net.sf.mmm.util.bean.api

Interface Bean

All Known Subinterfaces:

AbstractArea, AbstractArtist, AbstractCode, AbstractGenre, AbstractLocalizedName, AbstractLocation, AbstractMedia, AbstractName, AbstractTrack, Address, ArtistGroup, ArtistMember, ArtistPerson, AudioAlbum, AudioGenre, AudioTrack, City, Country, DeBundesland, DeGemeinde, DeGemeindeteil, DeLandkreis, DeRegierungsbezirk, Edge, EntityBean, File, FrDepartement, IeCounty, Language, OrientBean, Person, PostalCode, Region, TypedEdge, UsState, Vertex, VideoTrack

public interface Bean

This is the interface for a generic bean based on generic properties. Unlike plain old Java Beans this offers a lot of advanced features:

• Simplicity - just create your interface, no need to write boiler-plate code for implementation.
• Generic - fast, easy and reliable introspection via BeanAccess.getProperties(). No greedy introspection via reflection for each access but only once per Bean interface.
• Dynamic - supports combination of Java's strong typing with dynamic beans. E.g. if read data from Database, XML, or JSON you can still map "undefined" properties in your Bean. This way a client can receive an object from a newer version of a database or (REST-)service with added properties that will be kept in the object and send back when the Bean is written back.
• Automatic - no need to implement methods such as #equals(Object), #hashCode(), or #toString(). Also general getters and setters are automatically implemented.
• Flexibility - add any custom logic to your Bean interface via default methods including custom implementations of equals and hashCode if needed.
• ReadOnly-Support - create a read-only view of your object to pass by reference without side-effects.
• Powerful properties - WritableProperty is based on JavaFx Property supporting listeners and bindings but also additional features such as generic type information.
• Validation - build-in validation support. This can be configured via Bean-Validation standard (JSR303) or even more efficient and reusable via custom properties or in default methods for the properties of your Bean interface.
• JSON-Support - mapping from and to JSON is already build in and is extremely efficient. If you need custom datatypes you can simply extend GenericProperty and tweak the JSON mapping as needed. No separate classes for mapping from or to JSON are required - also not for database if you use Java standard datatypes as value and keep your custom logic in the property.
• Portability - everything relies only on established Java default mechanisms such as dynamic proxies. No customization of build processes, IDEs, etc. needed. It just works with any build tool (maven, gradle, buildr, ant, etc.) and IDE (Eclipse, IntelliJ, NetBeans, etc.) without plugins and therefore will also work in the future whatever may come..

In order to define your own bean simply create a new interface (directly or indirectly) extending this Bean interface as in the following example:

 public interface AddressBean extends Bean {
   StringProperty Street();
   StringProperty HouseNumber();
   StringProperty PostalCode();
   StringProperty City();
   StringProperty Country();
   // if you want you may also define regular getters and setters as well
   String getStreet();
   void setStreet(String street);
 }
 

In order to create a new instance of AddressBean simply do this:

 public void MyClass {

   @Inject
   private BeanFactory beanFactory;

   public void doSomething() {
     AddressBean address = this.beanFactory.create(AddressBean.class);
     address.Street().setValue("Baker Street");
     address.HouseNumber().setValue("1a");
     address.PostalCode().setValue("6wn7ta");
     address.City().setValue("Rafferty");
     address.Country().setValue("Gerryland");
     for (Property <?> property: address.access().getProperties()) {
       System.out.println("Property '" + property.getName() + "' of type ' + property.getType() + ' has value '" + property.getValue() + "'.");
     }
   }
 }
 

If you are very pragmatic do not like Ioc you can also use BeanFactoryImpl.getInstance(). For most simplistic fabrication you can create a static method to your Bean:

 static AddressBean create() {
   return BeanFactoryImpl.getInstance().create(AddressBean.class);
 }
 

Since:

8.0.0

Author:

hohwille

Method Summary

Modifier and Type	Method and Description
BeanAccess	access()

Method Detail

access

BeanAccess access()

Returns:

the BeanAccess with all generic features and methods on a Bean. These are encapsulated in BeanAccess to avoid polluting this Bean interface itself with additional methods and for better compatibility on enhancements.