Hibernate understands both the Java and JDBC representations of application data. The ability to read and write object data to a database are called marshalling, and is the function of a Hibernate type
. A is A type
implementation of the org.hibernate.type.Type
interface. A Hibernate type
describes various aspects of behavior of the Java type such as how to check for equality and what to Clon E values.
Usage of the word
type
A Hibernate is type
neither a Java type nor a SQL datatype. It provides information about both of these.
When you encounter the term type in regards to Hibernate, it could refer to the Java type, the JDBC type, or the Hi Bernate type, depending on context.
1. Value types1.1. Basic types
Basic value types usually map a single database value, or column, to a single, non-aggregated Java type. Hibernate provides a number of built-in basic types, which follow the natural mappings recommended in the JDBC Specificati Ons. You can override these mappings and provide and use alternative mappings. These topics is discussed further on.
Table 1.1. Basic Type Mappings
Hibernate Type |
Database Type |
JDBC Type |
Type Registry |
Org.hibernate.type.StringType |
String |
VARCHAR |
String, java.lang.String |
Org.hibernate.type.MaterializedClob |
String |
Clob |
Materialized_clob |
Org.hibernate.type.TextType |
String |
LongVarChar |
Text |
Org.hibernate.type.CharacterType |
Char, Java.lang.Character |
CHAR |
Char, Java.lang.Character |
Org.hibernate.type.BooleanType |
Boolean |
BIT |
Boolean, Java.lang.Boolean |
Org.hibernate.type.NumericBooleanType |
Boolean |
INTEGER, 0 is False, 1 is true |
Numeric_boolean |
Org.hibernate.type.YesNoType |
Boolean |
CHAR, ' n '/' n ' is false, ' y '/' y ' is true. The uppercase value is written to the database. |
Yes_no |
Org.hibernate.type.TrueFalseType |
Boolean |
CHAR, ' F '/' F ' is false, ' t '/' is true. The uppercase value is written to the database. |
True_false |
Org.hibernate.type.ByteType |
BYTE, Java.lang.Byte |
TINYINT |
BYTE, Java.lang.Byte |
Org.hibernate.type.ShortType |
Short, Java.lang.Short |
SMALLINT |
Short, Java.lang.Short |
Org.hibernate.type.IntegerTypes |
int, Java.lang.Integer |
INTEGER |
int, Java.lang.Integer |
Org.hibernate.type.LongType |
Long, Java.lang.Long |
BIGINT |
Long, Java.lang.Long |
Org.hibernate.type.FloatType |
float, java.lang.Float |
FLOAT |
float, java.lang.Float |
Org.hibernate.type.DoubleType |
Double, java.lang.Double |
DOUBLE |
Double, java.lang.Double |
Org.hibernate.type.BigIntegerType |
Java.math.BigInteger |
NUMERIC |
Big_integer |
Org.hibernate.type.BigDecimalType |
Java.math.BigDecimal |
NUMERIC |
Big_decimal, Java.math.bigDecimal |
Org.hibernate.type.TimestampType |
Java.sql.Timestamp |
TIMESTAMP |
Timestamp, Java.sql.Timestamp |
Org.hibernate.type.TimeType |
Java.sql.Time |
Time |
Time, Java.sql.Time |
Org.hibernate.type.DateType |
Java.sql.Date |
DATE |
Date, Java.sql.Date |
Org.hibernate.type.CalendarType |
Java.util.Calendar |
TIMESTAMP |
Calendar, Java.util.Calendar |
Org.hibernate.type.CalendarDateType |
Java.util.Calendar |
DATE |
Calendar_date |
Org.hibernate.type.CurrencyType |
Java.util.Currency |
VARCHAR |
Currency, java.util.Currency |
Org.hibernate.type.LocaleType |
Java.util.Locale |
VARCHAR |
Locale, Java.utility.locale |
Org.hibernate.type.TimeZoneType |
Java.util.TimeZone |
VARCHAR, using the TimeZone ID |
TimeZone, Java.util.TimeZone |
Org.hibernate.type.UrlType |
Java.net.URL |
VARCHAR |
URL, Java.net.URL |
Org.hibernate.type.ClassType |
Java.lang.Class |
VARCHAR, using the class name |
Class, Java.lang.Class |
Org.hibernate.type.BlobType |
Java.sql.Blob |
Blob |
Blog, Java.sql.Blob |
Org.hibernate.type.ClobType |
Java.sql.Clob |
Clob |
CLOB, Java.sql.Clob |
Org.hibernate.type.BinaryType |
Primitive byte[] |
VARBINARY |
Binary, byte[] |
Org.hibernate.type.MaterializedBlobType |
Primitive byte[] |
Blob |
Materized_blob |
Org.hibernate.type.ImageType |
Primitive byte[] |
LongVarBinary |
Image |
Org.hibernate.type.BinaryType |
Java.lang.byte[] |
VARBINARY |
Wrapper-binary |
Org.hibernate.type.CharArrayType |
Char[] |
VARCHAR |
Characters, char[] |
Org.hibernate.type.CharacterArrayType |
Java.lang.character[] |
VARCHAR |
Wrapper-characters, character[], java.lang.character[] |
Org.hibernate.type.UUIDBinaryType |
Java.util.UUID |
BINARY |
Uuid-binary, Java.util.UUID |
Org.hibernate.type.UUIDCharType |
Java.util.UUID |
CHAR, can also read VARCHAR |
Uuid-char |
Org.hibernate.type.PostgresUUIDType |
Java.util.UUID |
PostgreSQL UUID, through Types#other, which complies to the PostgreSQL JDBC driver definition |
Pg-uuid |
Org.hibernate.type.SerializableType |
Implementors of Java.lang.Serializable |
VARBINARY |
Unlike the other value types, multiple instances of this type is registered. It is registered once under Java.io.Serializable, and registered under the specific Java.io.Serializable implementation CL The names. |
1.2. National Character Types
National Character types, which are a new feature since JDBC 4.0 API, now available in Hibernate type System. National Language support enables you retrieve data or insert data to a database in any character set that the Underlyin G Database supports.
Depending on your environment, you might want to set the configuration option Hibernate.use_nationalized_character_dat A to true and have all string or CLOB based attributes have this national character support automatically. There is nothing else to being changed, and you don ' t has to use any hibernate specific mapping, so it's portable (though The national character support feature are not required, and may not be work on other JPA provider Impl).
The other-to-be-the-feature is has the annotation on the @Nationalized
attribute that should be nationalized. This is only works on string based attributes, including string, char, char array and CLOB.
@Entity (name= "nationalizedentity") public static class Nationalizedentity { @Id private Integer Id; @Nationalized private String Nvarcharatt; @Lob @Nationalized private String Materializednclobatt; @Lob @Nationalized private NClob Nclobatt; @Nationalized private Character Ncharacteratt; @Nationalized private character[] Nchararratt; @Type (Type = "ntext") private String Nlongvarcharcharatt; }
Table 1.2. National Character Type Mappings
Hibernate type |
Database type |
JDBC type |
type registry |
Org.hibernate.type.StringNVarcharType |
String |
NVARCHAR |
Nstring |
Org.hibernate.type.NTextType |
String |
Longnvarchar |
Materialized_clob |
Org.hibernate.type.NClobType |
Java.sql.NClob |
NCLOB |
Nclob |
Org.hibernate.type.MaterializedNClobType |
String |
NCLOB |
Materialized_nclob |
Org.hibernate.type.PrimitiveCharacterArrayNClobType |
Char[] |
NCHAR |
Char[] |
Org.hibernate.type.CharacterNCharType |
Java.lang.Character |
NCHAR |
Ncharacter |
Org.hibernate.type.CharacterArrayNClobType |
Java.lang.character[] |
NCLOB |
Character[], java.lang.character[] |
1.3. Composite types
Composite types, or embedded types, as they is called by the Java persistence API, with traditionally b Een called in Hibernate. All of these terms mean the same thing.
Components represent aggregations of values to a single Java type. An example Address
is a class, which aggregates street, city, state, and postal code. A composite type behaves in a similar-to-an entity. They is each classes written specifically for an application. They may both include references to other application-specific classes, as-well-to-collections and simple JDK types. The only distinguishing factors is, a component does not having its own lifecycle or define an identifier.
1.4. Collection types
A collection type refers to the data type itself, not its contents.
A Collection denotes a one-to-one or one-to-many relationship between tables of a database.
Refer to the chapter in collections for more information on collections.
2. Entity Types
Entities is application-specific classes which correlate to rows in a table, using a unique identifier. Because of the requirement for a unique identifier, ntities exist independently and define their own lifecycle. As an example, deleting a membership should not delete the User or the Group. For more information, see the chapter on persistent Classes.
From Hibernate official website
Hibernate Object Mapping Type