Package net.solarnetwork.central.domain

Interface CompositeKey

All Known Subinterfaces:
CompositeKey2<K1,K2>, CompositeKey3<K1,K2,K3>
All Known Implementing Classes:
LongIntegerCompositePK, LongStringCompositePK, UserLongCompositePK, UserLongIntegerCompositePK, UserLongStringCompositePK, UserStringCompositePK, UserUuidIntegerCompositePK, UserUuidLongCompositePK, UserUuidPK
public interface CompositeKey
API for a composite key.

  • Method Details

    • keyComponentLength

      int keyComponentLength()
      Get the number of components in the composite key.
      Returns:
      the number of components

    • keyComponentIsAssigned

      boolean keyComponentIsAssigned(int index)
      Test if a given key component is assigned a value or not.

      This method is designed to support cases when the key component is generated by an external system (such as a database) but the value is not allowed to be null. In this situation a placeholder value representing "not a value" can be used, and this method should return false if that value has been set on the instance.

      Parameters:
      index - the component index to test, starting from 0
      Returns:
      true if the key component's value should be considered "assigned", false otherwise

    • keyComponent

      Object keyComponent(int index)
      Get the key component for a specific index.
      Parameters:
      index - the index of the key component to get, starting from 0
      Returns:
      the associated key component, or null if the component is not assigned, or the index is out of range

    • keyComponentValue

      <T> T keyComponentValue(int index, Object val)
      Convert a value into a key component value.
      Type Parameters:
      T - the expected key component type
      Parameters:
      index - the index of the key component to convert the value for
      val - the value to convert, or null to use an "unassigned" value
      Returns:
      the key component value
      Throws:
      IllegalArgumentException - if val is not a supported type, or index is out of range of the key component length
      Since:
      1.2

    • createKey

      CompositeKey createKey(CompositeKey template, Object... components)
      Create a new key instance based on a template and component arguments.

      If less component values are provided than the length of the given key type, then "unassigned" values will be used for those components.

      Parameters:
      template - the template key, or the implementation may support null to create a new key from scratch, or else UnsupportedOperationException will be thrown
      components - the component values to use
      Returns:
      the new key instance
      Throws:
      IllegalArgumentException - if the component values are not appropriate for the key type
      Since:
      1.2