Add support for @Immutable attribute types

Description

Currently, @Immutable works for entities and collections, as indicated by ANN-542.

By adding support for attribute types, we can benefit from:

lower memory consumption (no need to create copies for checking if entity is dirty or to put/read it from cache) - especially in cases where entity contains JSON documents
faster flush operations

An immutable attribute type looks like this:

@Immutable
public class Caption {

	private String text;

	public Caption(String text) {
		this.text = text;
	}

	public String getText() {
		return text;
	}

	public void setText(String text) {
		this.text = text;
	}

	@Override
	public boolean equals(Object o) {
		if ( this == o ) {
			return true;
		}
		if ( o == null || getClass() != o.getClass() ) {
			return false;
		}
		Caption caption = (Caption) o;
		return text != null ? text.equals( caption.text ) : caption.text == null;

	}

	@Override
	public int hashCode() {
		return text != null ? text.hashCode() : 0;
	}
}

And it is used as follows:

@Entity
@SuppressWarnings("serial")
public class Photo implements Serializable {

	private Integer id;

	private String name;

	private Exif metadata;

	private Caption caption;

	@Id
	@GeneratedValue
	public Integer getId() {
		return id;
	}

	public String getName() {
		return name;
	}

	public void setId(Integer integer) {
		id = integer;
	}

	public void setName(String string) {
		name = string;
	}

	public Exif getMetadata() {
		return metadata;
	}

	public void setMetadata(Exif metadata) {
		this.metadata = metadata;
	}

	@Convert(converter = CaptionConverter.class)
	public Caption getCaption() {
		return caption;
	}

	public void setCaption(Caption caption) {
		this.caption = caption;
	}
}

The @Immutable annotation still cannot be applied on fields directly, but it can work on an attribute type as illustrated above.

Activity

Show:

Vlad Mihalcea May 18, 2016 at 2:37 PM

The PR was applied on master. Thanks for your contribution.

Fixed

Details

Assignee

Vlad Mihalcea

Reporter

Vlad Mihalcea

Components

hibernate-core

Fix versions

5.2.0

Priority

Major

Created April 28, 2016 at 9:39 AM

Updated June 2, 2016 at 3:50 AM

Resolved May 18, 2016 at 2:37 PM

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