Package com.blazebit.persistence.spi

Interface JpqlFunction

public interface JpqlFunction
Interface for implementing a JPA custom function that renders dbms specific code. An instance of this interface needs to be registered to be able to use the function in queries.
Since:
1.0.0
Author:
Christian Beikov
See Also:
EntityManagerFactoryIntegrator.registerFunctions(javax.persistence.EntityManagerFactory, java.util.Map)

  • Method Summary

    Modifier and Type Method Description
    Class<?> getReturnType​(Class<?> firstArgumentType)
    Returns the return type of this function.
    boolean hasArguments()
    Returns true if the function has arguments, false otherwise.
    boolean hasParenthesesIfNoArguments()
    Returns false if parentheses might be skipped if no arguments are given, true otherwise.
    void render​(FunctionRenderContext context)
    Renders the function into the given function render context.

  • Method Details

    • hasArguments

      boolean hasArguments()
      Returns true if the function has arguments, false otherwise.
      Returns:
      true if the function has arguments, false otherwise

    • hasParenthesesIfNoArguments

      boolean hasParenthesesIfNoArguments()
      Returns false if parentheses might be skipped if no arguments are given, true otherwise.
      Returns:
      false if parentheses might be skipped if no arguments are given, true otherwise

    • getReturnType

      Class<?> getReturnType​(Class<?> firstArgumentType)
      Returns the return type of this function. The return type may be null, but beware that nesting this function into other expressions may then fail.
      Parameters:
      firstArgumentType - The type of the first argument
      Returns:
      the return type of this function, or null

    • render

      void render​(FunctionRenderContext context)
      Renders the function into the given function render context.
      Parameters:
      context - The context into which the function should be rendered