Public:BWmeta service/Java mapping

From YaddaWiki

Service details
Name	BWmeta
Code location (relative to SVN root)	projects/dir/bwmeta-core
Javadoc
Contact person	Jakub Jurkiewicz
edit BWmeta format Data Model BWMeta Model Design principles 1.0.5 example 1.2.0 example 2.0.0 example Feature requests Linked Open Data Hierarchys Book Journal BWmeta usage in YADDA Java mapping Rich text in Java mapping Transformers data sources Conventions and constants Contents and attachments Internationalization Tutorial How to convert to Dublic Core? Categorizations

General contracts

Unless explicitly stated in the documentation, every "Y" class has the following properties:

• has a public empty constructor.
• every property is protected, but has a public getter and setter.
• every setter and every list adder returns this, which allows chained setting, e.g.:

new YElement()
    .setId("bwmeta1.element.foo")
    .addName(new YName().setText("Foo").setLanguage(YLanguage.English))
    .addDescription(new YDescription().setText("Lorem ipsum").setLanguage(YLanguage.Latin));

• getters of String, YLanguage and List properties can never return null. Instead, an empty String, YLanguage.Undetermined or an empty List is returned, respectively.
• every List property has an adder (which returns this).
• for every List<T> property:
  • its getter returns a modifiable List<T>;
  • its getter returns the same reference all the time;
  • its setter accepts any Collection<T> (and copies the contents);
  • there's an adder (which returns this).

The folowing contracts are to be implemented/verified in the future:

• hashCode() and equals() methods are based on the values of all the properties, i.e., two "Y" objects are equal iff they are of the same type and all their properties are equal.