Android Reflection Fails for Annotation

Question

having difficulty getting information about a fields annotation

here is my annotation:

public @interface DbField {}

here is my class:

public class AccountData extends Data {

    @DbField
    public String uidnext;

here is my reflection

Field f = AccountData.class.getField("uidnext");
Log.d("fcrow", String.format("%s:%b", f.getName(),
                f.getAnnotation(DbField.class) != null));

output is:

D/fcrow: uidnext:false

I'm confused most of what I can find online points to this code working.

Answer 1

Modify your annotation declaration to include a runtime retention policy:

@Retention(RetentionPolicy.RUNTIME)
public @interface DbField {}

If you do not do this, you will get the default retention policy CLASS . Its documentation states:

Annotations are to be recorded in the class file by the compiler but need not be retained by the VM at run time. This is the default behavior.