Interface UserType<J>

  • All Known Subinterfaces:
    EnhancedUserType<J>, UserVersionType<T>
    All Known Implementing Classes:
    BaseUserTypeSupport, EnumType, RevisionTypeType, StaticUserTypeSupport, UserTypeLegacyBridge, UserTypeSupport

    public interface UserType<J>
    This interface should be implemented by user-defined "types". A "type" class is not the actual property type - it is a class that knows how to serialize instances of another class to and from JDBC.

    This interface

    • abstracts user code from future changes to the Type interface,
    • simplifies the implementation of custom types and
    • hides certain "internal" interfaces from user code.

    Implementors must be immutable and must declare a public default constructor.

    The actual class mapped by a UserType may be just about anything.

    CompositeUserType provides an extended version of this interface that is useful for more complex cases.

    Alternatively, custom types could implement Type directly or extend one of the abstract classes in org.hibernate.type. This approach risks future incompatible changes to classes or interfaces in that package.

    See Also:
    Type, CustomType
    • Method Detail

      • getSqlType

        int getSqlType()
        Return the SQL type code for the column mapped by this type. The codes are generally defined on org.hibernate.type.SqlTypes, but could be database-specific codes
        See Also:
      • returnedClass

        Class<J> returnedClass()
        The class returned by nullSafeGet().
      • equals

        boolean equals​(J x,
                       J y)
        Compare two instances of the class mapped by this type for persistence "equality". Equality of the persistent state.
      • hashCode

        int hashCode​(J x)
        Get a hashcode for the instance, consistent with persistence "equality"
      • deepCopy

        J deepCopy​(J value)
        Return a deep copy of the persistent state, stopping at entities and at collections. It is not necessary to copy immutable objects, or null values, in which case it is safe to simply return the argument.
        value - the object to be cloned, which may be null
        Object a copy
      • isMutable

        boolean isMutable()
        Are objects of this type mutable?
      • disassemble

        Serializable disassemble​(J value)
        Transform the object into its cacheable representation. At the very least this method should perform a deep copy if the type is mutable. That may not be enough for some implementations, however; for example, associations must be cached as identifier values. (optional operation)
        value - the object to be cached
        a cacheable representation of the object
      • assemble

        J assemble​(Serializable cached,
                   Object owner)
        Reconstruct an object from the cacheable representation. At the very least this method should perform a deep copy if the type is mutable. (optional operation)
        cached - the object to be cached
        owner - the owner of the cached object
        a reconstructed object from the cacheable representation
      • replace

        J replace​(J detached,
                  J managed,
                  Object owner)
        During merge, replace the existing (target) value in the entity we are merging to with a new (original) value from the detached entity we are merging. For immutable objects, or null values, it is safe to simply return the first parameter. For mutable objects, it is safe to return a copy of the first parameter. For objects with component values, it might make sense to recursively replace component values.
        detached - the value from the detached entity being merged
        managed - the value in the managed entity
        the value to be merged
      • getDefaultSqlLength

        default long getDefaultSqlLength​(Dialect dialect,
                                         JdbcType jdbcType)
      • getDefaultSqlPrecision

        default int getDefaultSqlPrecision​(Dialect dialect,
                                           JdbcType jdbcType)
      • getDefaultSqlScale

        default int getDefaultSqlScale​(Dialect dialect,
                                       JdbcType jdbcType)
      • getValueConverter

        default BasicValueConverter<J,​Object> getValueConverter()
        Returns the converter that this user type uses for transforming from the domain type, to the relational type, or null if there is no conversion. Note that it is vital to provide a converter if a column should be mapped to multiple domain types, as Hibernate will only select a column once and materialize values as JdbcMapping.getJdbcJavaType(). Support for multiple domain type representations works by converting objects of that type to the domain type.