Class RecordPatternsExamples

java.lang.Object

net.jrodolfo.java_evolution.java21.RecordPatternsExamples

public class RecordPatternsExamples
extends Object

Demonstrates record patterns, finalized in Java 21.

Records make transparent data carriers concise, but code often needs to read the components back out. Before record patterns, code first checked the type, then called accessors such as rectangle.topLeft().x() to reach nested values. Record patterns let code test the type and bind record components in one expression, which is especially useful for nested records.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	RecordPatternsExamples.Point	Point record used by the nested deconstruction example.
static final record	RecordPatternsExamples.Rectangle	Rectangle record made of two points.

Constructor Summary

Constructors

Constructor	Description
RecordPatternsExamples()

Method Summary

Modifier and Type	Method	Description
String	describe(Object shape)	Deconstructs nested records in the instanceof condition.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RecordPatternsExamples

public RecordPatternsExamples()

Method Details

describe

public String describe(Object shape)

Deconstructs nested records in the instanceof condition.

If shape is a RecordPatternsExamples.Rectangle, the pattern also opens both nested RecordPatternsExamples.Point records and gives local names to their coordinates.

Parameters:

shape - the shape to describe

Returns:

a text description