jOOQ 3.18.7 · org.jooq.Converter

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

Irrespective of the Converter's encoding of null values above, an implementation must be able to handle null values.

Creating user defined `DataType`s

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

Method Summary

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

Method Detail

andThen	back to summary
public default <X> @NotNull Converter<T, X> andThen(Converter<? super U, X> converter) Chain a converter to this converter. Annotations @NotNull

andThen

back to summary

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

Chain a converter to this converter.

Annotations

@NotNull

forArrays	back to summary
public default @NotNull Converter<T[], U[]> forArrays() Turn this converter into a converter for arrays. Annotations @NotNull

forArrays

back to summary

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

Turn this converter into a converter for arrays.

Annotations

@NotNull

from	back to summary
public U from(T databaseObject) Read and convert a database object to a user object. Parameters databaseObject:T The database object. Returns:U The user object.

from

back to summary

public U from(T databaseObject)

Read and convert a database object to a user object.

Parameters

databaseObject:T: The database object.

Returns:U

The user object.

from back to summary

from	back to summary
public 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. Parameters <T> the database type <U> the user type fromType:Class<T> The database type toType:Class<U> The user type from:Function<? super T, ? extends U> A function converting from T to U when reading from the database. Returns:@NotNull Converter<T, U> The converter. Annotations @NotNull See Also `Converter`

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

Construct a new read-only converter from a function.

Parameters

<T>: the database type
: the user type
fromType:Class<T>: The database type
toType:Class: The user type
from:Function<? super T, ? extends U>: A function converting from T to U when reading from the database.

Returns:@NotNull Converter<T, U>

The converter.

Annotations

@NotNull

See Also

Converter

fromNullable back to summary

fromNullable	back to summary
public 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 `Converter#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));` Parameters <T> the database type. <U> the user type. fromType:Class<T> The database type. toType:Class<U> The user type. from:Function<? super T, ? extends U> A function converting from T to U when reading from the database. Returns:@NotNull Converter<T, U> The converter. Annotations @NotNull See Also `Converter`

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

Construct a new read-only converter from a function.

This works like Converter#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));

Parameters

<T>: the database type.
: the user type.
fromType:Class<T>: The database type.
toType:Class: The user type.
from:Function<? super T, ? extends U>: A function converting from T to U when reading from the database.

Returns:@NotNull Converter<T, U>

The converter.

Annotations

@NotNull

See Also

Converter

fromType	back to summary
public @NotNull Class<T> fromType() The database type. Annotations @NotNull

fromType

back to summary

public @NotNull Class<T> fromType()

The database type.

Annotations

@NotNull

inverse	back to summary
public default @NotNull Converter<U, T> inverse() Inverse this converter. Annotations @NotNull

inverse

back to summary

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

Inverse this converter.

Annotations

@NotNull

of back to summary

of	back to summary
public 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. Parameters <T> the database type. <U> the user type. fromType:Class<T> The database type. toType:Class<U> The user type. from:Function<? super T, ? extends U> A function converting from T to U when reading from the database. to:Function<? super U, ? extends T> A function converting from U to T when writing to the database. Returns:@NotNull Converter<T, U> The converter. Annotations @NotNull See Also `Converter`

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

Construct a new converter from functions.

Parameters

<T>: the database type.
: the user type.
fromType:Class<T>: The database type.
toType:Class: The user type.
from:Function<? super T, ? extends U>: A function converting from T to U when reading from the database.
to:Function<? super U, ? extends T>: A function converting from U to T when writing to the database.

Returns:@NotNull Converter<T, U>

The converter.

Annotations

@NotNull

See Also

Converter

ofNullable back to summary

ofNullable	back to summary
public 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 `Converter#of(Class, Class, Function, Function)`, except that both conversion `Function`s 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));` Parameters <T> the database type <U> the user type fromType:Class<T> The database type toType:Class<U> The user type from:Function<? super T, ? extends U> A function converting from T to U when reading from the database. to:Function<? super U, ? extends T> A function converting from U to T when writing to the database. Returns:@NotNull Converter<T, U> The converter. Annotations @NotNull See Also `Converter`

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

Construct a new converter from functions.

This works like Converter#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));

Parameters

<T>: the database type
: the user type
fromType:Class<T>: The database type
toType:Class: The user type
from:Function<? super T, ? extends U>: A function converting from T to U when reading from the database.
to:Function<? super U, ? extends T>: A function converting from U to T when writing to the database.

Returns:@NotNull Converter<T, U>

The converter.

Annotations

@NotNull

See Also

Converter

to	back to summary
public T to(U userObject) Convert and write a user object to a database object. Parameters userObject:U The user object. Returns:T The database object.

back to summary

public T to(U userObject)

Convert and write a user object to a database object.

Parameters

userObject:U: The user object.

Returns:T

The database object.

to back to summary

to	back to summary
public 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. Parameters <T> the database type <U> the user type fromType:Class<T> The database type toType:Class<U> The user type to:Function<? super U, ? extends T> A function converting from U to T when writing to the database. Returns:@NotNull Converter<T, U> The converter. Annotations @NotNull See Also `Converter`

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

Construct a new write-only converter from a function.

Parameters

<T>: the database type
: the user type
fromType:Class<T>: The database type
toType:Class: The user type
to:Function<? super U, ? extends T>: A function converting from U to T when writing to the database.

Returns:@NotNull Converter<T, U>

The converter.

Annotations

@NotNull

See Also

Converter

toNullable back to summary

toNullable	back to summary
public 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 `Converter#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));` Parameters <T> the database type <U> the user type fromType:Class<T> The database type toType:Class<U> The user type to:Function<? super U, ? extends T> A function converting from U to T when writing to the database. Returns:@NotNull Converter<T, U> The converter. Annotations @NotNull See Also `Converter`

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

Construct a new write-only converter from a function.

This works like Converter#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));

Parameters

<T>: the database type
: the user type
fromType:Class<T>: The database type
toType:Class: The user type
to:Function<? super U, ? extends T>: A function converting from U to T when writing to the database.

Returns:@NotNull Converter<T, U>