Record Class

Definition

[Android.Runtime.Register("java/lang/Record", ApiSince=34, DoNotGenerateAcw=true)]
public abstract class Record : Java.Lang.Object

[<Android.Runtime.Register("java/lang/Record", ApiSince=34, DoNotGenerateAcw=true)>]
type Record = class
    inherit Object

Inheritance

Object

Object

Record

Attributes

RegisterAttribute

Remarks

This is the common base class of all Java language record classes.

More information about records, including descriptions of the implicitly declared methods synthesized by the compiler, can be found in section 8.10 of <cite>The Java Language Specification</cite>.

A <em>record class</em> is a shallowly immutable, transparent carrier for a fixed set of values, called the <em>record components</em>. The Java language provides concise syntax for declaring record classes, whereby the record components are declared in the record header. The list of record components declared in the record header form the <em>record descriptor</em>.

A record class has the following mandated members: a <em>canonical constructor</em>, which must provide at least as much access as the record class and whose descriptor is the same as the record descriptor; a private final field corresponding to each component, whose name and type are the same as that of the component; a public accessor method corresponding to each component, whose name and return type are the same as that of the component. If not explicitly declared in the body of the record, implicit implementations for these members are provided.

The implicit declaration of the canonical constructor has the same accessibility as the record class and initializes the component fields from the corresponding constructor arguments. The implicit declaration of the accessor methods returns the value of the corresponding component field. The implicit declaration of the Object#equals(Object), Object#hashCode(), and Object#toString() methods are derived from all of the component fields.

The primary reasons to provide an explicit declaration for the canonical constructor or accessor methods are to validate constructor arguments, perform defensive copies on mutable components, or normalize groups of components (such as reducing a rational number to lowest terms.)

For all record classes, the following invariant must hold: if a record R's components are c1, c2, ... cn, then if a record instance is copied as follows:

R copy = new R(r.c1(), r.c2(), ..., r.cn());

then it must be the case that r.equals(copy).

Added in 16.

Java documentation for java.lang.Record.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Constructors

Properties

Methods

Explicit Interface Implementations

Extension Methods

Applies to