- Type Parameters:
T
- The database type - i.e. any type available fromSQLDataType
U
- The user type
- All Superinterfaces:
Serializable
- All Known Implementing Classes:
AbstractConverter
,Converters
,DateToLocalDateConverter
,DelegatingConverter
,EnumConverter
,IdentityConverter
,JPAConverter
,TimestampToLocalDateTimeConverter
,TimeToLocalTimeConverter
,XMLtoJAXBConverter
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))
, thenX.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
- Author:
- Lukas Eder
-
Method Summary
Modifier and TypeMethodDescriptionChain a converter to this converter.Turn this converter into a converter for arrays.static <T,
U> @NotNull Converter<T, U> Construct a new read-only converter from a function.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.fromType()
The database type.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> Construct a new write-only converter from a function.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.toType()
The user type.
-
Method Details
-
from
Read and convert a database object to a user object.- Parameters:
databaseObject
- The database object.- Returns:
- The user object.
-
to
Convert and write a user object to a database object.- Parameters:
userObject
- The user object.- Returns:
- The database object.
-
fromType
The database type. -
toType
The user type. -
inverse
Inverse this converter. -
andThen
Chain a converter to this converter. -
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:
-
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 typeU
- the user type- Parameters:
fromType
- The database typetoType
- The user typefrom
- 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:
-
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 typeU
- the user type- Parameters:
fromType
- The database typetoType
- The user typefrom
- 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:
-
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 conversionFunction
s are decorated with a function that always returnsnull
fornull
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 typeU
- the user type- Parameters:
fromType
- The database typetoType
- The user typefrom
- 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:
-
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 conversionFunction
is decorated with a function that always returnsnull
fornull
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:
-
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 conversionFunction
is decorated with a function that always returnsnull
fornull
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 typeU
- the user type- Parameters:
fromType
- The database typetoType
- The user typeto
- A function converting from U to T when writing to the database.- Returns:
- The converter.
- See Also:
-