Type Parameters:

T - The database type - i.e. any type available from SQLDataType

U - The user type

All Superinterfaces:

Serializable

All Known Implementing Classes:

AbstractConverter, Converters, DateToLocalDateConverter, DelegatingConverter, EnumConverter, IdentityConverter, JPAConverter, TimestampToLocalDateTimeConverter, TimeToLocalTimeConverter
```
public interface Converter<T,U>
extends Serializable
```
A Converter for data types.
A general data type conversion interface that can be provided to jOOQ at various places in order to perform custom data type conversion. Conversion is directed, this means that the Converter is used
- to load database types converting them to user types "FROM" the database. Hence, fromType() is the type as defined in the database. Think of "FROM" = "reading".
- to store user types converting them to database types "TO" the database. Think of "TO" = "writing". Hence, toType() is the user-defined type
Note: In order to avoid unwanted side-effects, it is highly recommended (yet not required) for from(Object) and to(Object) to be reciprocal. The two methods are reciprocal, if for all X and Y, it can be said that
- if Y.equals(converter.from(X)), then X.equals(converter.to(Y)).
- X.equals(converter.from(converter.to(X)))
- X.equals(converter.to(converter.from(X)))
Furthermore, it is recommended (yet not required) that
- converter.from(null) == null
- converter.to(null) == null
Creating user defined DataTypes

jOOQ provides built in data types through SQLDataType. Users can define their own data types programmatically by calling DataType.asConvertedDataType(Converter) or DataType.asConvertedDataType(Binding), for example. Custom data types can also be defined on generated code using the <forcedType/> configuration, see the manual for more details
Author:

Lukas Eder

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default <X> @NotNull Converter<T,X>`	`andThen(Converter<? super U,X> converter)`	Chain a converter to this converter.
`default @NotNull Converter<T[],U[]>`	`forArrays()`	Turn this converter into a converter for arrays.
`static <T,U> @NotNull Converter<T,U>`	`from(Class<T> fromType, Class<U> toType, Function<? super T,? extends U> from)`	Construct a new read-only converter from a function.
`U`	`from(T databaseObject)`	Read and convert a database object to a user object.
`static <T,U> @NotNull Converter<T,U>`	`fromNullable(Class<T> fromType, Class<U> toType, Function<? super T,? extends U> from)`	Construct a new read-only converter from a function.
`@NotNull Class<T>`	`fromType()`	The database type.
`default @NotNull Converter<U,T>`	`inverse()`	Inverse this converter.
`static <T,U> @NotNull Converter<T,U>`	`of(Class<T> fromType, Class<U> toType, Function<? super T,? extends U> from, Function<? super U,? extends T> to)`	Construct a new converter from functions.
`static <T,U> @NotNull Converter<T,U>`	`ofNullable(Class<T> fromType, Class<U> toType, Function<? super T,? extends U> from, Function<? super U,? extends T> to)`	Construct a new converter from functions.
`static <T,U> @NotNull Converter<T,U>`	`to(Class<T> fromType, Class<U> toType, Function<? super U,? extends T> to)`	Construct a new write-only converter from a function.
`T`	`to(U userObject)`	Convert and write a user object to a database object.
`static <T,U> @NotNull Converter<T,U>`	`toNullable(Class<T> fromType, Class<U> toType, Function<? super U,? extends T> to)`	Construct a new write-only converter from a function.
`@NotNull Class<U>`	`toType()`	The user type.

Method Detail

from
```
U from(T databaseObject)
```
Read and convert a database object to a user object.

Parameters:

databaseObject - The database object.

Returns:

The user object.

to
```
T to(U userObject)
```
Convert and write a user object to a database object.

Parameters:

userObject - The user object.

Returns:

The database object.

fromType
```
@NotNull
@NotNull Class<T> fromType()
```
The database type.

toType
```
@NotNull
@NotNull Class<U> toType()
```
The user type.

inverse

@NotNull
default @NotNull Converter<U,T> inverse()

Inverse this converter.

andThen

@NotNull
default <X> @NotNull Converter<T,X> andThen(Converter<? super U,X> converter)

Chain a converter to this converter.

forArrays

@NotNull
default @NotNull Converter<T[],U[]> forArrays()

Turn this converter into a converter for arrays.

of

@NotNull
static <T,U> @NotNull Converter<T,U> of(Class<T> fromType,
                                                    Class<U> toType,
                                                    Function<? super T,? extends U> from,
                                                    Function<? super U,? extends T> to)

Construct a new converter from functions.

Type Parameters:: T - the database type.; U - the user type.
Parameters:: fromType - The database type.; toType - The user type.; from - A function converting from T to U when reading from the database.; to - A function converting from U to T when writing to the database.
Returns:: The converter.
See Also:: Converter

from

@NotNull
static <T,U> @NotNull Converter<T,U> from(Class<T> fromType,
                                                      Class<U> toType,
                                                      Function<? super T,? extends U> from)

Construct a new read-only converter from a function.

Type Parameters:: T - the database type; U - the user type
Parameters:: fromType - The database type; toType - The user type; from - A function converting from T to U when reading from the database.; to - A function converting from U to T when writing to the database.
Returns:: The converter.
See Also:: Converter

to
```
@NotNull
static <T,U> @NotNull Converter<T,U> to(Class<T> fromType,
                                                    Class<U> toType,
                                                    Function<? super U,? extends T> to)
```
Construct a new write-only converter from a function.

Type Parameters:

T - the database type

U - the user type

Parameters:

fromType - The database type

toType - The user type

from - A function converting from T to U when reading from the database.

to - A function converting from U to T when writing to the database.

Returns:

The converter.

See Also:

Converter

ofNullable

@NotNull
static <T,U> @NotNull Converter<T,U> ofNullable(Class<T> fromType,
                                                            Class<U> toType,
                                                            Function<? super T,? extends U> from,
                                                            Function<? super U,? extends T> to)

Construct a new converter from functions.

This works like of(Class, Class, Function, Function), except that both conversion Functions are decorated with a function that always returns null for null inputs.

Example:


 Converter<String, Integer> converter =
   Converter.ofNullable(String.class, Integer.class, Integer::parseInt, Object::toString);

 // No exceptions thrown
 assertNull(converter.from(null));
 assertNull(converter.to(null));

Type Parameters:: T - the database type; U - the user type
Parameters:: fromType - The database type; toType - The user type; from - A function converting from T to U when reading from the database.; to - A function converting from U to T when writing to the database.
Returns:: The converter.
See Also:: Converter

fromNullable

@NotNull
static <T,U> @NotNull Converter<T,U> fromNullable(Class<T> fromType,
                                                              Class<U> toType,
                                                              Function<? super T,? extends U> from)

Construct a new read-only converter from a function.

This works like from(Class, Class, Function), except that the conversion Function is decorated with a function that always returns null for null inputs.

Example:


 Converter<String, Integer> converter =
   Converter.fromNullable(String.class, Integer.class, Integer::parseInt);

 // No exceptions thrown
 assertNull(converter.from(null));

Type Parameters:: T - the database type.; U - the user type.
Parameters:: fromType - The database type.; toType - The user type.; from - A function converting from T to U when reading from the database.
Returns:: The converter.
See Also:: Converter

toNullable

@NotNull
static <T,U> @NotNull Converter<T,U> toNullable(Class<T> fromType,
                                                            Class<U> toType,
                                                            Function<? super U,? extends T> to)

Construct a new write-only converter from a function.

This works like to(Class, Class, Function), except that the conversion Function is decorated with a function that always returns null for null inputs.

Example:


 Converter<String, Integer> converter =
   Converter.toNullable(String.class, Integer.class, Object::toString);

 // No exceptions thrown
 assertNull(converter.to(null));

Type Parameters:: T - the database type; U - the user type
Parameters:: fromType - The database type; toType - The user type; to - A function converting from U to T when writing to the database.
Returns:: The converter.
See Also:: Converter

Interface Converter<T,U>

Creating user defined `DataType`s

Method Summary

Method Detail

from

to

fromType

toType

inverse

andThen

forArrays

of

from

to

ofNullable

fromNullable

toNullable

Interface Converter<T,​U>

Creating user defined DataTypes

Method Summary

Method Detail

from

to

fromType

toType

inverse

andThen

forArrays

of

from

to

ofNullable

fromNullable

toNullable

Interface Converter<T,U>

Creating user defined `DataType`s