Class Annotations - CUBA Platform. Developer’s Manual

@Embeddable: Defines an embedded entity stored in the same table as the owning entity.

@MetaClass annotation should be used to specify the entity name.

@EnableRestore: Indicates that the entity instances are available for recovery after soft deletion on the core$Entity.restore screen available through the Administration > Data Recovery main menu item.

@Entity

Declares a class to be a data model entity.

Parameters:

name – the name of the entity, must begin with a prefix, separated by a _ sign. It is recommended to use a short name of the project as a prefix to form a separate namespace.

Example:

@Entity(name = "sales_Customer")

@Extends: Indicates that the entity is an extension and it should be used everywhere instead of the base entity. See Functionality Extension.

@DiscriminatorColumn

Is used for defining a database column responsible for the distinction of entity types in the cases of SINGLE_TABLE and JOINED inheritance strategies.

Parameters:

name – the discriminator column name
discriminatorType – the discriminator column type

Example:

@DiscriminatorColumn(name = "TYPE", discriminatorType = DiscriminatorType.INTEGER)

@DiscriminatorValue

Defines the discriminator column value for this entity.

Example:

@DiscriminatorValue("0")

@IdSequence

Explicitly defines the name of a database sequence that should be used for generating identifiers if the entity is a subclass of BaseLongIdEntity or BaseIntegerIdEntity. If the entity is not annotated, the framework creates a sequence with an automatically generated name.

Parameters:

name – sequence name.
cached - optional parameter which defines that the sequence should be incremented by cuba.numberIdCacheSize to cache intermediate values in memory. False by default.

By default, the sequences are created in the main data store. However, if the cuba.useEntityDataStoreForIdSequence application property is set to true, sequences are created in the data store the entity belongs to.

@Inheritance

Defines the inheritance strategy to be used for an entity class hierarchy. It is specified on the entity class that is the root of the entity class hierarchy.

Parameters:

strategy – inheritance strategy, SINGLE_TABLE by default

@Listeners

Defines the list of listeners intended for reaction to the entity instance lifecycle events on the middle tier.

The annotation value should be a string or an array of strings containing bean names of the listeners. See Entity Listeners.

Examples:

@Listeners("sample_UserEntityListener")

@Listeners({"sample_FooListener","sample_BarListener"})

@MappedSuperclass

Defines that the class is an ancestor for some entities and its attributes must be used as part of descendant entities. Such class is not associated with any particular database table.

Data Modelling: Entity Inheritance guide shows the mechanism to define entity inheritance.

@MetaClass

Is used for declaring non-persistent or embedded entity (meaning that @javax.persistence.Entity annotation cannot be applied)

Parameters:

name – the entity name, must begin with a prefix, separated by a _ sign. It is recommended to use a short name of the project as prefix to form a separate namespace.

Example:

@MetaClass(name = "sales_Customer")

@NamePattern

Defines how to create a string which represents a single instance of the entity. Think of it as of an application level toString() method. It is used extensively in UI when displaying an entity instance in a single field like TextField or LookupField. You can also get the instance name programmatically using the MetadataTools.getInstanceName() method.

The annotation value should be a string in the {0}|{1} format, where:

{0} – format string which can be one of two types:
- A string with %s placeholders for formatted values of entity attributes. Attribute values are formatted to strings according to their datatypes.
- A name of this object’s method with the # prefix. The method should return String and should have no parameters.
{1} – a list of attribute names separated by commas, corresponding to {0} format. If a method is used in {0}, the list of fields is still required as it forms the _minimal view.

Examples:

@NamePattern("%s|name")

@NamePattern("%s - %s|name,date")

@NamePattern("#getCaption|amount,customer")
...
public String getCaption(){
    String prefix = "";
    if (amount > 5000) {
        prefix = "Grade 1 ";
    } else {
        prefix = "Grade 2 ";
    }
    return prefix + customer.name;
}

@PostConstruct

This annotation can be specified for a method. The annotated method will be invoked right after the entity instance is created by the Metadata.create() method or similar DataManager.create() and DataContext.create() methods.

See Initial Entity Values guide for an example of defining initial values directly in the entity class using the @PostConstruct annotation.

The annotated method can accept Spring beans available in the global module as parameters. For example:

@PostConstruct
public void postConstruct(Metadata metadata, SomeBean someBean) {
    // ...
}

@PrimaryKeyJoinColumn

Is used in the case of JOINED inheritance strategy to specify a foreign key column for the entity which refers to the primary key of the ancestor entity.

Parameters:

name – the name of the foreign key column of the entity
referencedColumnName – the name of primary key column of the ancestor entity

Example:

@PrimaryKeyJoinColumn(name = "CARD_ID", referencedColumnName = "ID")

@PublishEntityChangedEvents: Indicates that EntityChangedEvent should be sent by the framework when the entity is changed in the database.

@SystemLevel: Indicates that the entity is system only and should not be available for selection in various lists of entities, such as generic filter parameter types or dynamic attribute type.

@Table

Defines database table for the given entity.

Parameters:

name – the table name

Example:

@Table(name = "SALES_CUSTOMER")

@TrackEditScreenHistory: Indicates that editor screens opening history will be recorded with the ability to display it on the sec$ScreenHistory.browse. The screen can be added to the main menu using the following element of web-menu.xml:

3.2.1.2.1. Class Annotations