Document it is possible to use Java Records for immutable configuration with @ConfigurationProperties

src/main/docs/guide/config/immutableConfig.adoc

@@ -55,6 +55,16 @@ snippet::io.micronaut.docs.config.immutable.VehicleSpec[tags="start",indent=0,ti
 
 The above example prints: `"Ford Engine Starting V8 [rodLength=7B.0]"`
 
+==== Using Java Record Classes to define immutable configuration
+
+For Java language applications, it's also possible to use https://docs.oracle.com/en/java/javase/17/language/records.html[Java Record Classes] for immutable configuration with ann:context.annotation.ConfigurationProperties[]. For example:
+
+snippet::io.micronaut.docs.config.immutable.ValueAddedTaxConfiguration[tags="imports,class",title="Java Record Example"]
+
+<1> The `percentage` field defines a configuration property for "vat"
+
+NOTE: From a performance perspective Java records are better than interfaces.
+
 == Customizing accessors
 
 As already explained in <<configurationPropertiesAccessorsStyle, Change accessors style>>, it is also possible to customize the accessors when creating immutable configuration properties:

test-suite/src/test/java/io/micronaut/docs/config/immutable/ValueAddedTaxConfiguration.java

@@ -0,0 +1,17 @@
+package io.micronaut.docs.config.immutable;
+
+// tag::imports[]
+import io.micronaut.context.annotation.ConfigurationProperties;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.core.annotation.NonNull;
+import jakarta.validation.constraints.NotNull;
+import java.math.BigDecimal;
+// end::imports[]
+
+@Requires(property="spec.name", value="ValueAddedTaxConfigurationTest")
+// tag::class[]
+@ConfigurationProperties("vat")
+public record ValueAddedTaxConfiguration(
+    @NonNull @NotNull BigDecimal percentage) { // <1>
+}
+// end::class[]

test-suite/src/test/java/io/micronaut/docs/config/immutable/ValueAddedTaxConfigurationTest.java

@@ -0,0 +1,25 @@
+package io.micronaut.docs.config.immutable;
+
+import io.micronaut.context.BeanContext;
+import io.micronaut.context.annotation.Property;
+import io.micronaut.test.extensions.junit5.annotation.MicronautTest;
+import jakarta.inject.Inject;
+import org.junit.jupiter.api.Test;
+import java.math.BigDecimal;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@Property(name = "spec.name", value="ValueAddedTaxConfigurationTest")
+@Property(name = "vat.percentage", value = "21.0")
+@MicronautTest(startApplication = false)
+class ValueAddedTaxConfigurationTest {
+
+    @Inject
+    BeanContext beanContext;
+
+    @Test
+    void immutableConfigurationViaJavaRecords() {
+        assertTrue(beanContext.containsBean(ValueAddedTaxConfiguration.class));
+        assertEquals(new BigDecimal("21.0"), beanContext.getBean(ValueAddedTaxConfiguration.class).percentage());
+    }
+}