{title:'@Beanc Annotation', updated:'8.1.0,8.1.2'}

The {@link oaj.annotation.Beanc @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 = JsonParser.DEFAULT.parse(json); | 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 {@link oaj.annotation.Name @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.