#import "../_features.html" as f> <@f.scaffold title="@SuperBuilder" logline="Bob now knows his ancestors: Builders with fields from superclasses, too. "> <@f.history>
@SuperBuilder
was introduced as experimental feature in lombok v1.18.2.
The @SuperBuilder
annotation produces complex builder APIs for your classes.
In contrast to @Builder
, @SuperBuilder
also works with fields from superclasses.
However, it only works for types, and cannot be customized by providing a partial builder implementation.
Most importantly, it requires that all superclasses also have the @SuperBuilder
annotation.
@SuperBuilder
lets you automatically produce the code required to have your class be instantiable with code such as:
Person.builder().name("Adam Savage").city("San Francisco").job("Mythbusters").job("Unchained Reaction").build();
@SuperBuilder
can generate so-called 'singular' methods for collection parameters/fields. For details, see the @Singular
documentation in @Builder
.
@SuperBuilder
generates a private constructor on the class that takes a builder instance as a parameter. This constructor sets the fields of the new instance to the values from the builder.
@SuperBuilder
is not compatible with @Builder
.
You can use @SuperBuilder(toBuilder = true)
to also generate an instance method in your class called toBuilder()
; it creates a new builder that starts out with all the values of this instance. You can put the @Builder.ObtainVia
annotation on the fields to indicate alternative means by which the value for that field/parameter is obtained from this instance. For example, you can specify a method to be invoked: @Builder.ObtainVia(method = "calculateFoo")
.
To ensure type-safety, @SuperBuilder
generates two inner builder classes for each annotated class, one abstract and one concrete class named FoobarBuilder
and FoobarBuilderImpl
(where Foobar is the name of the annotated class).
The configurable aspects of builder are:
"build"
)
"builder"
)
toBuilder()
(default: no)
@SuperBuilder(buildMethodName = "execute", builderMethodName = "helloWorld", toBuilder = true)
lombok.superBuilder.flagUsage
= [warning
| error
] (default: not set)
@SuperBuilder
as a warning or error if configured.
lombok.singular.useGuava
= [true
| false
] (default: false)
true
, lombok will use guava's ImmutableXxx
builders and types to implement java.util
collection interfaces, instead of creating implementations based on Collections.unmodifiableXxx
. You must ensure that guava is actually available on the classpath and buildpath if you use this setting. Guava is used automatically if your field/parameter has one of the guava ImmutableXxx
types.
lombok.singular.auto
= [true
| false
] (default: true)
true
(which is the default), lombok automatically tries to singularize your identifier name by assuming that it is a common english plural. If false
, you must always explicitly specify the singular name, and lombok will generate an error if you don't (useful if you write your code in a language other than english).
@Singular support for java.util.NavigableMap/Set
only works if you are compiling with JDK1.8 or higher.
The sorted collections (java.util: SortedSet
, NavigableSet
, SortedMap
, NavigableMap
and guava: ImmutableSortedSet
, ImmutableSortedMap
) require that the type argument of the collection has natural order (implements java.util.Comparable
). There is no way to pass an explicit Comparator
to use in the builder.
An ArrayList
is used to store added elements as call methods of a @Singular
marked field, if the target collection is from the java.util
package, even if the collection is a set or map. Because lombok ensures that generated collections are compacted, a new backing instance of a set or map must be constructed anyway, and storing the data as an ArrayList
during the build process is more efficient that storing it as a map or set. This behaviour is not externally visible, an implementation detail of the current implementation of the java.util
recipes for @Singular
.
The generated builder code heavily relies on generics to avoid class casting when using the builder.
Various well known annotations about nullity cause null checks to be inserted and will be copied to parameter of the builder's 'setter' method. See Getter/Setter documentation's small print for more information.
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