Module org.postgresql.pljava
Package org.postgresql.pljava.annotation

Annotation Type Cast

  • @Documented
@Target({METHOD,TYPE})
@Repeatable(Container.class)
@Retention(CLASS)
public @interface Cast
    Declares a PostgreSQL CAST.

    May annotate a Java method (which should also carry a @Function annotation, making it a PostgreSQL function), or a class or interface (just to have a place to put it when not directly associated with a method).

    If not applied to a method, must supply path= specifying BINARY or INOUT.

    The source and target types must be specified with from and to, unless the annotation appears on a method, in which case these default to the first parameter and return types of the function, respectively.

    The cast will, by default, have to be applied explicitly, unless application=ASSIGNMENT or application=IMPLICIT is given.

    Author:
    Chapman Flack

    • Optional Element Summary

      Optional Elements 
      Modifier and Type Optional Element Description
      Cast.Application application
      When this cast can be applied: only in explicit form, when used in assignment context, or implicitly whenever needed.
      String comment
      A comment to be associated with the cast.
      String from
      The source type to be cast.
      String implementor
      The <implementor name> to be used around SQL code generated for this cast.
      Cast.Path path
      A stock conversion path when a dedicated function is not supplied: BINARY for two types that are known to have the same internal representation, or INOUT to invoke the first type's text-output function followed by the second type's text-input function.
      String[] provides
      One or more arbitrary labels that will be considered 'provided' by the object carrying this annotation.
      String[] requires
      One or more arbitrary labels that will be considered 'required' by the object carrying this annotation.
      String to
      The target type to cast to.

    • Element Detail

      • from

        String from
        The source type to be cast. Will default to the first parameter type of the associated function, if known.

        PostgreSQL will allow this type and the function's first parameter type to differ, if there is an existing binary cast between them. That cannot be checked at compile time, so a cast with a different type given here might successfully compile but fail to deploy in PostgreSQL.

        Default:
        ""

      • to

        String to
        The target type to cast to. Will default to the return type of the associated function, if known.

        PostgreSQL will allow this type and the function's return type to differ, if there is an existing binary cast between them. That cannot be checked at compile time, so a cast with a different type given here might successfully compile but fail to deploy in PostgreSQL.

        Default:
        ""

      • path

        Cast.Path path
        A stock conversion path when a dedicated function is not supplied: BINARY for two types that are known to have the same internal representation, or INOUT to invoke the first type's text-output function followed by the second type's text-input function.

        To declare an INOUT cast, with=INOUT must appear explicitly; the default value is treated as unspecified.

        Default:
        org.postgresql.pljava.annotation.Cast.Path.INOUT

      • application

        Cast.Application application
        When this cast can be applied: only in explicit form, when used in assignment context, or implicitly whenever needed.
        Default:
        org.postgresql.pljava.annotation.Cast.Application.EXPLICIT

      • provides

        String[] provides
        One or more arbitrary labels that will be considered 'provided' by the object carrying this annotation. The deployment descriptor will be generated in such an order that other objects that 'require' labels 'provided' by this come later in the output for install actions, and earlier for remove actions.
        Default:
        {}

      • requires

        String[] requires
        One or more arbitrary labels that will be considered 'required' by the object carrying this annotation. The deployment descriptor will be generated in such an order that other objects that 'provide' labels 'required' by this come earlier in the output for install actions, and later for remove actions.
        Default:
        {}

      • implementor

        String implementor
        The <implementor name> to be used around SQL code generated for this cast. Defaults to PostgreSQL. Set explicitly to "" to emit code not wrapped in an <implementor block>.
        Default:
        ""

      • comment

        String comment
        A comment to be associated with the cast. If left to default, and the annotated Java construct has a doc comment, its first sentence will be used. If an empty string is explicitly given, no comment will be set.
        Default:
        ""