Bob now knows his ancestors: Builders with fields from superclasses, too.
@SuperBuilder was introduced as experimental feature in lombok v1.18.2.
toBuilder feature and limited support for customization was added with lombok v1.18.4.
@SuperBuilder annotation produces complex builder APIs for your classes.
In contrast to
@SuperBuilder also works with fields from superclasses.
However, it only works for types, and customization possibilities are limited.
Most importantly, it requires that all superclasses also have the
@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
@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
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
FoobarBuilderImpl (where Foobar is the name of the annotated class).
Customizing the code generated by
@SuperBuilder is limited to adding new methods or annotations to the builder classes, and providing custom implementations of
You have to make sure that the builder class declaration headers match those that would have been generated by lombok. Due to the heavy generics usage, we strongly advice to copy the builder class definition header from the uncustomized delomboked code.
The configurable aspects of builder are:
The build() method's name (default:
The builder() method's name (default:
If you want
@SuperBuilder(buildMethodName = "execute", builderMethodName = "helloWorld", toBuilder = true)
Supported configuration keys:
error] (default: not set)
Lombok will flag any usage of
@SuperBuilderas a warning or error if configured.
false] (default: false)
true, lombok will use guava's
ImmutableXxxbuilders and types to implement
java.utilcollection 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
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:
NavigableMap and guava:
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.
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
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.