javax.persistence

## Annotation Type Id

    @Target(value={METHOD,FIELD})
     @Retention(value=RUNTIME)
    public @interface Id

Specifies the primary key of an entity. The field or property to which the `Id` annotation is applied should be one of the following types: any Java primitive type; any primitive wrapper type; `String`; `java.util.Date`; `java.sql.Date`; `java.math.BigDecimal`; `java.math.BigInteger`.

The mapped column for the primary key of the entity is assumed to be the primary key of the primary table. If no `Column` annotation is specified, the primary key column name is assumed to be the name of the primary key property or field.

       Example:

       @Id
       public Long getId() { return id; }

See Also:
  `Column`, `GeneratedValue`
Since:
  Java Persistence 1.0