Package name.martingeisse.grumpyjson.builtin.helper_types

Record Class FieldMustBeNull

java.lang.Object
java.lang.Record
name.martingeisse.grumpyjson.builtin.helper_types.FieldMustBeNull
public record FieldMustBeNull() extends Record
This can be used to implement a property that must be JSON-null during deserialziation, and always serializes as JSON-null. Such a property obviously does not add any information to the data structure, but might be useful to maintain compatibility with a field that was used in previous versions.

This class can be wrapped in OptionalField to allow the field to be absent or null, as well as control whether the field gets serialized as absent or null.

A shared instance is provided to reduce memory usage, but creating new instances is fine as well.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final FieldMustBeNull
    INSTANCE
    The shared instance of this class.

  • Constructor Summary

    Constructors
    Constructor
    Description
    FieldMustBeNull()
    Creates an instance of a FieldMustBeNull record class.

  • Method Summary

    Modifier and Type
    Method
    Description
    final boolean
    equals(Object o)
    Indicates whether some other object is "equal to" this one.
    final int
    hashCode()
    Returns a hash code value for this object.
    final String
    toString()
    Returns a string representation of this record class.

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Field Details

    • INSTANCE

      public static final FieldMustBeNull INSTANCE
      The shared instance of this class. Can be used to avoid memory usage from creating a new instance. This is not a singleton because it is possible to create other instances.

  • Constructor Details

    • FieldMustBeNull

      public FieldMustBeNull()
      Creates an instance of a FieldMustBeNull record class.

  • Method Details

    • toString

      public final String toString()
      Returns a string representation of this record class. The representation contains the name of the class, followed by the name and value of each of the record components.
      Specified by:
      toString in class Record
      Returns:
      a string representation of this object

    • hashCode

      public final int hashCode()
      Returns a hash code value for this object. The value is derived from the hash code of each of the record components.
      Specified by:
      hashCode in class Record
      Returns:
      a hash code value for this object

    • equals

      public final boolean equals(Object o)
      Indicates whether some other object is "equal to" this one. The objects are equal if the other object is of the same class and if all the record components are equal.
      Specified by:
      equals in class Record
      Parameters:
      o - the object with which to compare
      Returns:
      true if this object is the same as the o argument; false otherwise.