameters:

name - the field name.

Returns:

the field.

apply

public StructField apply(int i)

Return the i-th field. This is an alias to field for Scala's convenience.

Parameters:

i - the field index.

Returns:

the field.

apply

public StructField apply(String name)

Return the field of given name. This is an alias to field for Scala's convenience.

Parameters:

name - the field name.

Returns:

the field.

set

public void set(int i,
 StructField field)

Sets a field.

Parameters:

i - the field index.

field - the new field.

update

public void update(int i,
 StructField field)

Sets a field. This is an alias to set for Scala's convenience.

Parameters:

i - the field index.

field - the new field.

rename

public void rename(String name,
 String newName)

Renames a field.

Parameters:

name - the field name.

newName - the new name.

add

public void add(StructField field)

Adds a field.

Parameters:

field - a struct field.

indexOf

public int indexOf(String field)

Returns the ordinal index of a field.

Parameters:

field - the field name.

Returns:

the index of field.

names

public String[] names()

Returns the field names.

Returns:

the field names.

dtypes

public DataType[] dtypes()

Returns the field data types.

Returns:

the field data types.

measures

public Measure[] measures()

Returns the field's level of measurements.

Returns:

the field's level of measurements.

parser

public List<Function<String,Object>> parser()

Returns the lambda functions that parse field values.

Returns:

the lambda functions that parse field values.

name

public String name()

Description copied from interface: DataType

Returns the type name used in external catalogs. DataType.of(name()) should return the same type.

Specified by:

name in interface DataType

Returns:

the type name used in external catalogs.

id

public DataType.ID id()

Description copied from interface: DataType

Returns the type ID enum.

Specified by:

id in interface DataType

Returns:

the type ID enum.

toString

public String toString()

Returns a string representation of this record class. The representation contains the name of the class, followed by the name and value of each of the record components.

Specified by:

toString in class Record

Returns:

a string representation of this object

toString

public String toString(Object o)

Description copied from interface: DataType

Returns the string representation of a value of the type.

Specified by:

toString in interface DataType

Parameters:

o - the value.

Returns:

the string representation

valueOf

public Tuple valueOf(String s)

Description copied from interface: DataType

Returns the value from its string representation.

Specified by:

valueOf in interface DataType

Parameters:

s - the string representation of a value of this type.

Returns:

the value.

equals

public boolean equals(Object o)

Indicates whether some other object is "equal to" this one. The objects are equal if the other object is of the same class and if all the record components are equal. All components in this record class are compared with Objects::equals(Object,Object).

Specified by:

equals in class Record

Parameters:

o - the object with which to compare

Returns:

true if this object is the same as the o argument; false otherwise.

of

public static StructType of(Class<?> clazz)

Returns the struct type of record or bean class.

Parameters:

clazz - the class type of elements.

Returns:

the struct type.

of

public static StructType of(Property[] props)

Returns the struct type of record or bean class properties.

Parameters:

props - the record or bean class properties.

Returns:

the struct type.

of

public static StructType of(ResultSet rs)
                     throws SQLException

Returns a struct data type from JDBC result set meta data.

Parameters:

rs - the JDBC result set.

Returns:

the struct data type.

Throws:

SQLException - when JDBC operation fails.

of

public static StructType of(ResultSetMetaData meta,
 String dbms)
                     throws SQLException

Returns a struct data type from JDBC result set meta data.

Parameters:

meta - the JDBC result set meta data.

dbms - the name of database management system.

Returns:

the struct data type.

Throws:

SQLException - when JDBC operation fails.

hashCode

public final int hashCode()

Returns a hash code value for this object. The value is derived from the hash code of each of the record components.

Specified by:

hashCode in class Record

Returns:

a hash code value for this object

fields

public List<StructField> fields()

Returns the value of the fields record component.

Returns:

the value of the fields record component

index

public Map<String,Integer> index()

Returns the value of the index record component.

Returns:

the value of the index record component