juneau-doc/docs/Topics/02.juneau-marshall/13.VirtualBeans.html

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Virtual Beans

<p>
	The {@link oaj.BeanContext#BEAN_useInterfaceProxies} setting (enabled by default) allows
	the Juneau parsers to parse content into virtual beans (bean interfaces without implementation classes).
</p>
<p>
	For example, the following code creates an instance of the specified unimplemented interface:
</p>
<p class='bpcode w800'>
	<jc>// Our unimplemented interface</jc> 
	<jk>public interface</jk> Address {
		
		String getStreet();
		<jk>void</jk> setStreet(String x); 
		
		String getCity();
		<jk>void</jk> setCity(String x); 

		StateEnum getState();
		<jk>void</jk> setState(StateEnum x); 
		
		<jk>int</jk> getZip();
		<jk>void</jk> setZip(<jk>int</jk> zip);
	}
	
	<jc>// Our code</jc>
	Address address = JsonParser.<jsf>DEFAULT</jsf>.parse(
		<js>"{street:'123 Main St', city:'Anywhere', state:'PR', zip:12345}"</js>, 
		Address.<jk>class</jk>
	); 
	
	<jk>int</jk> zip = address.getZip();
	address.setState(StateEnum.<jsf>NY</jsf>);
</p>
<p>
	Getter and setter values can be any {@doc PojoCategories parsable} values, even other virtual beans.
</p>
<p>
	Under-the-covers, a virtual bean is simply a proxy interface on top of an existing <c>BeanMap</c>
	instance.  From a programmatic point-of-view, they're indistinguishable from real beans, and can be 
	manipulated and serialized like any other bean.
</p>	
<p>
	Virtual beans can also be created programmatically using the <c>BeanContext</c> class:
</p>
<p class='bpcode w800'>
	Address address = BeanContext.<jsf>DEFAULT</jsf>.createSession().newBean(Address.<jk>class</jk>);
</p>