+ +

val

Finally! Hassle-free final local variables.

Overview

+ NEW in Lombok 0.10: You can use val as the type of a local variable declaration instead of actually writing the type. When you do this, + the type will be inferred from the initializer expression. The local variable will also be made final. This feature works + on local variables and on foreach loops only, not on fields. The initializer expression is required. +

+ val is actually a 'type' of sorts, and exists as a real class in the lombok package. You must import it for val to work (or use lombok.val as the type). + The existence of this type on a local variable declaration triggers both the adding of the final keyword as well as copying the type of the initializing expression which overwrites + the 'fake' val type. +

+ WARNING: This feature does not currently work in NetBeans. We're working on fixing that. +

With Lombok

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Vanilla Java

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Supported configuration keys:

lombok.val.flagUsage = [warning | error] (default: not set): Lombok will flag any usage of val as a warning or error if configured.

Small print

+ For compound types, the most common superclass is inferred, not any shared interfaces. For example, bool ? new HashSet() : new ArrayList() + is an expression with a compound type: The result is both AbstractCollection as well as Serializable. The type inferred will be + AbstractCollection, as that is a class, whereas Serializable is an interface. +

+ In ambiguous cases, such as when the initializer expression is null, java.lang.Object is inferred. +

+ +