@Beanc Annotation

The @Beanc annotation is used to map constructor arguments to property names on bean with read-only properties.

Since method parameter names are lost during compilation, this annotation essentially redefines them so that they are available at runtime.

The definition of a read-only bean is a bean with properties with only getters, like shown below:

// Our read-only bean.
public class Person {
    private final String name;
    private final int age;

    @Beanc(properties="name,age"})
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    // Read only properties.
    // Getters but no setters.

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}

// Parsing into a read-only bean.
String json = "{name:'John Smith',age:45}";
Person person = Json.to(json, Person.class);
String name = person.getName();  // "John Smith"
int age = person.getAge();   // 45

Beans can also be defined with a combination of read-only and read-write properties.

The @Name annotation can also be used instead of @Beanc(properties):

@Beanc
public Person(@Name("name") String name, @Name("age") int age) {
    this.name = name;
    this.age = age;
}

If neither @Beanc(properties) or @Name is used to identify the bean property names, we will try to use the parameter names if they are available in the bytecode.