Advanced Kotlin – Part 2

The resulting decompiled bytecode shows the difference between these 2:

public final class SetParamAnnTest {

@Nullable

private String myStr;

These target values along with the placement of the annotation are used to pick a default use-site target for an annotation if one is not specified.

If there's more than one applicable target either @param (constructor parameters), @property , or @field are used, in that order.

Let's see an example of this.

@NotNull

public final String getName() {

Lazy var1 = this.name$delegate;

KProperty var3 = $$delegatedProperties[0];

return (String)var1.getValue();

}

The resulting decompiled bytecode is as follows:

public final class Person {

@NotNull private final String first;

@NotNull private String last;

Setter Parameter use-site targets

As mentioned above, you can use @setparam to add annotations to setter parameters.

Let's compare @set and @setparam in the same example so you can clearly see the difference.

annotation class SetParamAnnotation

annotation class SetAnnotation

Keywords
kotlin, android