On Fri, 26 Mar 2021 15:15:48 GMT, Daniel Fuchs <dfu...@openjdk.org> wrote:
>> This RFE proposes to extend the MXBean framework to define a mapping to
>> records.
>>
>> The MXBean framework already defines a mapping of `CompositeType` to plain
>> java objects. Records are a natural representation of CompositeTypes. A
>> record can be easily reconstructed from a `CompositeData` through the record
>> canonical constructor. A clear advantage of records over plain java objects
>> is that the canonical constructor will not need to be annotated in order to
>> map composite data property names to constructor parameter names.
>>
>> With this RFE, here is an example comparing coding a composite type
>> `NamedNumber` that consists of an `int` and a `String`, using records and
>> using a plain java class. In both case, the `CompositeType` looks like this:
>>
>> CompositeType(
>> "NamedNumber", // typeName
>> "NamedNumber", // description
>> new String[] {"number", "name"}, // itemNames
>> new String[] {"number", "name"}, // itemDescriptions
>> new OpenType[] {SimpleType.INTEGER,
>> SimpleType.STRING} // itemTypes
>> );
>>
>> The plain Java class needs a public constructor annotated with
>> `@ConstructorParameters` annotation:
>>
>> public class NamedNumber {
>> public int getNumber() {return number;}
>> public String getName() {return name;}
>> @ConstructorParameters({"number", "name"})
>> public NamedNumber(int number, String name) {
>> this.number = number;
>> this.name = name;
>> }
>> private final int number;
>> private final String name;
>> }
>>
>> And the equivalent with a record class:
>>
>> public record NamedNumber(int number, String name) {}
>
> Daniel Fuchs has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Fixed typo. Moved example with record after example with from method to
> respect the logical order of precedence.
src/java.management/share/classes/javax/management/MXBean.java line 757:
> 755:
> 756: <p>If the class is a {@link Record}, its getters are the
> 757: accessors for the record components. Otherwise, the
It may be good to add a link like {@linkplain RecordComponent record components}
-------------
PR: https://git.openjdk.java.net/jdk/pull/3201
